How to prepare an OPE file for Hyper Suprime-Cam

Index




1. What is an OPE file?

Observations of Subaru Telescope are conducted by executing script files called 'OPE file (Observation Procedure Execute file; but often called OPEration file)'. Observers are requested to prepare the OPE file describing the sequence of your observing tasks prior to your run. An OPE file consists of information on your targets and individual operating commands such as target acquisition, exposing, focusing, filter change, etc. Please prepare for your OPE files and send them to the Support Astronomer (SA) by e-mail. On the observing night, SA and telescope operator will load your OPE file onto the observation control system and perform the observation by following your requests.

Each individual command will be executed by SA and telescope operator on a line-by-line basis. Since operators can choose any command line to execute in your OPE file and you may also edit and modify the OPE file at the summit, command lines do not have to be sorted exactly in the order of your observation plan. However, if you write down command lines in a sorted order with reasonable comment, it would be helpful for SA to understand your intent correctly and to prevent misoperation.

You may include all the targets in one OPE file. However, it would be a good idea to separate your OPE file into reasonably small files especially by each night in the case you awarded two or more nights and have a lot of targets with multiple filters/modes to observe.

Template OPE file

The template OPE file can be downloaded from here. Please follow this template file and the description below to prepare your OPE file.

2. Structure of an OPE file

An OPE file is composed of three parts. All parts should be included in the OPE file.

  1. HEADER
    • Described between <HEADER> and </HEADER>
    • Information on the file name and observing date and time
    • The information listed here does not have to be the exact amount.
  2. PARAMETER_LIST
    • Described between <PARAMETER_LIST> and </PARAMETER_LIST>
    • Several preset parameters (e.g., $DEF_TOOLS) are defined here. Please do not modify or remove them.
    • Your target list and parameters which can be referred to in the COMMAND part (see below) are defined here.
    • You can also define object names (written into fits header), coordinates, position angle of your target fields.
  3. COMMAND
    • Described between <COMMAND> and </COMMAND>
    • Commands for operating the instrument and the telescope are listed here.
    • One line contains one command.


3. Detailed description of PARAMETER_LIST section

3.1. Object list

Example NGC77145=OBJECT="NGC7714/7715" RA=233618.320 DEC=+020921.28 EQUINOX=2000.0
L1551=OBJECT="L1551" RA=043130.000 DEC=+181000.00 EQUINOX=2000.0
NGC6822=OBJECT="NGC6822" RA=+194456.000 DEC=-144806.00 EQUINOX=2000.0
NGC4038_39=OBJECT="NGC4038_39" RA=120201.250 DEC=-184554.00 EQUINOX=2000.0
NGC4826=OBJECT="NGC4826" RA=125644.100 DEC=+214634.94 EQUINOX=2000.0
M20=OBJECT="M20" RA=180222.100 DEC=-225548.00 EQUINOX=2000.0
M51=OBJECT="M51" RA=132955.000 DEC=+471855.00 EQUINOX=2000.0
SA107=OBJECT="SA107" RA=153904.500 DEC=-001400.00 EQUINOX=2000.0



3.2. Non-sidereal tracking

Example NEO1=OBJECT="NEO 1" FILE="08 20001231neo1.eph"



4. Detailed description of COMMAND section

4.1. Calibration frames

4.1.1. Bias, Dark — GetBias, GetDark —

Example GetBias $DEF_IMAGE NUMBER=10
GetDark $DEF_IMAGE EXPTIME=300 NUMBER=5



4.1.2. Flat — SetupDomeflat / GetDomeFlat / ShutdownDomeFlat —

Example SetupDomeFlat $DEF_TOOLS SETUP=SETUP Z=3.75 INSROT_POS=0 LAMP=4X10W VOLT=4.00 AMP=5.10

GetDomeFlat $DEF_IMAGE EXPTIME=17 Filter="HSC-r2"
GetDomeFlat $DEF_IMAGE EXPTIME=17 Filter="HSC-r2" NUMBER=9

ShutdownDomeFlat $DEF_CMNTOOL



4.1.3. Standard Stars — SetupField / GetStandard —

Example SetupField $DEF_IMAGE $SA107 OFFSET_RA=40 OFFSET_DEC=90 FILTER="HSC-r2" INSROT_PA=-90
GetStandard $DEF_IMAGE $SA107 EXPTIME=5 DELTA_Z=0.4 OFFSET_RA=40 OFFSET_DEC=90 FILTER="HSC-r2" INSROT_PA=-90



4.2. Main Exposures

4.2.1. Single-shot mode — SetupField / GetObject with $DEF_IMAGE / $DEF_IMAGE_VGW —

Example 1. with open-tracking
SetupField $DEF_IMAGE $NGC77145 OFFSET_RA=0 OFFSET_DEC=0 FILTER="HSC-r2" INSROT_PA=0
GetObject $DEF_IMAGE $NGC77145 EXPTIME=240 OFFSET_RA=0 OFFSET_DEC=0 FILTER="HSC-r2" INSROT_PA=0

