ACS Calibration Plans by Cycle
The calibration plan for a given HST cycle consists of several proposals designed to execute exposures like darks, biases, and flats, that are used to generate ACS superdark, superbias, and flat-field reference files. These calibration exposures are also used to monitor detector statistics, including bias, dark current, and read noise levels, as well as track CTE in the ACS/WFC, among other uses. See below for all the calibration plans executed over the lifetime of the ACS.
Cycle Summaries and Proposal Information
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Date Range
11/01/2026 - 10/31/2027
Summary
Proposal ID Proposal Title 18262 ACS CCD Stability Monitor 18263 ACS Internal CTE Monitor 18264, 18299 ACS CCD Daily Monitor 18265 ACS External CTE Monitor 18266 ACS CCD Hot Pixel Annealing 18267 ACS SBC Photometric Monitor 18268 ACS Internal Flat Fields 18269 ACS SBC Darks 18270 ACS Photometric Calibration 18271 ACS SBC MAMA Recovery 18272 ACS Post-Flash Calibration 18273 ACS/WFC Gain Monitor -
Date Range
11/01/2025 - 10/31/2026
Summary
Proposal ID Proposal Title 17975 ACS CCD Stability Monitor 17976 ACS Internal CTE Monitor 17977, 17978 ACS CCD Daily Monitor 17979 ACS External CTE Monitor 17980 ACS CCD Hot Pixel Annealing 17981 ACS SBC Photometric Monitor 17982 ACS Internal Flat Fields 17983 ACS SBC Darks 17984 ACS Photometric Calibration 17985 ACS SBC MAMA Recovery 17986 ACS Post-Flash Calibration 17987 ACS/WFC Gain Monitor 18218 Additional CTE Model Pinning 18219 ACS/SBC Internal Flat Field Monitor 18227 Effect of CTE and post-flash on extended sources -
Date Range
11/01/2024 - 10/31/2025
Summary
Proposal ID Proposal Title 17651 ACS CCD Stability Monitor 17652 ACS Internal CTE Monitor 17653, 17654, 17655 ACS CCD Daily Monitor 17656 ACS External CTE Monitor 17657 ACS CCD Hot Pixel Annealing 17658 ACS SBC Photometric Monitor 17659 ACS Internal Flat Fields 17660 ACS SBC Darks 17661 ACS Photometric Calibration 17662 ACS SBC MAMA Recovery 17663 ACS Post-Flash Calibration 17664 ACS/WFC Gain Monitor 17880 Completing the Calibration of ACS Polarimetry Modes 17895 HST/ACS Observations for Cross-Mission Flux Calibration 17931 Enhanced Pixel-based CTE Model Internal Observations -
Date Range
11/01/2023 - 10/31/2024
Summary
Proposal ID Proposal Title 17331 ACS CCD Stability Monitor 17332 ACS Internal CTE Monitor 17333, 17334, 17335 ACS CCD Daily Monitor 17336 ACS External CTE Monitor 17337 ACS CCD Hot Pixel Annealing 17338 ACS SBC Photometric Monitor 17339 ACS Internal Flat Fields 17340 ACS SBC Darks 17341 ACS Photometric Calibration 17342 ACS SBC MAMA Recovery 17343 ACS Post-Flash Calibration 17344 ACS/WFC Gain Monitor 17615 SBC Geometric Distortion Re-calibration -
Date Range
11/01/2022 - 10/31/2023
Summary
Proposal ID Proposal Title 16968 ACS CCD Stability Monitor 16969 ACS Internal CTE Monitor 16970, 16971, 16972 ACS CCD Daily Monitor 16973 ACS External CTE Monitor 16974 ACS CCD Hot Pixel Annealing 16975 ACS SBC Photometric Monitor 16976 ACS Internal Flat Fields 16977 ACS SBC Darks 16978 ACS Photometric Calibration 16979 ACS SBC MAMA Recovery 16980 ACS Post-Flash Calibration 16981 ACS/WFC Gain Monitor 17255 New CTE-Model Pinning Internal Observations 17256 Quantifying the Impact of CTE on Marginal Detections 17257 ACS/WFC Grism-Spectropolarimetry Commisioning/Calibration III 17306 ACS/SBC Darks Cycle 30 Supplemetal -
Date Range
11/01/2021 - 10/31/2022
Summary
