Exposure Coordinator
Table of Contents
FITS Assembler
Introduction
The Exposure Coordinator has the role of ensuring that all of the exposures are taken that need to be taken and in the correct order.
Camera and Detector Definition
The coordinator will have to command up to six different detector systems. Each system has its own independent detector controller which will have a unique dispatcher.
Camera and Detector System | Dispatcher |
|---|---|
Green Archon | kpfgreen - Archon |
Red Archon | kpfred - Archon |
Exposure meter | |
Ca H&K Spectrometer | kpf_hk - Ca H&K detector |
Guider | kpfguide - Guider |
Solar Radiometer |
|
Because each will have a unique, or almost unique (the red and green Archon’s will be similar), dispatcher and detector system, each will require a custom list of keywords to control. Each detector has a different role in the science requirements for the instrument. Therefore, it will be critical that the science requirements be fulfilled by the coordinator.
Because of the current status of the solar radiometer, it will not be mentioned for the rest of the current document.
Operational Modes
There is a full list of operational modes for the instrument as a whole in the
KPF Operational Modes Spreadsheet
The table below lists the different modes from the perspective of the detector systems. The key is whether or not the data are flux limited by the exposure meter, and thus synced to that system, or are timed exposures. For the Green and Red detector systems, the timing of exposure meter is critical. Synced exposures are synced to the flux limit setting of the exposure meter. When the limit is crossed, the exposures are ended. For all other exposures, the exposure is ended after a fixed time.
The Level 0 FITS file requires a fixed number of header data units, this can be seen in the FITS Assembler description
Because the requirement on the number of the header data units, each detector system may well be involved in the data taking process even if the camera and detector are not illuminated.
Mode | Green | Red | Exposure Meter | Ca H&K | Guider |
|---|---|---|---|---|---|
Calibration | Timed exposure | Timed exposure | Timed exposure1 | Timed exposure2 | Off |
Science | Synced | Synced | Flux limited | Synced | Synced |
Science - timed exposure | Timed exposure | Timed exposure | Timed exposure | Timed exposure | Synced |
1 None of the calibrations list the exposure meter, thus this could be a dark, bias or an empty frame.
2 Not all calibrations will use the Ca H&K spectrometer. As with the exposure meter, the frames will be either darks, bias frames, or empty.
Software Actions
Action | Notes | |
|---|---|---|
| 1 | Increment Observation ID | The Observation ID is a unique integer for each set of exposures. This is used to find the appropriate FITS components for the final level 0 FITS multi-extension file. This incrementing should be done at the end of all of the current exposures. |
| 2 | Set Exposure Time | This is the maximum exposure time, regardless of the mode. |
| 3 | Exposure limited Mode | Set the mode to sync to the exposure limits set in the exposure meter dispatcher. |
| 4 | Set camera / detector combinations |
|
| 5 | Dark / Bias | Set the shutters to be open or closed for the exposure. |
| 6 | Assemble FITS file | At the end of the exposure, each of the different detector systems will produce and write to hard disk separate FITS files. Each file will contain in the name and in the header the observation ID. The FITS assembler will use the observation ID to … um … assemble the FITS file. |
| 7 | Compile FITS header keywords | The final FITS image will have, in its primary HDU, a number of keywords that are generic to the exposure. These include telescope (DCS) keywords as well as details of the instrument. The individual sub-elements will have keywords that relate to the individual detector services. |
Basic Service Keywords
Keyword | Value | Type |
|---|---|---|
EXPLIM | Timed / Flux limited Whether the exposures will be flux limited by the exposure meter or set by the timer. | Boolean |
DARK | True / False Whether or not the shutters will open for the exposure. | Boolean |
OBSID | Integer value of the most recent exposure, always increments. | Integer - not writeable |
EXPOSE | True / False Starts an exposure. Note timing of various detector systems will be managed by the appropriate dispatcher. | Boolean |
Operational Modes Expressed As Keywords
The KPF Operational Modes Spreadsheet describes the complete set of configurations in which KPF will be operated, whether for engineering, calibration, acquisition, or science exposures. The spreadsheet identifies 28 modes, and includes approximately 40 items that can be configured for each mode. Viewed as a big state table, this is a daunting ~1200 entries.
The following tables re-express those configurations as keywords, and groups them together in smaller sets that can be more easily managed by a “configurator”.
Engineering Modes
E1 Source Intensity Check
E2 Fiber-Telescope Align. - Science
E3 Fiber-Telescope Alignment - Sky
E4 Fiber-Telescope Alignment - Exp. M.
