3. Operations Displays

3.1 WAC Display: WUPPE Activation
3.2 WCO Display: WUPPE Checkout
3.2.1 Special Procedure SPEC (SP)
3.2.2 Special Procedure ZOD/ CCTV (ZO)
3.2.3 Special Procedure APER/ FIL (AF)
3.2.4 Special Procedure SEC MTR (SM)
3.2.5 Special Procedure IMC (IM)
3.2.6 Special Procedure MEM (MY)
3.2.7 Special Procedure PARAM (PA)
3.3 WOB: WUPPE Observation
3.4 WED: WUPPE Sequence Edit
3.5 WNG: WUPPE Engineering
3.6 JAC: Joint Acquisition and JOB: Joint Observation
3.7 CCTV Displays and Audio

During the mission, commands to the UV experiments during nominal operations are given by the Payload Specialists (PS). The commands are keyed in on the Data Display Unit, DDU, located on the Shuttle Aft Flight Deck. The Payload Specialists also have at their disposal a Closed Circuit Television, or CCTV, screen to review images and spectral data (see 3.7). Commanding to the BBXRT will be accomplished remotely from Goddard Space Flight Center (GSFC). The Principal Investigators and their teams (PI) monitor the CCTV and the data sent in the High-Rate Multiplexer data stream (HRM) to their Ground-Support Equipment (GSE).

The DDU provides a menu of display pages. During nominal operations, the Payload Specialists will operate the instruments from the "Joint" pages. These pages allow for monitoring and control of all UV-instrument operations simultaneously. The individual instruments also have individual display pages (numbers and styles depending on instrument requirements) which give information on vital engineering data and observational parameters for each of the instruments. The page names consist of 3 letters, starting with a "W" for WUPPE pages, "H" and "U" for the HUT and UIT pages, and a "J" for the joint pages, respectively. Commands to the instruments have the form of numbers, and sometimes a number accompanied by an alphanumeric parameter. These numbers for commands to the instruments, the so-called Item Entries (IE), are listed for convenient reference in front of each menu item. Some commanding is achieved by using Programmed Function Keys (PFKs). Commands from the DDU are sent to the instruments via the Experiment Computer, which is located in the Spacelab Igloo.

All WUPPE commanding by the Experiment Computer (EC) is accomplished by Item Entries and Program Function Keys, using the 4 WUPPE-only ECOS (EC Operating System) displays and/or the 2 joint ECAS (EC Application Software) displays, and the CCTV.

The EC drives the displays through wires and through a serial line to the DEP. The wires forward the so-called hardware commands. For WUPPE, the WAC page (see below) is a systems display. Some values on the WAC page are valid whenever power is applied to Spacelab, while the other WUPPE pages contain valid data only when the DEP is up.

Figure 3.0-1: WUPPE-Spacelab interactions, from viewpoint of PS and PI.

The communication from WUPPE electronics to the EC goes via one of the Remote Acquisition Units (RAU). The direction of communication flow is defined as seen from the RAU, and can be in the form of Analog Input (AI), Digital Input (DI) or groups of DIs called DGs, and Digital Output, DO. DEP commands use serial messages on a serial line to send commands between the EC and the DEP, which the DEP then executes. There is Serial Input, SI, and Serial Output, SO. Communication over the serial lines is also referred to as DEP/ EC protocol. Protocol is initiated by the DEP, which sends data solicits to the EC once every second.

DEP displays contain valid data only when power is applied to the DEP, i.e. LVPS on, and DEP running. LVPS and DEP are usually activated early on in the mission/ testing procedure, after completion of Spacelab checkout. The WUPPE pages WOB, WED, and WCO (see below) are referred to as DEP displays. Serial message (SI) #1 is sent once/ sec, and data are consequently updated at this rate. Serial meassage #2 is used mostly for the WED page. The DEP also receives a clock signal, UTC, from the EC.

The DEP sends out data in the High-Rate Multiplexer (HRM) data stream and on the Video line. The data are downlinked via K-band transmission to the Payload Operations Control Center, POCC, which demultiplexes and forwards the information to the PI. The PI generates the WUPPE pages and CCTV on the GSE. POCC also sends the Video signal which can be seen on the WUPPE OGSE video monitor.

Video signals from the DEP are also received by the PS on the AFD CCTV. In order to move the cursor on the CCTV, the PS uses the PFKs on the DDU. The commands are sent to through the EC and the RAU to the DEP, the DEP processes the request, and the cursor then moves on the CCTV display. Most item-entry commands given by the PS from the joint pages (JAC, JOB) have the same meaning as on the WUPPE pages, the commands are also called DEP/ joint commands.

The spacelab EC transmits to and receives data from the POCC via K- and S-band channels through ECIO, the EC Input Output. The POCC generates the POCC displays from the high-rate data stream, i.e. K-band transmission. The POCC displays thus provide a contingency for WUPPE operations without DEP and LVPS off, or DEP crashed (while LVPS on). In this event, some crucial values on the WAC page (and also some values on WCO) which do not need the DEP can still be read. Note that the GSE is "blind" without HRM data from the DEP. It is also over the ECIO data route that ground commands to WUPPE are uplinked from POCC to the EC. ( Cape testing: substitute POCC by Payload Checkout Unit, PCU, and POCC displays by HITS displays.)

Data from WUPPE are sent over K-band; the S-band could in principal be used, but WUPPE is not configured that way for Astro-1. The following is a description of the downlink and uplink data flow. The Spaceflight Tracking and Data Network (STDN) is composed of two major tracking elements: the Space Network, also referred to as the TDRS system, and the Ground Network, also called GSTDN. High-rate data flow from the Orbiter to the POCC and PI is accomplished by the TDRS (Telemetry and Data Relay Satellite) system. This system of geosynchronous stellites allows the Orbiter to have line-of-sight transmission capability to at least one TDRS satellite most of the time. All on-board data can be transmitted through the K-band system to the TDRS system. The data are routed via TDRS to a ground station (White Sands), processed into a domestic satellite system (DOMSAT), and received at Marshall for demultiplexing and distribution within the POCC. S-band can be used to downlink operational downlink (i.e. orbiter data) and voice communication when K-band is not available. These low-rate data are either sent through TDRS or are downlinked directly to one of eight ground stations in the GSTDN, the Ground Spaceflight Tracking and Data Netwok, from where they are sent via GSFC or JSC (video) to the POCC. The K-band provides uplink via TDRS for command, voice, the Text and Graphics System, and the teleprinter. The S-band provides uplink via GSTDN and TDRS for command and voice. One peculiarity of the TDRS system is that the economics of having only one ground station results in a Zone of Exclusion (ZOE), an area where the shadow of the earth prevents a spacecraft from being viewed. The average projected coverage obtainable from the TDRS system will be approximately 85% of the orbit for S-band and 50-65% for K-band (depending on orbital altitude). The percentages for S-band and K-band coverages are different because of Orbiter blockage which affects the K-band. No S-band or K-band downlink service is available when the center of the sun is within 4° - 1° of the TDRS antenna boresight. For WUPPE, no K-band downlink means no HRM data, neither on the GSE nor on the POCC displays. Such data will have to be recovered by playback.

There are many elements within the end-to-end data flow which can temporarily or permanently cause loss of data to the user:

- On-board failure within the High-Rate System - switch to lower data rate with S-band and GSTDN (degraded mode, no HRM data).

- Failure within TDRS system - use on-board recorder and dump data later through healthy TDRS satellite.

- Failure at White Sands ground terminal or any GSTDN station - temporary data dropouts til fixed (degraded mode).

Since WUPPE does not have the capability to use S-band, there will be no data coming from the DEP when there is no TDRS coverage. When the DEP is not up (i.e. in survival or crashed) but TDRS is covering, the PI can use the POCC displays to monitor experiment performance. During K-band LOS, no high-rate data are being sent down from the Orbiter. However, some infomation implemented in the Orbiter housekeeping S-band data appear on the displays (i.e. error messages on the scratch-pad line).

The operating system of the EC is ECOS (EC Operating System). One function of ECOS is to look at values, and to report when they go out of their specified limits. This function is called "exception monitoring". The values are given on the "Magic forms". The Magic forms are tables which equate measurement values (i.e. Volts or Amps) into instrumental engineering units. The Signal IDentifier list, or SID list, in the WUPPE Payload Flight Data File, PFDF, lists limiting values for certain instrumental parameters. ECOS reports when a parameter goes out of limits by sending an error message to the displays. For WUPPE DEP and EC values to have the same meaning to the GSE and POCC, the PI and POCC have defined a cross calibration for the data. POCC converts values received from the EC via ECIO using the POCC data base. The EC Application Software, or ECAS, is a specific, higher level software. For instance, the Joint ECAS "IJOP" is used to send commands to several instruments at a time. The joint displays are then ECAS displays.

WUPPE Item/PFK numbers are distinct and unique, that is a particular number has the same function on all display pages, even between joint and WUPPE-only pages. The sole exception is for those Item Entries on the joint displays where data are forwarded by ECAS (Items 1, 7, 9, and 10); when these are executed from WUPPE pages, they must be accompanied by keyed-in data as indicated on the displays. A summary of WUPPE commands is given in the WUPPE PFDF. It is strongly recommended to refer to the PFDF while reading the following sections of the WUPPE OPS manual.

The WUPPE-only displays are shown in the WUPPE PFDF. These displays are used for instrument turn-on and checkout, monitoring experiment parameters, and contingency activities. If necessary, WUPPE could be operated solely from these displays throughout the ASTRO missions. The WUPPE Activation page (WAC) is an ECOS-monitor display. The other three are DEP-ECOS displays; they cannot be utilized until the DEP is on. WUPPE has a fifth page, WNG. A ground-only display used to monitor WUPPE engineering data, the WNG page cannot be used for commanding. The WNG page is available on the GSE, buton the DDU. Problems discovered here during the mission will be voiced up to the crew. The functions of the displays are as follows:

The WUPPE Activation Display (WAC)

(A.) Most non-DEP functions

(B.) Heater control, temperature monitoring

(C.) Redundant mode selection

(D.) DEP power activation, power monitoring

(E.) Backup-door mechanism operation

The WUPPE Checkout Display (WCO)

(A.) Camera, spectrometer activation

(B.) TEC activation

(C.) WUPPE IMC actuator activation

(D.) Contingency devices: test lamp, EEROM write, monitor

(E.) Add-on special procedures: hardware checkout and calibration, MMU load

The WUPPE Observation Display (WOB)

(A.) Supporting Joint Acquisition/Observation Displays

(B.) Instrument-specific commands and data

(C.) ECAS-independent operation for checkout

The WUPPE Sequence Edit Display (WED)

(A.) ECAS-independent sequence creation

(B.) Display/edit of preview and current sequence buffers

(C.) Completion summary for current object

The WUPPE Engineering Display (WNG)

(A.) Shows actions of several vital motors

(B.) TEC thermistor readings

(C.) Door-microphone (audio) analog reading

Except for instrument turn-on, shutdown for landing, and contingency activities, WUPPE is controlled during the flight from the 2 joint ECAS displays. These two displays are designed to control all three instruments simultaneously. They are shown in the JOPS PFDF.