Proposal ID Proposal Title 16519 Monitoring the Parameters of the Pixel-CTE 16520 ACS CCD Stability Monitor 16521 ACS Internal CTE Monitor 16522, 16523, 16524 ACS CCD Daily Monitor 16525 ACS External CTE Monitor 16526 ACS CCD Hot Pixel Annealing 16527 ACS SBC Photometric Monitor 16528 ACS Internal Flat Fields 16529 ACS SBC Darks 16530 ACS Photometric Calibration 16531 ACS SBC MAMA Recovery 16532 ACS Post-Flash Calibration 16533 ACS/WFC Gain Monitor 16869 Enabling Spectropolarimetry for the ACS II 16870 Effect of CTE and Post-Flash on Extended Sources 16871 Astrometric Calibration of CTE 16893 Commanding Overheads for ACS/WFC Subarrays -
Date Range
11/01/2020 - 10/31/2021
Summary
Proposal ID Proposal Title 16377, 16378, 16379 ACS CCD Daily Monitor 16380 ACS External CTE Monitor 16381 ACS Internal CTE Monitor 16382 ACS CCD Hot Pixel Annealing 16383 ACS UV Contamination Monitor 16384 ACS CCD Stability Monitor 16385 ACS Internal Flat Fields 16386 ACS SBC darks 16387 ACS Photometric calibration 16388 ACS SBC MAMA Recovery 16389 ACS Post-Flash Calibration 16390 ACS/WFC Gain Monitor 16419 ACS/WFC Darks with Reduced Exposure Time and Post-Flash 16473 Astrometric Verification of Changes in ACS/WFC 16474 Enabling Spectropolarimetry for the ACS -
Date Range
11/01/2019 - 10/31/2020
Summary
Proposal ID Proposal Title 15757, 15758, 15759 ACS CCD Daily Monitor 15760 ACS External CTE Monitor 15761 ACS Internal CTE Monitor 15762 ACS CCD Hot Pixel Annealing 15763 ACS UV Contamination Monitor 15764 ACS CCD Stability Monitor 15765 ACS Internal Flat Fields 15766 ACS SBC darks 15767 ACS Photometric calibration 15768 ACS SBC MAMA Recovery 15769 Post Flash Calibration 15770 ACS/WFC Gain Monitor 16007 Monitor and Improve the Pixel-Based CTE 16008 ACS/WFC Polarizer Calibration -
Date Range
11/01/2018 - 10/31/2019
Summary
Proposal ID Proposal Title 15519, 15520, 15521 ACS CCD Daily Monitor 15522 ACS External CTE Monitor 15523 ACS Internal CTE Monitor 15524 ACS CCD Hot Pixel Annealing 15525 ACS UV Contamination Monitor 15526 ACS CCD Stability Monitor 15527 ACS Internal Flat Fields 15528 ACS SBC darks 15529 ACS Photometric calibration 15530 ACS SBC MAMA Recovery 15531 Post Flash Calibration 15532 ACS/WFC Gain Monitor 15594 Validation of ACS/WFC Distortion, L-Flat and PSF Extraction -
Date Range
11/01/2017 - 10/31/2018
Summary
Proposal ID Proposal Title 14946-7-8 ACS CCD Daily Monitor 14949 ACS External CTE Monitor 14950 ACS Internal CTE Monitor 14951 ACS CCD Hot Pixel Annealing 14952 ACS UV Contamination Monitor 14953 ACS CCD Stability Monitor 14954 ACS Internal Flat Fields 14955 ACS SBC darks 14956 ACS Photometric calibration 14957 ACS SBC MAMA Recovery 15392 Post Flash Calibration 15393 Re-pinning the ACS/WFC Gain 15394 ACS Bandpass verification F435W 15395 Color Dependence of SBC Encircled Energy 15401 Grism Calibration 15402 Photometric Standard for ACS/SBC -
Date Range
11/01/2016 - 10/31/2017
Summary
Proposal ID Proposal Title 14506-17-18 ACS CCD Daily Monitor 14507 ACS External CTE Monitor 14508 ACS Internal CTE Monitor 14509 ACS CCD Hot Pixel Annealing 14510 ACS UV Contamination Monitor 14511 ACS CCD Stability Monitor 14512 ACS Internal Flat Fields 14513 ACS SBC darks 14863 ACS Photometric calibration 14515 ACS SBC MAMA Recovery 14514 Post Flash Calibration 14865 Repinning and Reformulation of the ACS CTE Model -
Date Range
11/01/2015 - 10/31/2016
Summary
Proposal ID Proposal Title 14395-6-7 ACS CCD Daily Monitor 14398 ACS External CTE Monitor 14399 ACS Internal CTE Monitor 14400 ACS CCD Hot Pixel Annealing 14401 ACS UV Contamination Monitor 14402 ACS CCD Stability Monitor 14403 ACS Internal Flat Fields 14404 ACS SBC darks 14405 ACS Photometric calibration 14406 ACS SBC MAMA Recovery no ID Bias Frames for subarrays 14407 ACS Polarization calibration 14408 Encircled energy curves for ACS/SBC 14409 Post flash calibration -