E5 Fiber-Telescope Alignment - Ca HK
E6 Fiber-Telescope Alignment - All
E7 Cool Down Green CCD
E8 Cool Down Red CCD
E9 Warm Up Green CCD
E10 Warm Up Red CCD
E11 Set Green Cold Head PID
E12 Set Red Cold Head PID
Operational Mode | Keyword/Value | Comments |
|---|---|---|
E1 – E12 | kpfmot.AGITATOR=Stopped | Turn off agitator motor power. Leave on thermal telemetry. |
| kpfexpose.SRC_SHUTTERS=none kpfexpose.TIMED_SHUTTERS=none | In most cases, shutter state doesn't matter. However, we always specify all shutters closed so that this is an in-common setting. |
| kpfpower.XXXXXX=Off | All lamps off. See keyword sets, below |
| kpfmot.CALDIODE=Home | Intensity monitor state doesn’t matter; we choose out of beam (Home location) for consistency. |
E1 | FIU acquisition with ACAM | What does this mean in keywords? |
| kpfmot.CALDIODE=Boresight | Intensity monitor: in beam |
| kpfmet.{AVG,NAVG,FILTER,RANGE,UNITS,WAVE,ZERO} = ... | Intensity Monitor: at this writing, I don't know the intensity monitor settings. |
| Cal unit: cycled through each position. | This will be a scripted action. Position doesn’t matter in configurator. |
| kpfXXX.XXXX=On | Appropriate lamps on. See keyword sets, below Lamps must be warmed up. The lamps service should include the time since each lamp has been turned on. (Q: do we also keep a total time per lamp, resetting when the lamp is replaced?) |
E2-E6 | FIU in Fiber Alignment mode | See keyword sets, below |
E2 | Science Fiber back illuminator on, others off | See keyword sets, below |
E3 | Sky Fiber back illuminator on, others off. | See keyword sets, below |
E4 | Exp Meter back illuminator on, others off. | See keyword sets, below |
E5 | Ca HK back illuminator on, others off. | See keyword sets, below |
E6 | All back illuminators on. | See keyword sets, below |
Calibration Modes
C1 Calibration on Science Only
C2 Calibration on Sky Only
C3 Calibration on Simut. Cal Only
C4 Calibration on all fibers
C5 Wide Flat
C6 Bias Frame
C7 Dark Frame
Operational Mode | Keyword/Value | Comments |
|---|---|---|
C1-C7 | kpfexpose.EXPOSURE=x.x | maybe separate into two keywords: EXPTIME=target time, and EXPOSURE=running time? |
C1-C3, C5-C7 | kpfexpose.TRIG_TARG=Green,Red,Ca_HK |
|
C4 | kpfexpose.TRIG_TARG=Green,Red |
|
C1-C5 | lamps warmed up |
|
C1-C4 | kpfmot.CALSOURCE=name |
|
| kpfmot.ND1=… |
|
| kpfmot.ND2=… |
|
| beamsplitter compensator in use |
|
| FIU in Calibration mode |
|
C1 | kpfexpose.TIMED_TARG=Scrambler |
|
| kpfexpose.SRC_SHUTTERS=SciSelect |
|
C2 | kpfexpose.TIMED_TARG=Scrambler |
|
| kpfexpose.SRC_SHUTTERS=SciSelect |
|
C3-C4 | kpfexpose.TIMED_TARG=SimulCal |
|
| mirror compensator in use |
|
C4 | kpfexpose.TIMED_TARG=Scrambler |
|
| kpfexpose.SRC_SHUTTERS=SciSelect |
|
C5-C7 | kpfmot.AGITATOR=Stopped |
|
| FIU not in use |
|
C5 | kpfmot.FF_FIBERPOS=f/# |
|
| kpfmot.<somefilterwheel>=… |
|
|
|
|
Acquisition Modes
A1 Acquisition with ACAM
A2 Acq. with FIU Tip/Tilt Camera
Operational Mode | Keyword/Value | Comments |
|---|---|---|
|
|
|
|
|
|
Observation Modes
O1 Primary Observation Mode.
O2 Star on science, sky on sky, simult. cal shuttered.