The Joint Acquisition Display (JAC)

(A.) Previews an upcoming observation

(B.) Acquires targets which are to be observed

(C.) Begins observing each source

The Joint Observations Display (JOB)

(A.) Monitors an observation in progress

(B.) Initiates pauses in the observations

(C.) Terminates observations

Several predefined PFKs, shown in Figure 3.0-2, permit commands from joint displays to be directed to one or all of the experiments. This is referred to as command routing. The joint displays (JAC, JOB), the WAC display and 2 of the WUPPE-DEP displays are allocated at any one time and are available to the Payload Specialist (PS). Of the DEP displays the WOB will always be allocated and the WCO and WED will be switched in and out using Item-Entry Commands. (This is due to limited space availability in the EC.)

Error messages from EC exception monitoring and the DEP are reported on the EC error line (line 20). Tutorial messages are shown on line 19. Tables of all WUPPE error messages and tutorial messages are given in the PFDF.

A video signal which feeds the Aft Flight Deck CCTV is driven by the WUPPE DEP. It shows a field or zoom (8x magnification) of the Zero-Order-image starfield, or a graphic representation of the spectral data being acquired by the spectropolarimeter. The format of these displays is shown in section 3.7. The arrow and fine/ coarse PFKs are used to manipulate a DEP-generated cursor on the CCTV during manual operations.

The feedback on WUPPE pages can have the form of changing engineering values, like Volts or Amps. A message line informs the operator of functions in progress following a more intricate command. Actions or states are also indiated by the presence or absence of bugs, the * symbol, next to an item. Some Item Entries toggle between two states; when the item is performed once, it takes action #1, if entered again, action #2 takes place (which usually undoes the previous command). In addition, there are so-called special procedures, which are used for very specific purposes and contingencies only. When called up, a submenu appears on the WUPPE page, referred to as add-on.

 

 

Figure 3.0-2 : Programmed Function Key Layout.

Of all Tables given in the WUPPE PFDF, the SID list is the least self explanatory one. The columns in the SID list are signal name, SID number (which is also the numerical parameter used in commanding concerning that signal), SIG gives the signal type, i.e. AI, DI etc., next is the channel on RAU 6 used by this signal, ECOS UL and LL are upper and lower boundaries of values, this is used for reference and exception monitoring, JOPS I13 gives the level (1 or 2) of IE13 on the joint pages (IE 13 enable/ disenable exception monitoring), and conditions when a reading is valid, and the unpowered or default reading of a signal. The validity conditions are +12, meaning valid after LVPS is powered; I53, meaning IE 53 i.e. valid after Temp Monitor DO activated; and IPSBS, meaning valid as long as Spacelab (S/L) is powered.

Some vital WUPPE subsystems exist twice, i.e. there is a primary and a redundant backup unit. Throughout the Ops manual, the primary system is called "A". However, during the mission, the primary system is not necessarily "A". When WUPPE is unpowered, most values read in fact "B" (see the SID list). In FO-1 (Activation to Survival, see PFDF) WUPPE is first activated during the mission (or testing), and there is a Table of WUPPE Redundant Systems. The launch values are to be penciled in by the PS just before flight. Latch comes up as "B", and will be selected by procedure (FO-1, step 2). Heater, DEP, and RAM are latched on the ground. CCD OSC "A" or "B" will be set by software (i.e. in DWUP02).

The last page of the WUPPE PFDF is a CCTV overlay. It shows sizes of image fields and apertures on the CCTV screen in Field, Zoom and Spectrum-display modes (see also section 3.7).

Apart from the WUPPE PFDF, it is recommended to study the Joint Ops PFDF, JOPS, and the Payload Systems Handbook (PSH) while reading this chapter of the WUPPE OPS manual.

A detailed description of operations, by display, is given in the following sections.

 

 

3.1 WAC Display: WUPPE Activation

With the exception of the DEP-active flag (line 13), and the display-allocation commands and flags (line 14), the WAC display is driven entirely by hardwired inputs and outputs, and thus may be used when the DEP is not operative (i.e. for instrument turn on or in contingency situations).

Analog-sensor outputs are displayed on the right side of the display. They are EC limit monitored as referenced in the SID list in the PFDF.

Lines 3-5: Optics temperatures (see Fig. 2.2-3 for locations). These critical temperatures are valid whenever the Temp.-Monitor Power (line 4) is on. Expected values for these are 20-25° C. The optics must not get too cold (even in non-operative conditions) to prevent condensation of contaminants on mirrors, and the spectrometer must not suffer excessive thermal changes because of the thermally-sensitive optical contact in the polarizing prisms.

Line 7: Heater power and current. These readings are valid as long as Spacelab power is on (there is a small unswitched power supply powering the sensors). The voltage is measured after the heater-power relay on line 7: it should read 0 volts with heater power off, and 23-32 volts with it on. The heater current reflects the state of the WUPPE thermostats (see section 2.2.5), between 0 and 15 Amps.

Line 8: Electronics power and current (LVPS). These readings are valid after LVPS power (line 12) is turned on. Voltage should be 24-32 Volts, and current will vary from about 5-9.6 Amps, depending on the Functional Objective (FO). It is recommended that this value be monitored closely, as it is often an indicator for occurence of non-nominal situations.

Lines 9 - 14: LVPS output voltages. Valid after LVPS power is on. They are the voltage before any enabling relays (e.g., HVPS and motor relays described on WCO display), and the values should always be near the nominal values listed before them on the display.

Lines 16 - 19: Electronics-related temperatures. Valid after LVPS power is on. The DEP temperature is read on the DEP and subsystem radiator, the LVPS temperature is measured at the LVPS nearby, and the I/F temperature is on the electronics interface box on the other radiator. They should range from -25 to +30° C during operations. The drive-ring temperature is measured on the forward-secondary drive-ring near the forward LVPS's and IMC electronics; it should read near 15-20° C.

Item Entries on the WAC display function as follows:

53/54 Temp Monitor: These turn on/off the enabling power for the optics-temperature monitors on lines 3-5. The relay state feeds back to the display in columns 21-23.

55/56 Door Latch A/B Sel: These select the redundant door-latch solenoids. This will only be necessary in case of a primary (A) solenoid failure. The feedback in column 23 reflects the DO level as detected in the instrument and is always valid.

57/58 Door Latch Unlock Power: These turn on/off power to the solenoid which unlocks the door (see section 2.2.4.8). When turned on, the latch will be pulled back in less than 1 second and the latch-microswitch feedback in column 31 will change from "LK" to "UL". If the latch does not go to UL, the power should be turned off within 15 seconds in order to prevent heating of the solenoid. The Backup-Door mechanism should not be commanded open if the latch is locked. If the DEP-controlled door mechanism is commanded open with the latch locked, an error message "DOOR LATCHED" will be sent to line 20. The latch-position indication is always valid.

59/60 Htr A/B Sel: These select the primary or redundant heater banks. This will only be necessary in case of a primary (A) heater failure. The relay is latching and will be left in the "primary" state before launch. If the redundant heater is to be activated, it is advised to turn the heater power off before switching banks, then turning it back on again.

61/62 Htr Power: These turn on/off the power to the selected heater bank. The state of this relay is reflected by the heater voltage on line 7.

63/64 DEP A/B Sel: These select the primary or redundant DEPs (both located on the DEP radiator). This will only be necessary in case of a primary DEP failure. The relay-state feedback in column 23 is valid only after LVPS power is on, and will read "B" when it is off; thus the bank state can be verified only after item 69 below is executed. The relay is latching and will be left in the "primary" state before launch. If the redundant DEP is to be activated, it is advised to turn the LVPS power off before switching banks, then turning it back on again to verify bank.

65/66 RAM A/B Sel: These are just like Items 63/64 above, except they select redundant data RAM within the selected DEP. The same limited feedback and power-down-switching sequence applies.

69/70 LVPS Power: These turn on/off the main LVPS power feeding all electronics except the heaters and door latch. When on, the LVPS voltage, current, all LVPS outputs and the remaining temperature sensors become valid. The current should read between 5.0 - 9.6 Amps, if this is not the case it is likely that an off-nominal situation has occured. The state of the relay is reflected in columns 21-23. In addition, the DEP receives an automatic reset and enters an initialization procedure during which ROM and RAM are tested, software and hardware are initialized, protocol started, and the DEP 1-Hz RAU and HRM telemetry loop are started. Within 2 seconds, the DEP-active flag will be set and will remain set as long as the DEP is functioning correctly. This flag is a hardware telltale driving a DI which must be reset at least every 2 seconds by the DEP accessing a certain address.

73 Rst DEP: This delivers a reset pulse to the DEP. It is required only in a DEP-failure contingency. The various initialization options for different reset conditions are described in section 5.8.4.

98/99 WCO/WED: These commands cause the DEP to re-allocate the second WUPPE-DEP-display buffer between the WCO and WED displays. The DEP initialization procedure will automatically allocate and load the WOB display, but not either of the alternate displays, so that the feedback flags will initially be blank. The WCO/WED item entry thereafter causes the DEP to request de-allocation of the WED/WCO display if required to free the buffer, and to request allocation and background load of the WCO/WED display. The flag for the deallocated display will immediately disappear and the flag for the allocated display will appear when the background has been loaded by the EC (about 1-20 seconds depending on MMU use).

Example: / becomes */ or /* depending on which IE was given.

74/75 Backup Door Mechanism Direction: (Note: The Primary Door Mechanism is DEP controlled and described under the WCO display.) Item 74 has the direction "open", item 75 the direction "close" the door.