Date Range
11/01/2014 - 10/31/2015
Summary
Proposal ID Proposal Title 13952-3-4
ACS CCD Daily Monitor 13955
ACS External CTE Monitor 13956 ACS Internal CTE Monitor 13957 ACS CCD Hot Pixel Annealing 13958 ACS UV Contamination Monitor 13959 ACS CCD Stability Monitor 13960 ACS Internal Flat Fields 13961 ACS SBC darks 13962 ACS Photometric calibration 13963 ACS SBC MAMA Recovery no ID Bias Frames for subarrays 13964 ACS Polarization calibration 13965 Encircled energy curves for ACS/SBC 13966 Post flash calibration -
Date Range
11/01/2013 - 10/31/2014
Summary
Proposal ID Proposal Title 13589-90-91 ACS CCD Daily Monitor 13592 ACS External CTE Monitor 13593 ACS Internal CTE Monitor 13594 ACS CCD Hot Pixel Annealing 13595 ACS UV Contamination Monitor 13596 ACS CCD Stability Monitor 13597 ACS Internal Flat Fields 13598 ACS SBC darks 13599 ACS Photometric cross-cal 13600 ACS SBC MAMA Recovery 13601 Bias Frames for subarrays 13602 Bandpass variations across the FOV 13603 Post flash extended sources 13604 Post flash calibration 13605 Post flashed darks 13606 PSF support pilot program -
Date Range
11/01/2012 - 10/31/2013
Summary
Proposal ID Proposal Title 13152-3-4 ACS CCD Daily Monitor 13155 ACS External CTE Monitor 13156 ACS Internal CTE Monitor 13157 ACS CCD Hot Pixel Annealing 13158 ACS UV Contamination Monitor 13159 ACS CCD Stability Monitor 13160 ACS Internal Flat Fields 13161 ACS SBC darks 13162 ACS Photometric cross-cal 13163 ACS SBC MAMA Recovery 13164 Bias Frames for subarrays 13165 SBC Red Leaks 13166 Post flash calibration 13167 Bandpass variations across the FOV -
Date Range
1/01/2011 - 10/31/2012
Summary
Proposal ID Proposal Title 12729,82,83 CCD Daily Monitor 12730 External CTE Monitor 12731 Internal CTE Monitor 12732 CCD Hot Pixel Annealing 12733 UV Contamination Monitor 12734 CCD Stability Monitor 12735 Internal Flat Fields 12736 SBC Darks 12737 Photometric cross-cal 12738 SBC MAMA Recovery 12739 Bias Frames for Subarrays -
Date Range
11/01/2010 - 10/31/2011
Summary
Proposal ID Proposal Title 12384 CCD Daily Monitor 12385 External CTE Monitor 12386 Internal CTE Monitor 12387 CCD Hot Pixel Annealing 12388 UV Contamination Monitor 12389 CCD Stability Monitor 12390 Internal Flat Fields 12391 SBC Darks 12392 Photometric cross-cal 12393 SBC MAMA Recovery 12394 Bias Frames for Subarrays 12395 Bias Shift Calibration 12397 CCD Daily Monitor {Part 2} 12427 CCD Daily Monitor {Part 3} -
Date Range
08/01/2009 - 10/31/2010
Summary
Proposal ID Proposal Title 11465 ACS CCD monitoring and calibration for WFC 11879-995/6 CCD Daily Monitor 11880 External CTE Monitor 11881 Internal CTE Monitor 11882 CCD Hot Pixel Annealing 11886 UV Contamination Monitor 11887 CCD Stability Monitor 11888 Internal Flat Fields 11883 Earth Flats 11889 Photometric cross-cal 11884 SBC MAMA Recovery 12043 Bias Frames for subarrays 11885 SBC Darks -
The Cycle 16 calibration plan will be developed after selection of GO observations, and submission of Phase II programs. Cycle 16 calibrations will continue to be performed to support the science program. The timing of the anticipated Servicing Mission 4 may influence these calibration plans. In special circumstances proposers may wish to request additional orbits for the purpose of calibration. These can be proposed in two ways and should be for calibrations that are not likely to be in the core calibration programs. An example of a non-core calibration would be one that needs to reach precision levels well in excess of those outlined in Table 3.2 in Chapter 3 of the ACS Cycle 16 Instrument Handbook.
