12811( 5) - 04-Jun-2012 12:57:51 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12811 Version: 5 Check-in Time: 04-Jun-2012 12:57:51 STScI Edit Number: 0 Title CCD ACS Postflash Calibration ------------------------------------------------------------------------------------ Type Cycle CAL/ACS 19 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Marco Chiaberge Space Telescope Science Institute - ESA CoI: Dr. Linda J. Smith Space Telescope Science Institute - ESA N CoI: Dr. Jay Anderson Space Telescope Science Institute N CoI: Dr. David A. Golimowski Space Telescope Science Institute N CoI: Mr. Thomas Wheeler Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract This activity provides a set of CCD FLASH exposure reference images for each current level/shutter-side combination, for the FLASH LED on the instrument side currently in use (one LED per instrument side). It also tests linearity by exploring a wide range of flash "on" times and current settings. Short-term repeatability is also tested at the shortest FLASH exposure times that are expected to be used (2.0 sec, LOW LED current setting). ------------------------------------------------------------------------------------ Observations Description ------------------------ Internal FLASH exposures are obtained for each (LOW, MID, HIGH) LED current setting, and for each side of the shutter. The shutter is moved by inserting short internal cal lamp exposures between FLASH exposures. Two short (2 s) FLASH exposures are also obtained without any intervening configuration change to test short-term repeatability. The program includes the same exposure sequences that were taken as part of the Cycle 15 Calibration program (11047) to check for any temporal changes in the postflash performance. In addition, we use different flash "on" times (FLASHEXP) in combination with different current levels (FLASHCUR) to explore a wide range of background levels and test linearity. The program specifically focuses on exploring low background levels (down to ~20 e-) which will be recommended to users to avoid pathological CTE losses. All of the dark images have a total exposure time of 400.5s (exptime + flashexp = 400.5s). This allows us to study the distribution and the characteristics of hot pixels in presence of a wide range of background levels. The total exposure time is the same as for the Cycle 15 images, for which flashexp = 400s and exptime = 0.5s were used to allow for direct comparison with previous data. Summary of the exposures: 4x 400.5s DARKS LOW 400s 2x HIGH 400s (both sides of the shutter are checked during the same orbit) 12811( 5) - 04-Jun-2012 12:57:51 - [ 2] 2x MEDIUM 400s (to test for repeatability at high S/N) MEDIUM 2s MEDIUM 40s LOW 40s LOW 16s LOW 4s 3x LOW 2s (to test for short term repeatability at the lowest level) Real Time Justification ----------------------- Calibration Justification ------------------------- The FLASH capability has not been used to date, but it will become useful in the near future to raise the background level for observations in which the CTE losses are pathological and the pixel-CTE correction is not reliable. This program demonstrates the FLASH functionality vs. specification and monitors possible changes in LED output levels to assist in planning of its eventual use. Additional Comments ------------------- ------------------------------------------------------------------------------------ 12811( 5) - 04-Jun-2012 12:57:51 - [ 3] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: 2x 400s Darks to be taken before the postflash test Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, PAREXP=NONE 2 400.5 S ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 ACS/WFC ACCUM WFC DEF none none 1 none 1 N/A DARK 1 ACS/WFC ACCUM WFC DEF none none 2 none 1 N/A 12811( 5) - 04-Jun-2012 12:57:51 - [ 4] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: 2x 400s darks to be taken before the postflash test Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, PAREXP=NONE 2 400.5 S ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 ACS/WFC ACCUM WFC DEF none none 1 none 1 N/A DARK 1 ACS/WFC