76/77 Backup Door Mechanism Power: These commands control the hardwired backup-door mechanism described in section 2.2.4.8. It is operable whenever the LVPS power is on even if the DEP is inoperative, and uses only the Mtr +28V and Dtr +5V outputs. The backup door Opened/Closed indicators reflect microswitches which are independent of the indicators for the DEP-controlled door mechanism. The backup-door mechanism is operated by selecting with Items 74/75 the direction for the stepper-motor-pulse generator. Door-motor power is then enabled with Item 76 and the door will move: pulses will be applied until the microswitch sensor in the requested direction is activated. If the direction is "Open", the "Closed" indicator will immediately disappear and about 45 seconds later the "Open" indicator will come on. The pulses will be stopped and the motor power will be turned off. Item 77 then disables the motor (otherwise, an attempt to run the DEP-controlled mechanism will be counteracted by the backup mechanism). The position sensor, direction, and power indicators are not valid when LVPS power is off, and will read *, CLS, and DIS, respectively. Direction and Power will read "Closed" and "off" when the LVPS is turned on.

 

 

3.2 WCO Display: WUPPE Checkout

3.2.1 Special Procedure SPEC (SP)
3.2.2 Special Procedure ZOD/ CCTV (ZO)
3.2.3 Special Procedure APER/ FIL (AF)
3.2.4 Special Procedure SEC MTR (SM)
3.2.5 Special Procedure IMC (IM)
3.2.6 Special Procedure MEM (MY)
3.2.7 Special Procedure PARAM (PA)

WCO is a DEP display that shares a buffer with WED. To call up WCO it may be necessary to allocate it through Item 98 (see WOB display). Data on the WCO display are driven by DI, AI, DEP serial message #1 which is updated at a 1-Hz rate, and by addon messages (DDS message, recreated on the ground from GML data) from the DEP (lines 17-19). Item entries on the WCO display include both direct DO operations and DEP items, which are checked for legality against WUPPE status as described in section 2.4.1. The commands function as follows:

78/79 TV High-Voltage Power Supply: These turn on/off (by DO) the input power to the ZOD-image-tube power supply. The feedback DI reflects the state of the relay. With power supply off, TV gain on line 6 will read 0, and only background will be seen if the ZOD is scanned; with it on, it should read as in the Table "TV MAGNITUDE VALUES" in the PFDF.

80/81 Spectrometer High-Voltage Power Supply: These turn on/off (by DO) the input power to the SPD-image-tube power-supply. The feedback DI reflects the state of the relay. With power supply off, SPC gain on line 9 will read 0, and only background will be seen if the SPD is scanned; with it on, it should read as in the Table "SPECTROMETER MAGNITUDE VALUES" in the PFDF.

11 TV Z/F/DF/S (Mode) and Thr/Scl: This DEP command controls the CCTV display. It appears also on the joint JAC and JOB displays, where it functions identically. Data to be keyed in include a mandatory mode character and an optional integer valid in Field and Spectrum modes. Command feedback for the mode is via the TV-status field on line 19, which displays "ZOOM, FILD, DFLD, and SPEC" as on the joint pages, and via the CCTV picture itself. THR is the threshhold signal between black-and-white pixels in the field display; it is reset to a nominal value of 3 (12% fullscale signal for the CCD) at the beginning of each sequence. It may be adjusted up or down by factors of two by item 11: hence "Item 11 F 1" will cause stars down to 3% of fullscale to be displayed as white pixels in field mode. The field reads only 2 digits (including the + or - sign). Values as tested on the Engineering Model are 50, i.e. such numbers, if entered accidentally, will not crash the system although they are meaningless. SCL is the vertical scale used in plotting spectra; it is reset to a nominal value of 0, in which the expected signal from the planned LOG-R is plotted at half scale. It may be adjusted up or down by factors of two by item 11: hence "Item 11 S 1" will cause the current plot to be replotted at half the nominal scale.

12 TV Magnitude: This DEP/ joint command changes the ZOD sensitivity by adjusting the exposure time ("frame") and image-tube gain as shown in the PFDF. Legal values are -3 to 17. When this command is legal, the value on line 5, FRM and GAIN on line 6 (GAIN combines the tube-gate asterisk and the gain value) will change immediately and the CCTV display will brighten or darken as appropriate. If a star is acquired in zoom mode, the % SAT value will also change.

16 TEC Setpoint: This DEP command resets the DEP Thermo-Electric-Cooler control algorithm (see section 2.2.6 for TEC hardware details). When the DEP is activated, the TEC is off, and TEC setpoint is set to 0. TEMP ERR will be meaningless, TEC VOLTS = 6.2, and RAD TEMP will reflect the thermostatic control on the TEC radiator. When Item 16 is executed with non-zero setpoint, the control will enter cooldown phase, with TEC Volts = 10. The nominal setpoint value will be about -45° C. The DEP will read the Reticon temperature thermistors and calculate

               TEMP ERR = T(RET) - T(SETPOINT). 

It will be displayed as alternating every two seconds between -10 and 1/10th of its true value until the error is negative, when the DEP will automatically enter fine control. (The alternating display is the primary indication of cooldown phase). In fine mode, the temperature error will be displayed as its true value (updated once per second) and the TEC Volts and temperature error will vary with time as described in section 2.2.6. When the fine-mode control has converged to 0 error, it should not depart more than 0.1 degrees from 0 if the control is operating properly. This is required to insure good Reticon thermal-background subtraction. The fine-mode setpoint may be reset during fine-mode operation by re-executing Item 16 with a new value; control will remain in fine mode. Such a reset may be necessary if the TEC voltage is driven to its limits of 7 or 11 Volts when the TEC radiator is at its thermal extremes. The TEC is turned off by giving Item 16 with setpoint = 0: for about 5 to 10 minutes the TEC will execute a warmup algorithm indicated by alternating TEMP ERR display, then it will turn off (ERR = 0); TEC setpoint will go to zero and TEMP ERR will become meaningless.

14 Spectrometer Detector Magnitude: This DEP/ joint command changes the spectrometer sensitivity by adjusting the exposure time ("frame") and image-tube gain as shown in the PFDF. Legal values are -1 to 17. When this command is legal, the value on line 8, and FRM and GAIN on line 9 will change immediately; the FRM value will not actually take effect until an observation is started or resumed. The gate indicator on line 9 will remain on except when DEP status on line 19 is "Standby" or "On".

During observations, Reticon-signal levels are reflected in the LOG-R and % SAT values on lines 8 and 10. These are updated at every Reticon readout (every "FRM" seconds). LOG-R is the base-10 log of the total (array A+B, all pixels) number of photons/sec being detected; values should be close to the (planned) PL LOG-R for the object listed on the WOB display and marked on the spectral display by the LOG-R tickmark (see 3.7). The PFDF gives typical values of LOG-R for continuum objects whose UV magnitude is equal to the spectrometer-magnitude parameter; this value is corrected for Reticon thermal background. % SAT A,B is the percent of Reticon saturation that accumulated during the last Reticon frame, measured at the peak of the spectrum. The frame-integration time for a given stellar magnitude is chosen to keep the saturation signal as high as possible (this maximizes the dynamic range of the spectrum) without risking oversaturation (loss of data). An error message "RET SIG " is issued by ECOS and the value is show in overbright if % SAT becomes greater than 96. % SAT is the sum of Background plus Star, shown in the Table "SPECTROMETER MAGNITUDE VALUES" in the PFDF. A and B refer to the two Reticon arrays receiving different polarizations; except during certain polarimetric calibration runs, they should be comparable.

82/83 WUPPE IMC High-Voltage Power Supply: These turn on/ off (by DO) the input power to the WUPPE IMC-actuator power-supplies (note: this is the WUPPE IMCA, not the Astro IMCS, see also 2.1.3). The feedback DI reflects the state of the relay. External IMCS signals to the pitch and yaw actuators are disabled by the DEP during the ON and STB states, indicated by a value of 0 for IMC Status on line 16. IMC external signals are enabled at the beginning of a locate step LOC (unless an IMC-LOC flag is not set, and then it is enabled at the beginning of OBS) and in the IMC verification special procedure: IMC Status then becomes 1. When IMC is enabled, the external signals are compared in hardware to a threshhold register: if the threshhold is exceeded, IMC STATUS will go to 2. If this continues for more than 3 seconds, ECOS will issue an IMC EXCUR error message. The Spectrometer-image-tube gate may be turned off during such excursions, depending on an IMC-excursion-mode register (i.e. a table of values and corresponding actions). The excursion threshhold will initially be set to 5 arcseconds in both pitch and yaw, and the spectrometer gate will remain. The maximum excursion is 11 arcsecs.

17 IMC manual disable/enable toggle: ITEM 17 is used to toggle the IMC status between -1 (disabled) and the non-negative values 0,1, and 2, depending on which state the IMC is in when it is enabled. After power-up, WUPPE is prepared to accept Astro-IMCS data and to use it at appropriate times during observations. Non-negative values of the IMC status indicate that WUPPE is accepting and handling IMCS data in this fashion. The 0 status indicates that IMC data is not currently being used to move the secondary mirrors, but when an observation begins it will be. Status 1 indicates that the WUPPE-IMC actuators are actively driving the secondary mirrors. Status 2 is entered from status 1 when the IMC data indicates a pitch or yaw error that exceeds a warning threshold; that is, we have an IMC excursion. Status will return to 1 when the pitch and yaw errors return to within limits. The remaining IMC status is -1, which indicates that IMC data will be ignored and that the WUPPE image motion compensators will not be used. When IMC is enabled, the actions depend on whether the IMC locate flag is set to 1 or 0. The IMC locate flag

Item 17 toggling and IMC status

    WUPPE state             Idle       Locate       Observe    Idle
    WUPPE status            ON, STB    CUR, CUR,    OBS        STB
                                       LOC, LOC

   IMC disabled             -1         -1           -1         -1
   IMC enabled with
    IMC locate flag = 1     0          1 (or 2)     1 (or 2)   0
    IMC locate flag = 0     0          0            1 (or 2)   0

has the software operational parameter 5 and can be set in special procedure PA. The values of IMC status in the disabled and enabled states with the locate flag set or not set in various WUPPE states is summarized above.

18/19 Open/ Close Primary Door Mechanism: These DEP commands control the primary-door mechanism as described in section 2.2.4.8. Feedback is through the door-position sensors displayed on the same line: if the door is closed, an open command will cause the "Closed" indicator to go out, and the "Open" bug will come on 30 seconds later.