The first type of special calibration would simply request additional orbits within a GO program for the purpose of calibrating the science data to be obtained (see Section 4.3 of the Call for Proposals). In this case the extra calibration would only need to be justified on the basis of the expected science return of the GO's program.
The second type of special calibration would be performed as a general service to the community via Calibration Proposals (Sections 3.2.3, 3.4.2 and 3.5.3 of Call for Proposals). In this case the calibration observations should again be outside the core responsibilities of the ACS group to perform, and furthermore should be directed at supporting general enhancement of ACS capabilities with the expectation of separately negotiated deliverables if time and/or funding are granted.
Proposers interested in obtaining either type of special calibration should consult with Instrument Scientists from the ACS Group via questions to the Help Desk at least 14 days before the proposal deadline in order to ascertain if the proposed calibrations would be done at STScI in the default program.
Observations obtained for calibration programs will generally be flagged as non-proprietary.
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The Cycle 15 calibration plan has been developed and all Phase II programs submitted by November 2006. This plan includes calibrations intended to cover up to the next servicing mission, and therefore has been submitted with six extra months to June 2008. Routine calibrations continue to be performed to support the Cycle 15 science program. Results from Cycles 11, 12 and 13 have been almost fully obtained, and most of the Cycle 14 calibration observations are in hand with analyses underway.
New for Cycle 15 is the recognition that instrument characteristics may have changed slightly as a result of the Side 2 electronics switch and lowering the WFC operating temperature by 4 degrees C in July 2006. The Cycle 15 plan will provide full calibration of the ACS in this configuration.
Proposal ID Proposal Title 11041 CCD Daily Monitor 11042 CCD Daily Monitor 11043 CCD Daily Monitor 11044 External CTE Monitor 11045 Internal CTE Monitor 11046 CCD Hot Pixel Annealing 11050 UV Contamination Monitor 11051 CCD Stability Monitor 11052 Internal Flat Fields 11053 Earth Flats 11047 CCD Post-Flash Verification 11054 Photo- Spectrophot Abs. Cal 11048 SBC MAMA Recovery 11055 Color Dependent SBC flats 11049 SBC Darks (with NICMOS) 11056 Improved Sensitivity SBC Prisms 11073 Checkout of ACS Three-detector Operations 11074 Short SBC Darks -
The goal of the Cycle 14 calibration program is to optimally support science results from the community while balancing the program with available resources (HST orbits and staff analysis time). Routine calibrations such as darks are being carried forward at the proper cadence. Also, resources are being allocated for further characterization of capabilities and calibration of science observations as required in response to evolution of either performance or needs reflected in the science program as a whole.
The Cycle 14 program included special observations to improve ramp, grism and prism calibrations. The fundamental geometric distortion calibration for the SBC is being derived, and the sensitivityof QE and CTE to detector operating temperature was assessed.