O3 Star on science, others shuttered
O4 Star on sky, others shuttered
O5 Sky on sky, others shuttered
O6 Sky on both science and sky
O7 Ca HK only (timed exposure on-sky)
O8 Ca HK only (timed exposure calibration)
Operational Mode | Keyword/Value | Comments |
|---|---|---|
O1-O8 | All back-illuminators off | See keyword sets, below |
| FIU mode = Observing | See keyword sets, below |
| kpfexpose.TIMED_TARG=Ca_HK |
|
| kpfmot.caldiode=Home |
|
| FF source=Off | See keyword sets, below |
|
| Configuration specifies Intensity Monitor is off. Is this a physical setting with keywords, or just a state of mind, so to speak? |
O1-O6 | kpfstate.AGITATOR=Running | Here, I assume a kpfstate service that implements AGITATOR=On as a single keyword, instead of requiring the configurator to set all the corresponding kpfmot keywords. |
| kpfexpose.TRIG_TARG=Green,Red,Ca_HK,ExpMeter |
|
|
| For purposes of this discussion, I assume there is a 'kpfexpose' service The writing below implies that kpfexpose copies the EXPTIME |
O1 | kpfexpose.TIMED_TARG=Scrambler,SimulCal,Ca_HK |
|
| kpfcal.CALSOURCE=<userspecified> | Octagon position. |
O2 | kpfexpose.TIMED_TARG=Scrambler,Ca_HK |
|
| kpfexpose.SRC_SHUTTERS=SciSelect,SkySelect |
|
| kpfexpose.OBSTYPE=<something> | Something indicates observation mode, but with a better name than O2, O3, … |
| kpfexpose.TGT_MAGNITUDE=x.x |
|
| kpfexpose.TGT_SPECTRAL_TYPE=x.x |
|
| kpfexpose.EM_THRESHOLD |
|
| kpfexpose.EXPTIME=cutofftime |
|
O3 |
|
|
| kpfexpose.TIMED_TARG=Scrambler,Ca_HK |
|
| kpfexpose.SRC_SHUTTERS=SciSelect |
|
| kpfexpose.OBSTYPE=<something> | Something indicates observation mode, but with a better name than O1, O2, … |
| kpfexpose.TGT_MAGNITUDE=x.x |
|
| kpfexpose.TGT_SPECTRAL_TYPE=x.x |
|
| kpfexpose.EM_THRESHOLD |
|
| kpfexpose.EXPTIME=cutofftime |
|
O4 |
|
|
| kpfexpose.TIMED_TARG=Scrambler,Ca_HK |
|
| kpfexpose.SRC_SHUTTERS=SkySelect |
|
| kpfexpose.OBSTYPE=<something> | Something indicates observation mode, but with a better name than O2, O3, … |
| kpfexpose.EM_THRESHOLD |
|
| kpfexpose.EXPTIME=cutofftime |
|
O5 |
|
|
| kpfexpose.TIMED_TARG=Scrambler,Ca_HK |
|
| kpfexpose.SRC_SHUTTERS=SkySelect |
|
| kpfexpose.OBSTYPE=<something> | Something indicates observation mode, but with a better name than O2, O3, … |
| kpfexpose.EM_THRESHOLD |
|
| kpfexpose.EXPTIME=cutofftime |
|
O6 |
|
|
| kpfexpose.TIMED_TARG=Scrambler,Ca_HK |
|
| kpfexpose.SRC_SHUTTERS=SkySelect |
|
| kpfexpose.OBSTYPE=<something> | Something indicates observation mode, but with a better name than O2, O3, … |
| kpfexpose.TGT_MAGNITUDE=x.x |
|
| kpfexpose.TGT_SPECTRAL_TYPE=x.x |
|
| kpfexpose.EM_THRESHOLD |
|
| kpfexpose.EXPTIME=cutofftime |
|
O7-O8 |
|
|
| kpfstate.AGITATOR=Stopped |
|
| kpfexpose.OBSTYPE=<something> | Something indicates observation mode, but with a better name than O2, O3, … |
| kpfexpose.EM_THRESHOLD=-1 | or whatever indicates no exposure meter |
| kpfexpose.EXPTIME=x.x |
|
O8 |
|
|
| kpfexpose.OBSTYPE=<something> | Something indicates observation mode, but with a better name than O2, O3, … |
| kpfexpose.EM_THRESHOLD=-1 | or whatever indicates no exposure meter |
| kpfexpose.EXPTIME=x.x |
|
| FIU mode = Calibration | Service/keywords are ??? |
Keyword Sets
These groups of keywords are used in the tables above:
Back-illuminator keywords
As of 2022 Apr 6, known back-illuminator controls are:
kpfpower.OUTLET_AUX2_7 = Science Back-Illuminator
kpfpower.OUTLET_AUX2_8 = Sky Back-Illuminator
x.x = Exp Meter back-illuminator
x.x = Ca HK back-illuminator
Calibration Lamp power, Intensity keywords
OUTLET_CAL2_2 = Brdbnd Source
OUTLET_CAL2_5 = ThAr Gold
OUTLET_CAL2_6 = ThAr Daily
OUTLET_CAL2_7 = U Gold
OUTLET_CAL2_8 = U Daily
OUTLET_CAL3_1 = Cal Unit Int. Mon.
OUTLET_CAL3_2 = Cal Lntrx FF FW and Intens Mon
OUTLET_CAL4_2 = Flat Field Brdband Source
FIU control keywords