Example: OPN/CLS /* becomes / and then */

The Bright-Object Sensor is described in section 2.3.4; since it is outside of the door it is not affected by door motions, but it is used in decisions of whether to stop observations, causing image tubes to be gated off, or to close the door for thermal reasons.

84/85 Lamp Power: These commands control a DO which turns on/ off the Test-Lamp High-Voltage Power Supply (see section 2.3.2). The DI reflects the state of the relay. If the Door is closed when the lamp is turned on, an approximately 5-arcsecond image of TV magnitude 6 and SPD magnitude 4 will appear within 1 arcmin of the Line of Sight.

86/87 PROM Programming Power: These commands control a DO which turns on/off programming power to the EEROM memory. It is used for Starlist and program-patch loads through the "MEM" special procedure.

88/89 Monitor Card Power: These commands control a DO which turns on/off power to the RS-232/ Breakpoint Card. It is normally off and is used only for debugging contingency.

95 Shutdown: This DEP/ joint command immediately aborts the current operation, gates off detectors (gate display on lines 6 and 9 will go off), starts the door closing (OPN indicator will go out), and enters the ON state, thus returning to a condition insensitive to environments.

99 Allocate WED display: See WOB display. Since WED shares a buffer with WCO, execution of this Item from WCO will cause the DEP portion of the DDU (the Data Display Unit on the shuttle Flight Aft Deck) to go blank as it is de-allocated.

Lines 17-19. These lines are driven by "Addon" messages from the DEP. The add-ons are listed in the PFDF following the description of the WCO page as "WCO PROCEDURE ADD-ONS". There are four distinct addon-message types.

Addon-message types:

Types 1 and 2 are written when special procedures (described below) are being executed; these are displayed on lines 17 and 18 of the WCO display. Except during execution of a special procedure (DEP state STB) line 17 is a special-procedure "menu".

Type 3 is a name line, which is updated whenever a Preview or Setup command loads the preview or current sequence buffers; it occupies line 18 of WCO, WOB, and WED (it overwrites the Type 2 message on WCO when a special procedure is not active).

Type 4 is a Status line, which displays the current DEP state (the same as the Joint Status), the TV mode (the same as that message on the Joint displays), and tutorial messages ; it appears on line 19 of the WCO, WOB, and WED displays. The PFDF contains a list of "DEP LINE-19 TUTORIAL MESSAGES".

50 Run Special Procedure: This DEP command, with a two-character code as data from the special-procedure menu on the WCO display, causes the DEP to run a special procedure. It is legal in DEP states "ON" or "STB". The state is changed to STB, lines 17 and 18 are rewritten, and the items displayed on the addon become legal. In particular, Item 50 becomes an "exit special procedure" command which causes the DEP to return to its original state and the menu line to be rewritten; Item 50 is thus in effect a special-procedure toggle. The functions of Items 48, 49, 51, and 52 vary with the procedure (see following subsections). Items 48 and 49 are related to initialization and verification, and 51 and 52 are related to data display and editting. Whenever a special procedure is entered, the data on line 18 are initialized to SEL = 1 and the corresponding displayed value.

Note: It is possible to go from one special procedure directly into another one without exiting.

3.2.1 Special Procedure SPEC (SP)

This procedure is used to initialize and verify the function of the Spectrometer detector.

48 Initialize Reticon: This takes a number of very short Reticon readouts and computes analog offsets for the four parallel A/D convertors in the Reticon hardware. (This is the equivalent to the setoff command at Pine Bluff Observatory.) Hexadecimal analog-setoff numbers proper initialization. They are written into the occasional data file (see the section on the GSE). The values of the setoff numbers are temperature dependent, they go up when the temperature goes down. In general, the numbers should read between 40 and d0. A calibration of setoff numbers versus BR temperature is not currently available. When the reticon is cold, (i.e. -25°C) the setoff numbers should read

Analog-setoff numbers at -25°C

bc b0 a8 b3 b4 98 a6 a1 (1)

Item 48 may be run with the Reticon warm or cold. Upon execution, the Tutorial message "INIT RUNNING" will appear on line 19, and line 9 will show FRM = 0.2 and a % SAT value for two seconds, then FRM = 0.5 and a % SAT value for two seconds, both with tube gate off. No spectral display will be seen. About 5 seconds of calculation will follow, and the line-19 messages "INIT COMPLETE" or "INIT FAILS" will indicate the result, which is based on a comparison of the calculated offset values with an expected range.

49 Verify/ Stop Spectrometer Detector: This command puts the Spectrometer into a mode which alternates Reticon scans with a spectral display until requested to stop by reexecuting the Item. A line-19 message "VERIF RUNNING" appears throughout, and Items 48 and 50 are illegal until the mode is toggled off. Spectrometer FRM and GAIN are set by Item 14, and a Zoom display of the on-axis ZOD image is available and controlled by Items 11 and 12, as in the Observe step. The spectral display is updated after every readout, but reflects only the previous readout (it does not accumulate as in observing). LOG-R and % SAT will reflect the sum of the input spectrum and background (no background subtraction for display or LOG-R as in observing).

3.2.2 Special Procedure ZOD/ CCTV (ZO)

This procedure allows for verification of the ZOD and CCTV and for use of the ZOD as a debugging tool.

48 CCTV test pattern: This command causes the DEP to write a test pattern in the CCTV memory. The Zoom pattern is a series of grey-scale wedges, and the Field pattern is a cross hatch. Successive executions of this Item will toggle between the two modes, with the current mode shown on the TV-status field on line 19.

49 Verify/ Stop ZOD: This command puts the ZOD into a mode which runs the ZOD continuously, allowing all scan modes, "ZOOM", "FLD", and "DFLD" via Item 11. The line-19 message "SCANNING LOC (or OBS) AREA" will be displayed as long as this mode continues; it is stopped by reexecuting the command. Items 48 and 50 are illegal until the mode is toggled off; Items 51 and 52 (described below) are legal only in this mode, as indicated by the parentheses enclosing them on the display. Item 12 is used to control the ZOD magnitude as before. Scanning may be in the off-axis "Locate" area (see Item 51 below), with the Zoom centered on the nominal center of the Locate aperture, or in the "Observe" area. In the Zoom and Field modes the cursor is displayed to indicate the center of the Zoom picture; the cursor motion commands are accepted and the Zoom picture will follow (until the Zoom is forced out of range, which will give a "ZOOM LIMIT" error message).

51 Toggle Locate/ Observe ZOD scanning: This command causes scanning in ZOD-Verify mode to switch to the alternate half of the CCD. If in LOC area (illuminated by the off-axis aperture), scanning will switch to the OBS (on-axis) area, or vice versa, and the line-19 message will be updated accordingly. This is legal only in ZOD-Verification mode.

52 Re-initialize ZOD aperture locations: This command is used if it is necessary to reset the aperture locations that the DEP uses to center stars in the Locate or Observe steps. At the beginning of the mission, proper location of the apertures will be verified and the command may or may not be issued, as necessary. With a star or test-lamp image centered in the desired aperture, Item 49 is used to put the ZOD in scanning mode. The cursor is put on the image using

Table 3.2-1

Aperture Offset Table

                                 Aperture      P*      Y*    

                                      0       44      -22    
                                      1       51        0    
                                      2         0       0    
                                      3      -24      -18    
                                      4      -67      -10    
                                      5      -81       -6    
                                      6      -72      -19    
                                      7      -48       24    
                                      8      -51       64    
                                      9      -63       76    
                                     10      -60        7    
                                     11      -38      127    
                                     12      -83      127    
                                     13     -102      127    
                                     14        0        0    
                                     15        0        0    

                        * Pitch and Yaw offsets in units 1/10 pixel

the PFKs, and Item 52 is executed. A centroid is performed on the image and the results are stored as a new position for the current aperture. The acquisition marks will flash once if the object is found. If the object is not found or if the ZOD % SAT is below the warning value, the line-19 message will be "INIT FAILS", otherwise "INIT COMPLETE". The expected (pre-flight) Aperture/ Position values are given in Table 3.2-1 and are relative to aperture 2. These values are expected to be updated during during flight using a WUPPE aperture-calibration target (ID 05xx).

3.2.3 Special Procedure APER/ FIL (AF)

This procedure is used to verify and debug the Aperture and Filter Wheel mechanisms.

49 Verify Aperture/Filter Wheels: This command runs an automated exercise of the wheels. During the procedure, the line-19 message "VERIF RUNNING" will appear. First the aperture wheel (line 18 SEL = 1) is run to positions (line 18 POSN) 0, 2, 4, ... 14 then 15, 13, 11, ... 1 at about one position/second. Then the procedure is repeated for the filter wheel (SEL = 2). The procedure takes about 45 seconds. A failure will be indicated by an "APER (or FIL) OVRUN" error message, and the procedure will have to be aborted with a SHUTDN command.

51/52 Select Wheel and Position: These commands are used for debugging when it is desired to move the wheels on manual command. Item 52 moves the selected wheel to the input position, and Item 51 changes which wheel is selected.

3.2.4 Special Procedure SEC MTR (SM)

This procedure is used to initialize the secondary mirror position and for mechanism debugging.

48 Initialize Secondary mirror position: The secondary mirror is nominally aligned and focussed when the three motor-position potentiometers (section 2.1.2) are at 177, 141, and 134. Item 48 runs an automatic initialization procedure which steps the three motors simultaneously until this position is read, and resets the software variables which keep track of the mirror offset (see WOB display). This takes about 30 seconds, during which line-19 message "INIT RUNNING" is displayed. Line 18 displays the position of one of the motors; it will approach and stop at the aligned position.

51/52 Select/ Move Secondary motor: These commands are used for debugging when it is desired to move individual motors under manual control. Item 52 causes the selected motor (SEL = 1, 2, 3) to move to the input position, and Item 51 changes which motor is selected. It will be necessary to reinitialize the mirror position using Item 48 after manually moving the motors. Motion of one position bit corresponds to 103 microns, 113 motor steps, or 16.9 arcsec of offset. The motors run at 47.7 arcsec/sec or 2.8 position quants/sec.

3.2.5 Special Procedure IMC (IM)

This procedure is used to initialize the IMC actuator electronics and to verify response of the system to the external IMC-Calibrate signal.