At the time of writing (July 2006) programs 10736, 10737, and 10738 were slightly modified to obtain calibration data after the switch to Side 2 electronics and lowering of the WFC temperature setpoint. The following programs were added for lower level testing:
- 11005 Functional Test — MEB2 Switch
- 11006 SBC Filter Wheel Checkout
- 11007 ACS Side 2 Dump Test and Verification of ACS Memory Load
- 11008 ACS CCD Side-2 Temp Setpoint
- 11009 ACS Science Data Buffer Checks
Proposal ID Proposal Title 10722 Geometric Distortion for SBC 10729 CCD Daily Monitor 10730 External CTE Monitor 10731 UV, Narrowband Red Leak 10732 Internal CTE Monitor 10733 CCD Hot Pixel Annealing 10734 CCD Postflash Verification 10735 SBC MAMA Recovery 10736 UV Contamination Monitor 10737 CCD Stability Monitor 10738 Earth Flats 10739 Internal Flat Fields 10740 Photo-Spectrophot Abs. Cal 10741 Continuum L-flats -- Ramps 10742 Ramp, Grism Wavelengths 10743 Improved Wavelengths SBC Prism 10758 ACS CCDs Daily Monitor 10771 CTE and QE with Temperature -
The goal of the Cycle 13 calibration plan is to continue refining the definition of the ACS calibration by measuring a number of important parameters of the instrument, but with a level of resource commitment in orbits that will be lower for areas exhibiting excellent stability to date. These include the geometric distortions, L-flats, sky flats, and the quantum efficiency of the two CCD detectors. Monitoring programs followed hot pixels, the stability of bias and dark reference frames, the photometric calibration stability, and tracking the degradation of photometric performance due to CTE losses induced by the continued exposure to cosmic radiation. New observations will be aimed at testing the wavelength stability of primary filters and further refining the measure of their bandpasses, and continuing to build up polarimetric calibration. The Cycle 13 calibration plan started on October 2004
The CCD daily monitoring program will continue to provide dark and bias frames to build the corresponding bi-weekly reference files. The CTE monitoring program will continue to characterize the CCDs' CTE losses as a function of time, field crowding and background levels, and define recipes to calibrate them. Also, rough measures and monitoring of available post-flash background levels were made to allow its use in future cycles in mitigating CTE losses (these observations do not — and will not for Cycle 14 — constitute calibrations sufficient for reducing science data). Annealing of CCD hot pixels will continue as during Cycles 11 and 12, and possible contamination to the UV throughput will be monitored, although less frequently. Observations will be obtained to further define zeropoints, and to check filter bandpasses. The photometric calibration for compact or point sources with very red spectral energy distribution will be provided through observations of extreme red stars. The stability of the photometric calibration, geometrical distortions and flat fielding will also be measured and monitored through dedicated programs. Polarization calibrations will fully characterize the internal polarization of the instrument.
Proposal ID Proposal Title 10367 CCD Daily monitor 10368 External CTE Monitor 10369 Internal CTE Monitor 10370 CCD Hot Pixel Annealing 10371 CCD Postflash Verification 10372 SBC MAMA Recovery 10373 UV Contamination Monitor and SBC Dark Current 10374 ACS Photometric Stability 10375 Stability of Photometry, Geometrical Distortions and Flat Fields 10376 Internal Flats 10377 UV Earth Flats 10378 Polarization Calibrations 10389 ACS CCDs Daily Monitor 10391 Wave., Flux Prisms SBC+HRC 10453 Short Annealing Test 10720 Monochromatic PSF in the Red -
The goal of the Cycle 12 calibration plan was to complete the definition of the ACS calibration by refining the measure of a number of important parameters of the instrument. These included the geometric distortions, L-flats, sky flats, and the quantum efficiency of the two CCD detectors. Monitoring programs followed hot pixels, the stability of bias and dark reference frames, the photometric calibration stability, and tracking the degradation of photometric performance due to CTE losses induced by the continued exposure to cosmic radiation.
The Cycle 12 calibration plan started on October 2003.