2. with auto-guiding
SetupField $DEF_IMAGE_VGW $NGC6822 OFFSET_RA=0 OFFSET_DEC=0 GOODMAG=14.5 AG_EXP=0.2 AG_AREA=SINGLE SELECT_MODE=SEMIAUTO Filter="HSC-r2" INSROT_PA=0
GetObject $DEF_IMAGE_VGW $NGC6822 EXPTIME=360 OFFSET_RA=0 OFFSET_DEC=0 GOODMAG=14.5 AG_EXP=0.2 AG_AREA=SINGLE SELECT_MODE=SEMIAUTO Filter="HSC-r2" INSROT_PA=0



4.2.2. Five-shot mode with dithering — SetupField / GetObject with $DEF_IMAGE5 / $DEF_IMAGE5_VGW —

Example 1. with open-tracking
SetupField $DEF_IMAGE5 $L1551 DITH_RA=120 DITH_DEC=120 OFFSET_RA=0 OFFSET_DEC=0 Filter="HSC-r2" INSROT_PA=0
GetObject $DEF_IMAGE5 $L1551 DITH_RA=120 DITH_DEC=120 EXPTIME=240 OFFSET_RA=0 OFFSET_DEC=0 Filter="HSC-r2" INSROT_PA=0

2. with auto-guiding
SetupField $DEF_IMAGE5_VGW $NGC4038_39 OFFSET_RA=0 OFFSET_DEC=0 DITH_RA=120 DITH_DEC=120 GOODMAG=14.5 AG_EXP=0.2 SELECT_MODE=SEMIAUTO Filter="HSC-r2" INSROT_PA=0
GetObject $DEF_IMAGE5_VGW $NGC4038_39 EXPTIME=360 OFFSET_RA=0 OFFSET_DEC=0 DITH_RA=120 DITH_DEC=120 GOODMAG=14.5 AG_EXP=0.2 SELECT_MODE=SEMIAUTO Filter="HSC-r2" INSROT_PA=0



4.2.3. N-shot mode with dithering — SetupField / GetObject with $DEF_IMAGEN / $DEF_IMAGEN_VGW —

Example 1. with open-tracking
SetupField $DEF_IMAGEN $L1551 OFFSET_RA=0 OFFSET_DEC=0 NDITH=3 RDITH=120 TDITH=15 Filter="HSC-r2" INSROT_PA=0
GetObject $DEF_IMAGEN $L1551 OFFSET_RA=0 OFFSET_DEC=0 EXPTIME=240 NDITH=3 RDITH=120 TDITH=15 Filter="HSC-r2" INSROT_PA=0

2. with auto-guiding
SetupField $DEF_IMAGEN_VGW $NGC4038_39 OFFSET_RA=0 OFFSET_DEC=0 NDITH=3 RDITH=120 TDITH=15 GOODMAG=14.5 AG_EXP=0.2 SELECT_MODE=SEMIAUTO Filter="HSC-r2" INSROT_PA=0
GetObject $DEF_IMAGEN_VGW $NGC4038_39 EXPTIME=360 OFFSET_RA=0 OFFSET_DEC=0 NDITH=3 RDITH=120 TDITH=15 GOODMAG=14.5 AG_EXP=0.2 SELECT_MODE=SEMIAUTO Filter="HSC-r2" INSROT_PA=0



4.3. Other operations

4.3.1. Focusing — FOCUSOBE —

Example FOCUSOBE $DEF_IMAGE $NGC77145 EXPTIME=10 Z=3.45 DELTA_Z=0.05 DELTA_DEC=5 Filter="HSC-r2" INSROT_PA=0



4.3.2. Filter exchange — FilterChange1, FilterChange2—

Example FilterChange1 $DEF_TOOLS FILTER="HSC-r2"
FilterChange2 $DEF_TOOLS FILTER="HSC-r2" MIRROR=CLOSE



5. Requirements and Recommendations

When we proceed your HSC observation, we would like to ask you some requirements and recommendations listed below, which may take some observation time from you.

Requirements

  1. Take 10 or more dome flats in each band at least once per HSC observing run
    1. Use the same configuration for each filter (appropriate lamp voltage, current, and instrument rotator angle should be 0)
    2. Keep the dome flat lamp on for 10 min before starting exposures for warm up
    3. To avoid light leak from outside, dome flats should be taken 30 min after the sunset/before the sunrise
  2. Take a shot of 30s exposure for photometric calibration*
    1. Every time after filter change
    2. At least three times per night: at the beginning, middle, and end of the night (can be shared with 2-i.)
    3. When you take only long exposures (>=2min/shot), take a 30s exposure on at least one of the fields according to 2-i. and 2-ii.

      *As the Pan-STARRS1 catalog is available in HSC pipeline from 2017/2, calibration frame does not have to be obtained with the SDSS fields.

  3. If you take short exposures (<= 60s) continuously more than 20 shots, the on-site analysis system may be stopped by the SA to avoid the stall of the system. You may continue observation but information from the on-site analysis system will not be available. When you restart the long exposure (> 60s), on-site analysis system will be restarted.

Recommendations

  1. Take five or more bias frames at the beginning and end of each night
  2. In small dither, use dither steps of r > ~120 arcsec for the IMAG_N mode, and r > ~60 arcsec for the IMAG5 mode.
  3. Continuous short exposures (< 3s) more than 20 shots should be strongly discouraged because it would cause a data transfer stall.


6. Other useful information

Grammatical tips for OPE files


Overheads regarding various actions


Tools and tips


OPE file Editor (hoe)