48 Run/ Stop IMC Electronics Initialization: This procedure verifies IMC actuator function, finds the IMC actuator limits and centers the electronic offset registers by finding the extreme travel of a star image as the actuators are driven by internal signals. It is assumed that a star has been centered in the LOC aperture with IMC High Voltage on. After execution of Item 48, a Zoom scan of the star image is started and the line-19 message "ADJUST TVMAG" is displayed until the object is acquired with a ZOD % SAT > 25. If necessary, an Item 12 will increase the ZOD signal to that value, or another Item 48 will abort the procedure. When satisfied, the message will be replaced by "STOP IF NO MOTION" and a change to Field display. The actuator will then be forced to toggle every second for 20 seconds between two extreme corners approximately 25 arcseconds in both pitch and yaw, while the cursor will be placed where the DEP expects the star to go. If the star does not follow the cursor, the actuators are not functioning properly and an Item 48 will stop the procedure. The display will then return to Zoom mode centered on the initial position and line 19 will display "INIT RUNNING", indicating the final phase. Here, each IMC axis is driven until the star moves (it moves out of the acquisition box and the acquisition marks stop), then the Zoom is moved to center on the expected center of travel and the IMC is driven (at about 1 arcsec/sec) until it is acquired and crosses the center. This is done for yaw and then for pitch and the procedure is done, as indicated by the line-19 message "INIT COMPLETE". An abort via a repeated Item 48 will give an "INIT FAILED" message. Items 49 and 50 are not legal when this procedure is running.

49 Run/ Stop external IMC Calibrate verification: This assumes that an image is centered on the Zoom display. As in the above procedure a Zoom scan is started and the message "ADJUST TVMAG" is displayed until the image is acquired with ZOD % SAT > 25 or the procedure is aborted with another Item 49. When satisfied, the message will change to "RUN IMC CALIB", indicating that IMCS should be put in Calibrate Mode. As calibrate runs, the acquisition marks will follow the star in a 10 arcsec cross pattern and the pointing errors on the WOB display will indicate the IMC offset. This continues until the verification is stopped by reexecuting Item 49. Items 48 and 50 are not legal when this procedure is running.

3.2.6 Special Procedure MEM (MY)

This procedure is used for contingency patch or starlist loads and for memory testing.

48 Memory Load: There are two types of loads, variables or programs. The item 48 therefore takes the parameters VA and PG. Variables are e.g. flight software variables and operational parameters and are loaded to the data RAM (see Table 2.4-1). Programs are loaded to EEPROM and would be used for e.g. program or starlist patches, a new starlist for a new mission, or a changed parameter in all observing sequences. For a PG load, the EEPROM-programming power should be turned on. Upon execution of this command, the DEP checks to see whether the Monitor Card containing the RS-232 ground-operations link is powered. If it is, it displays the line-19 tutorial message "LOAD-RS232 (VA or PG)" and requests a file load over the RS-232 line (if this is on line, the load will proceed without interference). If the monitor is not powered, it displays "LOAD-PROTOCOL (VA or PG)" and shuts down all other EC messages while awaiting EC-protocol-load-messages (display update will cease and commands will not be accepted). The operator will then initiate the file load from MMU using keyed commands. When either load is complete (judged by an end-of-load mark in the load data), the message will change to "LOAD COMPLETE", or if there is an error, "LOAD ERROR". In either case, load mode is exited and normal operations will resume. EEPROM should then be turned off and a check of the load should be run using the memory-test commands. When the load is finished, the "checksums" provide a test of whether the load was carried out as intended. Checksums are an error-detection method in files. (Note: Checksums should be checked after DEP or starlist loads, DEP error/ crash (MP-04 in the PFDF) and in SAA monitoring.)

49/51 Run Memory test procedure: The three WUPPE-EEPROM memories (SEL = 1, 2, 3), data RAM (4), and DEP monitor ROM (5) may be checked individually by selecting the memory via Item 51 and running the check via Item 49. The test requires one second and the result is reported in the ERRORS field on line 18; it will be 0 if the memory passed and 1 if it failed. A continuous test which cycles through all 5 memories once/second may be selected by Selecting memory 0; this test runs continuously until stopped by re-executing Item 49. The SEL field will indicate which memory is currently being tested and the ERRORS field will show the number of times that memory has failed since the beginning of the test. The ERRORS field may read 1 before the start of the Memory special procedure, but will go to 0 immediatly when the memory check is started.

3.2.7 Special Procedure PARAM (PA)

51/52 Change Software Global Parameter: Certain WUPPE operational parameters may be changed based on flight experience and contingencies. These may be changed by selecting the parameter via Item 51 (to display the current value) and changing it via Item 52. The paramemters and values are listed in the Table "SOFTWARE OPERATIONAL PARAMETERS" in the PFDF. Whenever this command is issued the entire global parameter list will be down-linked so that a ground record will enable restoration of the values in the event of a power failure.

 

3.3 WOB: WUPPE Observation

WOB is a DEP display that "owns" its own buffer; that is, once allocated and loaded automatically by the initialization procedure, it remains available. Data on the WOB display are driven by DEP serial-message #1 which is updated at a 1-Hz rate, and by Addon messages from the DEP (lines 18 and 19). The commands function as follows:

98/99 WCO/ WED: allocate WCO or WED display.

1 Preview Sequence Load: This is the WUPPE-only equivalent of the joint preview-load command, but it does not cause ECAS to access the MMU object-file to obtain the sequence number and name, etc. Instead, the WUPPE-sequence number identifying the beginning of an object is entered directly. Any characters entered after the sequence number will be put in the name field. Upon entry of this command, the requested sequence and any subsequent "chained" sequences will be loaded into the preview buffer (see WED display); if it does not exist, an error message "CANT FIND SEQ" will be sent. The preview-object name will appear on the name line (Addon Type 3, line 18).

Lines 3-5 variable data: CUR SEQ refers to the sequence currently being executed; parameters on the WOB display all refer to the current sequence. SEC REM FRM, SEQ and OBJ refer to the time remaining under the current time plan. SEC REM FRM is the number of seconds until the next Reticon readout; it is 0 when the Reticon is not scanning, and decrements to zero from the planned SPC FRM time (line 9) for each frame of observing, which is determined by the Spec magnitude. SEC REM SEQ is the planned observing time remaining for the current sequence. It is set to the sequence planned time when the sequence is started, and decrements when the observe step is actually in progress. For multiple-sequence objects, after it reaches zero the next sequence will be started automatically. The last sequence in an object will decrement to zero and remain there until the Quit command terminates the object. SEC REM OBJ is the time left until the object should be left to proceed to the next object. It starts out at the Setup command as the sum of all the planned times of all sequences in the object plus the planned overhead times:


                       SEC REM OBJ = Setup-Time  +SUM(Planned-Time  (all seq)     
                                       + Locate-Time       (if LOC-flag set)   
                                       + Cursor-Time       (if CUR-flag set)  
                                       + Field-Time        (if FLD-flag set)
                                       + Mosaic-Time)      (if PIC-flag set)

The flags refer to operation flags for the sequence (see WED display), and the overhead times are operational parameters whose nominal values are given in the Table "SOFTWARE OPERATIONAL PARAMETERS" in the PFDF. When the Begin or Resume commands are given, the SEC REM OBJ is restarted with the "Time available" value given at that time; the Planned-Time values for all the sequences that remain are prorated by the ratio between the previous SEC REM OBJ and the new value less the overhead time, and the SEC REM SEQ decrements from its new value.

12, 14 TV, SPC Magnitude: These are the same as the magnitude commands on the WCO display. In columns 13-15 are the actual magnitudes, and in 18-20 are the values from the starlist for the current sequence.

Lines 9, 10 Rate data: The LOG-R spectrometer rate on line 9 gives the actual (see WCO display) and the planned value from the starlist for that parameter. Lines 9 and 10 on the right also repeat information given on the WCO display: the Reticon-Frame integration time, and the % SAT signal values for the Spectrometer A and B arrays when the Reticon is scanning, and for the ZOD Zoom image when an object is acquired.

15 Observe Aperture: The field in columns 14-15 is the actual aperture position. Except in the OBS state, the aperture will always be the acquisition aperture, Number 1. The Planned Observe aperture appears in columns 19-20; it will be set to the Planned aperture from the starlist when the sequence starts. The Planned Observe aperture may be changed at any time during the sequence, and the aperture will be moved to that position at the Begin or the Proceed command.

Line 11 Filter position: This is the actual filter position. It starts at the planned filter position when the sequence begins. It will remain there for single-filter sequences (Lyot filters 0-5) and will oscillate between that value and the next higher filter number during modulated observations (Waveplates 6-13). The time spent on one Waveplate modulation is an operational parameter (see PFDF), nominally 32 seconds (Filter swap time).

11 TV Mode: This is the same command as on the WCO display.

20 Focus: The focus position of the secondary mirror is shown, in microns, relative to the mirror-initialization position. Focus motions proceed at 300 /sec, with a one second overhead at the end for backlash removal; during this period the DEP will be in the "MIR" state. The focus may be moved manually by inputting a new position via Item 20, which is legal at all times except in DEP states SET, MIR, OBS, ON, and STB. It is also moved automatically at the beginning of each sequence, to account for thermal changes in focus and for focus differences between filters. Thermal changes are added into the focus position based on readings from the telescope-tube-strain sensors (section 2.3.4); a one-degree increase in the tube temperature should lead to a 30 increase in the focus reading (barely perceptible in the ZOD image). Sequences using the Lyot filters will set the focus 50 larger than for the waveplate filters. Manual focus updates are remembered in future automatic updates.

21, 22 Mirror Offset: The offset position of the secondary mirror is shown, in arcsec, in lines 13 and 14. The coordinate system is illustrated in Figure 3.3-1. The CCTV picture is an uninverted picture of the sky as seen by a person riding the telescope in a position initially head-up when the telescope is stowed (IPS Roll 180° ). The position of an object in the sky is defined as

Position (P,Y) = WUPPE-LOS + BIAS + OFFSET - ERROR

WUPPE-LOS is defined as the Line-of-Sight the WUPPE telescope would have if its mirror were at the mirror initialization position. ERROR is the position of the object relative to the center of the desired aperture (Pitch = up, Yaw = right as seen on the CCTV). BIAS is the mirror offset required to move an object from the LOS to the desired aperture, and OFFSET is the mirror offset required to bring an object at LOS + OFFSET to the desired aperture. This is the same as the convention used in the IMCS system. The ERROR values are calculated in the ZOD-centroid process. When the initial INIT is issued in the mission, the positions depend on the alignment achieved by the optical-cube alignment on the cruciform at KSC.