The CCD daily monitoring program continued to provide dark and bias frames to build the corresponding bi-weekly reference files. Separate programs provided bias reference files for subarrays, and measured the SBC detector's dark current and stability. The CTE monitoring program characterized the CCDs' CTE losses as a function of time, field crowding and background levels, and defined recipes to calibrate them. Also, accurate measures and monitoring of available post-flash background levels were made to allow its use in future cycles in mitigating CTE losses. Annealing of CCD hot pixels continued as during Cycle 11, and possible contamination to the UV throughput was monitored. The photometric zero points of all cameras will be further refined through observations now obtained of four spectro-photometric standard stars. The photometric calibration for compact or point sources with very red spectral energy distribution was checked through observations of extreme red stars. The stability of the photometric calibration, geometrical distortions and flat fielding will also be measured and monitored through dedicated programs. Polarization calibrations were taken to fully characterize the internal polarization of the instrument. Data to support accurate wavelength measures and L-flats for the ramp filters were acquired. The plan also included accurate measures of the wavelength calibration of the grism and the prism.
Proposal ID Proposal Title 10042 CCD Daily monitor 10043 External CTE Monitor 10044 Internal CTE Monitor 10045 SBC Dark Current and Recovery 10046 CCD Hot Pixel Annealing 10047 UV Contamination Monitor 10048 Stability of Photometry, Geometrical Distortions and Flat Fields 10049 Internal Flats 10050 UV Earth Flats 10051 Bias Reference Files for Sub-arrays 10052 CCD Postflash Verification 10054 Photometric Zero Points 10055 Polarization Calibrations 10056 Calibration of Photometry of Extreme Red Sources 10057 Ramp Filter Wavelengths and L-Flats 10058 Grism/Prism Calibrations 10059 CCD Daily Monitor 10060 CCD Daily Monitor 10061 CCD Daily Monitor -
The SMOV calibration and testing period extended for roughly two months taking routine monitoring of ACS performance through April 2002. With the nominal start of Cycle 11 at July 1, 2002 and with a desire not to define the final calibration program for Cycle 11 until some flight experience from SMOV could be obtained, a decision was made to break the Cycle 11 calibration into two parts: (1) an interim program continuing routine monitoring (darks, biases) and extending characterization in areas not well covered by SMOV, and (2) the standard full program expected to start in July 2002 and run for one year. The proposal IDs and titles for the interim and standard Cycle 11 calibrations may be found below.
As for any instrument the ACS calibration plan represents a compromise between the desire to calibrate the instrument as well as possible and the availability of finite resources both in terms of primary HST orbits and in terms of human resources at STScI. The list of priorities that guided the Cycle 11 calibration planning was:
- Monitor the Health and Safety of the Instrument. This includes obtaining all data necessary to verify that the instrument is performing as planned and to insure a useful lifetime as extended as possible.
- Update and Maintain Pipeline Reference Files. Dark, biases, flat fields and sensitivities used in the pipeline calibration need to be accurate and current. Information on newly released reference files is announced via the Space Telescope Analysis Newsletter and posted on the ACS web page. The updated list of recommended reference files to be used with each data set is available through the HST Archive, and will be automatically applied when calibrated data are requested from the Archive.
- Characterization of Optical Performance. The point spread function and its variation across the field of view needs to be carefully determined as a function of wavelength.
- Characterization of detectors. This includes charge transfer effects, long wavelength fringing, hot pixel growth, etc.
The Cycle 11 calibration program was intended to most effectively balance the needs of the community for obtaining excellent science results from the instrument with the limited resources available (e.g., a nominal limit of 10% time available for calibration). Common uses of the instrument were fully calibrated.