ACCUM WFC DEF none none 2 none 1 N/A 12811( 5) - 04-Jun-2012 12:57:51 - [ 5] Visit: 03 Visit Requirements: On Hold Comments: Additional Comments: WFC Flash checkout/cal Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 2 0.5 S FLASHCUR=MEDIUM, FLASHEXP=400 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 ACS/WFC ACCUM WFC DEF none none 1 none 1 N/A DARK 1 ACS/WFC ACCUM WFC DEF none none 2 none 1 N/A 12811( 5) - 04-Jun-2012 12:57:51 - [ 6] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: WFC Flash checkout/cal Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 1 0.5 S FLASHCUR=HIGH, FLASHEXP=400 ------------------------------------------------------------------------------------------------------------------------------------ 2 TUNGSTEN ACS/WFC ACCUM WFC F435W COMPRESSION=NONE 1 0.5 S Comments: Switch to other side of WFC shutter ------------------------------------------------------------------------------------------------------------------------------------ 3 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 1 0.5 S FLASHCUR=HIGH, FLASHEXP=400 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 ACS/WFC ACCUM WFC DEF none none none none 1 N/A TUNGSTEN 2 ACS/WFC ACCUM WFC F435W none none none none 1 N/A DARK 3 ACS/WFC ACCUM WFC DEF none none none none 1 N/A 12811( 5) - 04-Jun-2012 12:57:51 - [ 7] Visit: 05 Visit Requirements: On Hold Comments: Additional Comments: WFC Flash checkout/cal Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 1 360.5 S FLASHCUR=MEDIUM, FLASHEXP=40 ------------------------------------------------------------------------------------------------------------------------------------ 2 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 1 360.5 S FLASHCUR=LOW, FLASHEXP=40 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 ACS/WFC ACCUM WFC DEF none none none none 1 N/A DARK 2 ACS/WFC ACCUM WFC DEF none none none none 1 N/A 12811( 5) - 04-Jun-2012 12:57:51 - [ 8] Visit: 06 Visit Requirements: On Hold Comments: Additional Comments: WFC Flash checkout/cal Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 1 384.5 S FLASHCUR=LOW, FLASHEXP=16 ------------------------------------------------------------------------------------------------------------------------------------ 2 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 1 396.5 S FLASHCUR=LOW, FLASHEXP=4 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 ACS/WFC ACCUM WFC DEF none none none none 1 N/A DARK 2 ACS/WFC ACCUM WFC DEF none none none none 1 N/A 12811( 5) - 04-Jun-2012 12:57:51 - [ 9] Visit: 07 Visit Requirements: On Hold Comments: Additional Comments: WFC Flash checkout/cal Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 3 398.5 S FLASHCUR=LOW, FLASHEXP=2 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 ACS/WFC ACCUM WFC DEF none none 1 none 1 N/A DARK 1 ACS/WFC ACCUM WFC DEF none none 2 none 1 N/A DARK 1 ACS/WFC ACCUM WFC DEF none none 3 none 1 N/A 12811( 5) - 04-Jun-2012 12:57:51 - [ 10] Visit: 08 Visit Requirements: On Hold Comments: Additional Comments: WFC Flash checkout/cal Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 1 0.5 S FLASHCUR=LOW, FLASHEXP=400 ------------------------------------------------------------------------------------------------------------------------------------ 2 DARK ACS/WFC ACCUM WFC DEF COMPRESSION=NONE, 1 398.5 S FLASHCUR=MEDIUM, FLASHEXP=2 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 ACS/WFC ACCUM WFC DEF none none none none 1 N/A DARK 2 ACS/WFC ACCUM WFC DEF none none none none 1 N/A 12811( 5) - 04-Jun-2012 12:57:51 - [ 11] Summary Form for Proposal 12811 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters COMPRESSION=NONE, FLASHCUR=HIGH, FLASHCUR=LOW, FLASHCUR=MEDIUM, FLASHEXP=16, FLASHEXP=2, FLASHEXP=4, FLASHEXP=40, FLASHEXP=400, PAREXP=NONE ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements DEF, F435W ------------------------------------------------------------------------------------------------------------------------------------ Target Names DARK, TUNGSTEN ------------------------------------------------------------------------------------------------------------------------------------