 

Figure 3.3-1 : Position of an object in the WUPPE reference frame.

The BIAS is initially derived from a table of known relative aperture positions, given nominally in Table 3.2-1 (these may be reset in Special Procedure ZOD/CCTV); it will change to the off-axis Locate aperture at the beginning of Locate, and to the correct value for the Planned Observe aperture at the Begin or Proceed commands. One goal that will be achieved early in the mission during Joint Focus and Alignment (FO-4) is a redefinition of the BIAS to the HUT line-of-sight, so that when the IPS centers an object in the HUT aperture, it will automatically be placed in the WUPPE aperture. This BIAS is updated later on in the mission by the error removed during the acquisition of each object, in order to follow collimation drifts between WUPPE and HUT or WUPPE and IPS: the ZOD-centroid Error displayed just before a Begin or a Mirror command will be effectively added to all the BIAS positions (ZOD centroiding is explained in more detail later in this section under IE 7). The OFFSET is the actual current offset of WUPPE (i.e. relative to HUT for offset pointings, like the secondary pointings) from its BIAS position, while PLN OFFSET is the planned value from the starlist for the current object and for the current step. During Locate it will be the Locate Offset, and at Begin it will become the Observe Offset. The ERROR is computed in Observe and Locate unless the ERROR is larger than 8 arcmin, which would imply that WUPPE is in a degraded mode.

Offset motions proceed at 48 arcsec/sec, with a one-second overhead at the end for backlash removal; during this period the DEP will be in the MIR state. The displayed offset is not dynamically displayed during an offset; it is set to the attained value at the end of the process. The offset may be changed manually by inputting a new position via Items 21 and 22, which is legal at all times except in DEP states SET, MIR, OBS, ON, and STB. It may also be moved manually in effect with the Mirror (IE 6) command, which adds the current centroid error into the BIAS and moves the mirror accordingly. It is moved automatically at the beginning of the Locate step and between Locate and Observe steps, to account for BIAS and possible OFFSET changes.

The following commands are WOB-display versions of the Joint-Operations commands. Below are described in detail the changes to be observed on the WOB display as a result of executing these commands:

2 Setup: Start next object. Only legal in the ON and STB states. If this command is given with the door closed and with the door not inhibited, the line-19 Message "WAITING FOR DOOR" is displayed; after manual execution of Items 18 or 19 (even if it leaves the door in its original position) the message will disappear and processing will continue. The state will change to SET, the preview object buffer (see WED display) is copied into the current object buffer, and the instrument is configured for the first sequence on the object: CUR SEQ and name become equal to PRV SEQ and name; SEC REM OBJ is updated for this object as described earlier and starts decrementing; the PLN column is updated for this sequence; and the dark data from the previous Standby mode are processed into a form usable by the spectrum-plot routine (if there are no such dark or background data, the line-19 message "NO DARK COR'N" is displayed).

3 Locate: Normally one passes automatically from the Setup into the Locate step. Item 3 allows one to return to this point; it is legal in the PAU and LOC states. In Locate the field threshhold is reset to 3 (the nominal value), the aperture is moved to the acquisition aperture (no. 1), PLN-OFFSET and BIAS are updated, the mirror is moved to the planned position (state temporarily MIR), and the scanning of the ZOD commences as the state is changed to LOC. The procedure followed in the locate step is modified from the nominal by flags which are obtained from the starlist or can also be toggled directly (see WED display).

If the NOLC-flag is set, the whole step will be skipped for this sequence.

If the PIC-flag is set, a 16 sec Mosaic picture is taken (TV = DFLD) before proceeding to acquisition.

If the FLD-flag is set, acquisition will start in Field mode; otherwise it will start in Zoom mode.

If the CURS-flag is set, the cursor will be displayed, the state will be set to CUR, and acquisition will continue as described below.

If the NOCN-flag is set, automatic centroid acquisition will not be attempted, the line-19 message "ACQ BY CURSOR ONLY" will indicate that the cursor position will be used for the acquisition position. This mode is used e.g. for diffuse or other extended objects.

When an object was acquired, the ERROR values will be updated, otherwise they will be zero. If an object was aquired by centroid in Zoom mode, the %SAT Z will be updated, and the state will change to LOC or CUR, indicating that the object has been acquired automatically.

4 Cursor Mode Toggle: During the Locate step, this command toggles between the LOC or LOC states and the CUR or CUR states. The LOC and CUR states differ from each other in the acquisition boxes that are searched: In the LOC states, the acquisition box is coincident with the size of the Zoom display (24 x 32 arcsec). In the CUR modes, the Zoom and Field acquisition boxes are both a 7-arcsec square centered on the cursor. When switching from Field to Zoom modes, the Zoom will be centered on the object acquired in Locate mode, on the cursor if it is on but there is no acquisition, and on the nominally centered position if neither.

6 Remove Error with Mirror: This command, legal in the LOC and CUR states and in the PAU state, is a manual intervention in case of large pointing errors. In the LOC and CUR states, the current value of ERROR is added to BIAS (unless the NOCN-flag is set, where it is added to OFFSET), and the secondary mirror is articulated (temporary MIR state) to the new position, centering the object in the Locate aperture. This is normally advised if a manual acquisition in Field mode results in errors greater than 30 arcsec; it brings the object into a region of the ZOD where the accumulation of geometric distortions is small. In the PAU state, it is used to recenter the object manually in the observe aperture; the ERROR value is added to BIAS and the mirror is articulated to center the object. The IE 6 is associated with two peaks in the audio volume, and shows a target "jumping" in one direction and then another direction (Figure 3.3-2) because of the mirror backlash removal.

Figure 3.3-2 : The mirror motion has two directions: one actually removes the Error, the opposite one is needed for removing the mirror backlash and therefore the target "jumps" twice.

7 Begin Observation: This command is legal in the LOC or CUR states (acquisition completed) and the PAU state, if the observation must be restarted. It is the only way to start observation, except when the NOLC-flag is set, when the DEP proceeds straight from SET into OBS. On the WOB display, the object time available must be hand-keyed (in seconds), since this information is not available from the joint ECAS. When the command is given, any ERROR from the acquisition step is added into BIAS, (or both Locate Offset and Observe Offset if NOCN-flag is set). The Status is set to OBS, and IMC signals are accepted (if not already in the Locate step). The BIAS is set to the new value for the observe aperture, the PL OFFSET is set to the value for the observe step, the secondary mirror is articulated to these new values (10 second temporary MIR state), and the observe filter is placed. The filter-observed times (WED display) and accumulated spectrum are cleared.

If the NOGD-flag (WED display) is set, the line-19 message "OBS W/O GUIDE" is displayed, and no pointing errors will be available during Observe. If it is not set, ZOD scanning during observe is now set up and a guide object is centered. If the OFFS-flag is set, the zoom scan is set for the offaxis aperture, centered on the star that was used in the Locate step. If it is not (the nominal case), guiding is set up on the Observe object through the on-axis aperture by increasing the TV magnitude by one (to allow for the splitting of the image in the on-axis beam) and moving the aperture to the acquisition position (to give a large enough hole for centering). A centroid is performed on the object and any correction is applied in a small secondary offset (approx. 1 second). If the object is not found or is not sucessfully centered after 3 attemptes, the line-20 message "GUIDE SETUP " will be issued and the DEP will enter the PAU state. The DEP will remain in this state until the proceed command is given; proceed indicates that the condition has been remedied manually, and a new guide setup will not be attempted. % SAT, Z and P,Y ERROR will be updated once per second as long as observing continues.

Actual observing now begins. The state is reset to OBS, the aperture is moved to the observe position, and the time remaining is replanned based on the time available, as described earlier. Reticon scanning is started, updating SPC FRM and SEC REM FRM and decrementing the latter. As the Reticon is read out, % SAT A,B and LOG-R will be updated. If the Lyot filters are being used, the filter will remain in place during the entire sequence. If the waveplate filters are being used, the filter will be alternated between the planned filter and the next higher filter every 16 seconds. Time observed in each filter will accumulate in the % observed display on WED. When the sequence time is exhausted, the DEP will proceed to the next sequence automatically; if the sequence is the last in the object, observing will continue until the "Quit" command is given.

                                       Pointing Error

Locate


                 Cursor          TV    NOCN        Acq.                  No Acq.    Acq. req'd?   

   Auto            N            Zoom     N   Centr. around bright-          -            Y
                                             est pixel in Zoom displ.
                                Field    N   Finds 1st pattern of white     -            -
                                             pixels (raster order) in 
                                             Zoom area
                                 -       Y           -                      -            N
                   Y            Zoom     N   Centr. around                Cursor         Y    
                                             Cursor position                
                                Field    N   Finds 1st pattern of         Cursor         N
                                             white pixels within
                                             +-4 arcsec of Cursor       
                                 -       Y          -                     Cursor         N

Observe
       
                 Cursor         State   NOGD        Acq.                 No Acq.    Acq. req'd?

   Auto            N          Guide-set   N    Centr.: Brtest in Zoom       -            Y
                                 PAU      -    Centr.: Brtest in Zoom       -            N
                   -             OBS      N    Centr.: Brtest in Zoom       -            Y
                                          Y         -                       -            N
   Manual          Y          Guide-set   N    Centr.: Around Cursor      Cursor         Y
                                 PAU      -    Centr.: Around Cursor      Cursor         N 

Figure 3.3-3 : Centroiding and the meaning of Error.

                                   Table 3.3-1

                             Locate/ Observe Modes
Flags

 NOLC        Skip locate step
 FLD         Start locate in field mode
 CURS        Manual pointing update (in locate or observe)
 NOCN        Do not centroid in locate
 PIC         Do downlink field in locate
 NOGD        Do not centroid in observe
 OFFS        Centroid on locate object in observe

Major Modes

              NOLC     FLD*    CURS*    NOCN    PIC*    NOGD    OFFS    

Locate
  Auto          N       N        N        N      -        -      -
  FLD           N       Y        Y        N      -        -      -
  NOCN          N       -        Y        Y      -        -      -
  No            Y       -        -        -      -        -      -

Observe

  Auto          -       -        N        -      -        N      N
  Manual        -       -        Y        -      -        -      N
  Noguide       -       -        N        -      -        Y      N
  Offs-guide    -       -        -        -      -        N      Y

* May be changed by IE during observation. Others must be changed in edit buffer and another Setup has to be done.