Interim Calibrations
Proposal ID Proposal Title 9558 CCD Monitor 9559 Focus Monitor 9560 CCD Linearity Check 9561 Internal CTE Monitor 9562 Internal Flat Field Stability 9563 Photometric Stability 9564 UV Earth Flats 9565 Contamination Monitor 9566 CCD Hot Pixel Annealing 9567 SBC Dark Current 9568 Grism/Prism Calibration Standard Calibrations
Proposal ID Proposal Title 9647 CCD Daily Monitor Part I 9648 External CTE Monitor 9649 ACS internal CTE monitor 9650 CCD Hot Pixel Annealing 9651 ACS CCD Flash Calibration 9652 SBC Dark Current 9653 ACS MAMA Initial Turn-on and Anomalous Recovery Procedure 9654 ACS photometric Stability 9655 ACS Post-SMOV UV Contamination Monitor 9656 Stability of the ACS CCD: geometry, flat fielding, photometry 9657 ACS Internal Flat Field Stability 9658 UV Earth Flats 9659 Gain Dependence of Biases 9660 Earth Bright Limb Calibration 9661 ACS Polarization Calibration 9662 HRC+WFC Shutter Stability Test 9663 Focus Monitoring 9664 SDSS Primary Standards 9665 Extreme Red Stars 9666 Photometric Transformations 9667 ACS PSF Characterization 9668 ACS Coronagraph Wavelength Dependence 9669 ACS Coronagraph stability and vignetting 9670 UV and Narrow Band Filter Red Leak Check 9671 ACS Ramp Filter Check 9672 Grism/Prism Calibration 9673 CCD Daily Monitor (9674 & 9675 continue this) -
The primary goal of the SMOV3B was a timely commissioning of the HST observatory for normal science operations. For ACS this has included basic testing of the instrument functionality as well as testing/setting of the focus (internal and external), measuring the sensitivity in all filters, establishing the geometric distortion and plate scale, quantifying the point spread function for each camera, and adjusting flat fields to properly capture low-frequency variations for which ground calibrations are always difficult. Data from SMOV proposals are non proprietary and fully accessible through the HST archive. We list below the program IDs and proposal titles. Details of the Phase II programs may be found via: http://presto.stsci.edu/public/propinfo.html. Some programs are of very limited technical interest (e.g., Science data buffer check—9003), while others (e.g., WFC flat field stability—9018) collected large amounts of data in standard filters on objects of potential archival science interest.
Proposal ID Proposal Title 8947 CCD Daily Monitoring 8948 CCD CTE Test 8992 ACS ERO Program 9002 ACS Dump Test & Verification of Memory Loads 9003 ACS Science Data Buffer Check 9004 ACS Calibration Lamp Checkout Contingency 9005 CCD Functional 9006 CCD Temperature Set Point Determination 9008 ACS MAMA Initial Turnon & Anomalous Recovery Procedure 9009 ACS MAMA Fold Analysis 9010 SMOV Contamination Plan 9011 ACS to FGS Fine Alignment 9012 HRC Coronagraphic Acquisition 9013 ACS Coarse Corrector Alignment 9014 ACS Fine Corrector Alignment 9015 ACS Image Quality Verification 9016 HRC Coronagraph Repeatability 9017 ACS Image Stability Verification 9018 WFC Flat Field Stability 9019 HRC Flat Field Stability 9020 Preliminary ACS Sensitivity 9022 SBC Dark Current Measurement 9023 ACS SBC Image Quality Verification 9024 SBC Flat Field uniformity 9025 Scattered Light in Coronagraphic Obs 9026 ACS Ramp Filter Test 9027 ACS SBC Geometric Distortion Calibration 9028 CCD Geometric Distortion 9029 ACS Grism/Prism Performance Check 9031 ACS CCD hot pixel annealing 9032 ACS CCD Flash calibration 9574 Focus Monitor -
Ground calibration and testing was a prime responsibility of the ACS Investigation Definition Team (Principal Investigator Holland Ford, JHU) and was carried out at Ball Aerospace in Colorado. Thermal vacuum (and supplemental dry-nitrogen environment) testing in which orbital conditions were simulated was conducted pre-launch at Goddard Space Flight Center. Filter transmission curves, and detector quantum efficiency curves, were derived at GSFC and JHU. These tests characterized the basic properties of the optics, the detectors, and the mechanisms. During ground calibration the highest priority was given to those measurements essential to establish that instrument design specs were being met, and to those measurements that could not be obtained on-orbit. Most of the non-unique ground test data were superseded by on-orbit measurements as part of the STScI Cycle 11 calibration plan. Successive cycles of the calibration program both maintain routine calibrations (such as providing darks and biases and tracking evolving CTE) and also brings maturity to determinations of the overall QE and low-frequency flat fields.
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