Contingency Modes

    Object too diffuse/ faint
        - locate       Edit sequence NOCN-locate (CURS/ NOCN), Setup.
        - guide        Turn down TV mag to lose aqc., recenter w/ CURS, proceed, edit
                       future seqs. NOGD.
    Spoiler star
        - locate       Turn on CURS, acquire, leave on into observe.
        - guide        Turn on CURS, acquire, IE 6, proceed, edit future seqs. NOGD.

In order to understand the WUPPE locate and observe modes, it is important to understand the algorithm that the DEP uses to find stars. This process is also called "centroiding". Centroiding can be performed with cursor off or cursor on. It is normally done in Zoom. When the cursor is off, the DEP goes to find the brightest pixel in the field and draws an 11-by-11 pixel box ( 4 square arcsec) around it (see Figure 3.3-3). The outer pixel rim is used to calculate the background. The intensity in the remaining inner 9-square-pixel box is then the original intensity minus the background. This intensity is equal to the value "ZSIG" reported on the WNG page. If ZSIG is larger than a threshhold, the object is sucessfully acquired. The DEP then calculates a first moment in Pitch and Yaw. The distance from the center of the image (which might occur at a fraction of a pixel) to the center of the desired apperture is the Error. The acquisition marks flash, the Error is updated, as well as % Sat. If ZSIG is below threshhold, the object is not acquired, Error and % Sat will show 0. If the image is very noisy, there will be a lot of photon events and the DEP will attempt multiple acquisitions. The threshhold has been set in operational parameter 29 so that this will not occur at the brightest ZOD mag (13 to 15). However, it should be anticipated that operational parameter 29 will require changing during the mission. When the cursor is on, the centroiding box is drawn around the cursor.

A summary of the Locate/ Observe modes is given in Table 3.3-1 and the following flow-chart.

Table 3.3-2

Spectrometer Feedback


% Sat A, B
    - Raw spectrometer readout, not accumulated
    - Includes dark background
    - Available after first readout
    - Always ECOS monitored <96% as guard against loss of data

LOG R
    - Spectrometer readout in log cts/ sec, not accumulated
    - During OBS, corrected for background, unless "NO DARK COR'N" tutorial message
      during Setup (i.e. insufficient dark data were collected in STB)
    - Available after first readout
    - Not ECOS monitored. Compare with PLN LOG R to judge identification of object and
      adequacy of planned exposure. Crew to advise POCC if differs by >0.3.

Displayed Spectrum
    - Accumulated A+B spectrum (also called sum display)
    - Dark corrected if LOG R is dark corrected
    - Available after first readout or 8 sec or every SPC FRM, whichever is longer,
      unless SPC FRM < 1  (no display at all)
    - LOG R tick at left of CCTV display, baseline
    - Compare with targetbook - Crew to advise POCC if it differs.
    - Polarization never displayed automatically, crew may be asked to issue IE 11 S to toggle
      to spectral difference mode. The spectrum shown will be the result of A-B/A+B projected
      in the plane of the current filter pair. No baseline, but log P tick indicated. 
      Best to reduce data on GSE immediately.   

During observing, the accumulated spectrum will be plotted every 8 seconds or every SPC FRM, whichever is longer, unless SPC FRM<1 (fast mode), when the spectrum is not displayed. The spectrometer feedback is described further in Table 3.3-2. A new spectrum plot will also be forced every time an Item 11 "S" is requested. Reticon % SAT, ZOD % SAT, and the IMC status are monitored by ECOS. Error messages (as listed in the PFDF) are issued in case of violation.

8 Pause: This command, executed during Observe, causes the current Reticon frame to be read out prematurely (it is not added into the spectrum display), Reticon scanning is stopped, and a temporary Locate-like state is entered. The state is changed to PAU, the aperture is moved back to the acquisition position, and all commands become legal. This allows an object to be refound, observe paramaters such as spectrometer magnitude and observe aperture to be changed, offset and focus to be changed, and processing to be restarted at the Locate or Begin steps.

9 Proceed: This command exits the PAU state described above. Observing is continued starting at the point following the guiding initialization. If issued from the WUPPE displays, it is necessary to enter a new time available value as data with Item 9 for the time-replanning algorithm, since this value would normally be supplied by ECAS.

Item 7 Begin vs. Item 9 Proceed

Suppose a contingency has taken you to PAU. Usually, PAU would be exited with Proceed, except

1) You wish to update the LOS, because you want to change apertures, or want to observe a new object and need a new guide setup.

2) You have been observing but were getting no or poor data on the sequence. A Begin clears the spectrum display and replans the observation based on restarting the current sequence. You might also want to use Begin if you need to change the SPC MAG, or the object was lost during OBS.

91 Quit: This command is legal during all automatic sequence operations except SET and MIR. It causes the ZOD and Reticon operations to be terminated within several seconds, and returns the instrument to the STB state. In Standby, the IMC signals are inhibited, the CCTV is set into spectrum mode, and the detectors are gated off. The ZOD is not scanned (% SAT Z = 0). The Reticon is then run for 5 seconds each in SPC FRM = 0.2 sec and 0.5 sec to collect analog bias data (% SAT A,B = approx. 2, LOG-R not set). The Reticon is then run to collect thermal background for the upcoming observation. The SPC FRM used corresponds to the preview values, i.e. from preview sequence spcmag. The SEC REM FRM reset and start decrementing. Door commands are legal during STB. Setup and Special Procedure commands get the instrument out of STB. During STB, the BOS is monitored by the DEP, and the BOP state is entered if the "Earth BOS" threshhold is exceeded; BOP differs from STB only in that a Setup command is illegal.

95 Shutdown: This command is always legal. It causes the detectors to be gated off immediately, detector scanning to stop, the door to be closed, and returns the instruments to the basic ON state.

 

 

3.4 WED: WUPPE Sequence Edit

WED is a DEP display that shares a buffer with WCO. To call up WED it may be necessary to allocate it through Item 99. Data on the WED display are driven by DEP serial message #2 which is updated at a 1-Hz rate only when WED is allocated, and by addon messages from the DEP (lines 18, 19). The addon messages are the same as those defined on the WOB display. With the exception of Item 2 (Setup, see WOB), Item entries on the WED display are all associated with sequence editting, and are DEP items which are legal in all states except OFF.

Lines 14-17: These lines summarize the condition of the sequence buffers. The first line is the sequence number in the internal starlist (1-999). The second line is the planned sequence- observation time in minutes. The five columns represent the sequences for the current object. For these sequences, the sequence times will be updated to new values every time the object is replanned at Begin and Proceed. %F0 and %F1 refer to the amount of accumulated observe time for the sequence; for single filter sequences, %F0 is the percent of the planned time that has been obtained, and for modulated sequences, %F0 and %F1 are the percentages for the two filters (assuming the sequence time is divided equally). They are updated every second while observation is actually taking place. The last five columns represent the sequences for the object being previewed. The sequence buffers are initialized to zero on power-up.

The edit Item commands function as follows:

25 Edit/ Display Sequence: Lines 3-11 refer to the sequence currently being displayed for editting. Item 25 allows one to change which sequence is being displayed. The requested sequence must be one of the sequences in the buffers. (Sequences 1 to 20 are canned, they are the most frequently used sequences for generic observing.) When an Item 25 command is given, the preview buffer, then the current buffer is searched for the requested sequence number, and the data for that sequence are displayed. If it is not found, the error message "CANT FIND SEQ" is issued. Unlike the other commands on the WED page, this command does not actually change any data in the buffers. The displayed sequence is also changed automatically in certain circumstances: If a preview buffer is being displayed when a Preview command is given, or if a current buffer is being displayed when a Setup command is given, the display is automatically changed to the sequence in the new preview buffer.

The following commands actually change data in the buffers. Only the preview buffers, and the current sequences that have not yet been executed, may be changed. If one attempts to edit a past or currently executing sequence, the error message "CANT EDIT SEQ" is issued. If an edit results in a change of the number of the first sequence in the preview buffer, the "Preview Sequence" on WOB will be updated.

26 Change Sequence: When an Item 26 "Change" command is given, the buffer that is currently being displayed is changed to the requested sequence number, which may be any sequence in the starlist, and the new starlist data are displayed on lines 3-11 and 14-15.

27 Insert Sequence: This command inserts a blank sequence (sequence number 1) into the buffer currently being displayed, and pushes the following sequences down one. The current and preview buffers are handled separately, and sequences pushed off the end of these buffers are lost. Generic sequence #1 is described in ALT-1 EDIT SEQUENCE in the PFDF. Note that you cannot directly insert a new sequence that you want: you have to call upon sequence #1 and then change its number (IE 26) or the values in it (see below).

28 Delete Sequence: This command deletes the sequence in the buffer currently being displayed, and the following sequences are moved up (separately for preview and current). The new displayed buffer will be the sequence which is moved into the currently displayed slot.

29-32 Edit Planned Magnitudes, Observe Aperture, and Filter: These commands cause the values for planned quantities to be changed in the displayed sequence buffer.

35-38 Edit Planned Offsets: These commands change the planned offset values for the Locate and Observe steps. Units are arcseconds and must be in the range 1200 (20 arcmin).

34 Edit Planned Sequence Time: This command changes the planned observation time for the displayed sequence. This value is stored internally in seconds and displayed and editted in minutes. Since the planned times are replanned based on the time available at the Begin and Proceed steps, the only effect of this command is to change the relative time to be spent on sequences in a multiple-sequence object.

39 Edit Planned Log Rate: This command changes the expected value for the spectrometer rate. This is reported on the WOB and JOB displays, and has an effect on the spectral display for the sequence during observation, which contains a scale mark indicating the planned rate. Displayed to the right of the Log-Rate is a Log-Polarization, which is also contained in the starlist parameters and is used in polarization spectral display mode. It is displayed for information only on WED, and is in units of log percent (0 for 1 percent expected polarization).

40-46 Edit Operations Flags: These commands toggle the value of the planned operations flags for the displayed sequence buffer. See WOB description for the effect of these flags. Nominal operation is always represented by a NO-flag value.

1, 2 Preview, Setup: These are the same joint commands as are described on WOB. On the WED display, a Preview will cause the requested sequence to be obtained from the starlist and displayed, and will proceed to additional sequences based on a chained sequence flag contained in the starlist. The Setup command will cause the entire Preview buffer to be copied into the current buffer. Both update the name line appropriately.

 

3.5 WNG: WUPPE Engineering

The WNG display is a ground-only display, it cannot be seen on the Shuttle Aft Deck. No IEs originate from this page. The purpose of the WNG page is to monitor engineering data that have previously been proven useful for debugging purposes.

The upper half of the WNG display gives information on various motors whose parameters follow in lines 4 to 7. The motors are the Secondary Motors (S1, S2, S3), Aperture and Filter Wheel Motors (AP, FL), and Primary and Backup Door Motors (PDR, BDR). A * under SELECT indicates that the motor is powered, a + or - sign under DIRN shows the direction of motion, PH1CUR shows a * when phase 1 out of 4 phases of a motor is activated (the * is on for 1 out of 4 sec). For the Secondary Motors, there is additional information concerning the positions of the three motors under POSN. The STRAIN readings relate to the three invar rods with LVDT sensors which reveal by how much the telescope tube has changed in length due to thermal changes. These numbers are used by the DEP to update the FOCUS for thermal changes. The value of DELTA is the sum of the STRAINs relative to the value at the last mirror initialization (special procedure SM). For the Aperture and Filter Wheel there is additional information about sensor enable/ disable under ENA/DIS. The position last read on the two wheels when ENA was on is indicated in the adjacent two fields (0 0 in the PFDF). A * appears in the {} fields next to O/T if either of the motors appear to be overheating. For the two door mechanisms, there is an Open/ Cosed indication under O/C of the form */ for open or /* for closed.

In the lower half of the WNG display there are two areas with groups of readings related to the status of the Reticon and the ZOD, and values for assorted other parameters of interest.

For the Reticon, the TEC Volts are an uncalibrated number put into the register to control the TEC supply voltage. The range of values is 0 to 255. The Broad-range thermistor reading (BR TEMP) should range from -70 to 30, and the Operating thermistor temperature (OP TEMP should range from -22 to -55. In cooldown phase of the TEC, the BR TEMP is always valid and the more finely encoded OP TEMP becomes valid when the Reticon is cold. The BR TEMP is required to overshoot by about a degree before fine mode of the cool down starts working.

For the ZOD the CURS reading indicates the Cursor position. FLINE is the first line displayed in field mode. There are two halves of the CCD, so this number is either 8 for OBS-area or 264 for LOC-area scanning. The values of STRTLINE and STRTPX correspond to the first CCD line of Zoom display and the first pixel in Zoom display, respectively. An uncalibrated ZOD signal level for objects in the acq. box is given under ZSIG.

The WUPPE Audio has been extremely useful for debugging purposes on the ground. The AUDIO field is WUPPE's "loudspeaker" in flight. The number indicates the peak value of audio each second. Changes of these values have to occur when motors are in action. On the other hand, unexpected AUDIO is the first indication of a DEP crash.

MTR CUR indicates the current drawn by any motor.

STEPS shows the steps taken by any motor during any operation.

The SAA bug comes on at the entrance to an SAA and disappears upon exit from it.

The IPS field shows a * for 1 sec when an IE 5 is issued (BIAS IPS).

The value under OCC DATA is an indication for HRM downlink of special data.

The ITM field is a log of downlink IEs or PFKs received by WUPPE.

 

 

3.6 JAC: Joint Acquisition and JOB: Joint Observation

The joint Astro display pages, JAC and JOB, are described in detail in the Joint OPS, or "JOPS" PFDF (MSFC JA-515). The JOPS PFDF contains a list of IEs and malfunction procedures relevant for the use with the joint pages. The joint pages are ECAS displays. The function of JAC and JOB compares best with the WUPPE pages WED and WOB.

Commands issued on the joint pages are sent to the instruments HUT, UIT, WUPPE, and IMCS if they have been put into the command routing. Command routing is achieved by PFKs (see Fig. 3.0-1).

The ALL key sends commands to all of the experiments in the command routing, with the following rules to be observed by the PS:

1. Do not configure ALL mode to be a single experiment, and do not include IMC in the ALL mode configuration. The only exception would be if WUPPE or UIT is the only experiment being operated using the joint pages. In this case, ALL mode should be configured to be WUPPE or UIT only.

3. The IMCS is placed into STANDBY mode if JOPS routing status is ALL or IMC only.

IEs on the joint pages take care that the corresponding IEs are send to the individual experiments depending on command routing and the command filter given in Table 3.6-1. For example, Item 1, Preview, is the same for all experiments. It takes the ID's and other relevant information of targets from the JOTF on MMU. Note that the sequence # may be different for each of the instruments, since they have their own internal sequence numberings.

 

Table 3.6-1

Joint OPS Command Filter

                        Item entry    Name       HUT    WUPPE    UIT    IMC

                            1         PREVIEW     X       X       X
                            2         SETUP (1)   X       X       X    
                            3         LOCATE      X       X
                            4         CURSOR      X       X
                            5         IPS         X       X
                            6         MIRROR      X       X
                            7         BEGIN       X       X       X     X(2)
                            8         PAUSE       X       X       X
                            9         PROCEED     X       X       X
                           10         TIME AVAIL  X       X       X
                           11         CAM MODE    X       X
                           12         CAM MAG     X       X
                           91         QUIT        X       X       X     X(3)
                           95         SHUTDN (4)  X       X       X     X

(1) For SETUP commands, IPS bias commanding is enabled.

(2) For Begin commands, IMC action depends on command routing:

(a) If routing is IMC only, STANDBY, OPERATE, and TRACK modes are commanded, and the gyro offsets are zeroed.

(b) If routing is ALL mode (IMC should not be included in ALL mode), WUPPE and UIT mirror resets are commanded.

(3) If JOPS command routing is ALL or IMC only, the IMCS is placed into STANDBY mode.

(4) A SHUTDN command is issued to all instruments independent of current command routing. When IJOP ECAS is removed, this command is automatically issued to all experiments as part of IJOP's forced est end processor. The same processor for QUIT commands is incorporated as part of the forced test end processor.

 

 

3.7 CCTV Displays and Audio

There are basically three types of CCTV displays: test patterns, images, and spectra.

In special procedure ZOD/ CCTV (see 3.2.2), the IE 48 is a toggle between two types of test patterns. The test patterns are merely number patterns written into CCTV memory to check the interface; they do not depend on the status of the ZOD or SPD detectors (i.e. if those detectors were dead, one could still bring up the test patterns). In Field mode, the test pattern is a cross hatch as illustrated below in Figure 3.7-1.

Figure 3.7-1 : Testpattern in Field mode.

In Zoom mode, the test pattern is a screen full of grey-scale wedges. This is illustrated in Figure 3.7-2.

 

 

Figure 3.7-2 : Test pattern in Zoom mode.

 

The images from the ZOD are taken with an RCA CCD of 2 x 256 lines x 320 pixels, in the on-axis and off-axis beams. The size of a pixel is 30 2 or 0.8 square arcsec. The displays in Field and Zoom modes work as follows:


Field - Identification and Acquisition

         - size of 3'.3 x 4'.4, off-axis aperture, 2 arcsec images
         - 1-bit display (hardware threshold)
         - detection 0 - 15 m
         - cursor 1 pixel by 8 pixels

Zoom - Fine pointing and Focus
         - size 32" x 24" (observing apertures as listed and displayed in PFDF)
         - 6-bit grey scale
         - cursor 1 pixel x 1 pixel


Figure 3.7-3 : Examples for target aquisition and Cursors in Field and Zoom mode.

When the PFKs are commanded to do coarse cursor motions, the blink rate of the cursor becomes much faster. The cursor flashes white on a mostly black screen and black on a mostly white screen. The cursor can also help judge the saturation of an image: saturation occurs when the image becomes as white as the cursor (or when they start "blooming" in the columns direction).

The CCTV spectral display is a graphic representation of data acquired by the intensified Reticon spectrometer detector. The Reticons are two self-scanned arrays of 1024 pixels each, 3.5 mm or 91 arcsec apart. They capture the ordinary and extraordinary beams and are also called arrays A and B. The pixels are 25 x 2500 in dimension. A pixel equals to 0.7 arcsec or 2 Å. Saturation occurs at 1000 photons/ frame. The frame times range from 0.2 sec to about 256 sec (40% background at -40° C). The display may show spectrum or polarization, refer to Table 3.3-2. The wavelength range is from 1350 to 3350 Å. On the CCTV screen, this range is split in two, showing from about 1350 to 2350 Å on the upper half and the remainder of the spectrum in the lower half (see PFDF). Hence, the spectrum display has two baselines and two log-R tickmarks.

Figure 3.7-4 : Spectrum of an object with emission lines.

A typical spectrum of a star with emission is displayed in Figure 3.7-4. The Test Lamp has a smooth spectrum, no emission or absorption lines. It looks different on the ground from what it is expected to in the vaccum of space (see Fig. 3.7-5). The half-wave polarization spectrum of a highly polarized star might look like Figure 3.7-6a, the Lyot mode would have the same amplitude of the polarized spectrum, but a frequency modulation with a frequency increasing to the red as depicted in Figure 3.7-6b. The polarization display has no baselines, but two baseline tickmarks, and two log-P tickmarks. Note that the polarization can be negative since it is the result of differencing the two arrays: A-B / A+B. The 0 tickmark shows where this expression is 0. The quarter-wave mode polarized spectrum would look similar to the half-wave mode's.

Figure 3.7-5 : A spectrum without features can be seen for the Test Lamp, the maximum corresponds roughly to the maximum of sensitivity of WUPPE. On the ground, oxygen molecules cut of the blue end of the spectrum; in orbit we expect to see a lamp feature near 1600Å.

Figure 3.7-5 a,b : Polarization of a highly polarized star in half-wave and Lyot mode (which in "real life" will be much noisier than shown here...).

Audio is expected to be "heard" (WNG page, GSE only) whenever moving parts are in action. There is also the "unexpected" audio that indicates a Dep crash. The POCC personnel should monitor audio. In particular, the absence of expected audio might be used as a debugging tool.

TABLE 3.7-1

Audio


        Event                       Description               Typical Value 

 lock/ unlock door latch            short noise                TBD(during Astro-1)
 open and close door                long and constant noise    TBD
 secondary motor special procedure  long and varying noise     TBD
 error removal with mirror          double-peaked noise        TBD
 aperture filter special procedure  long and varying noise     TBD
 focussing                          long and varying noise     TBD
 during observe, when apertures, 
 filters, and focus change          long and varying noise     TBD
 Dep crashes                        incredible noise           TBD