Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3142c Report Date: 09-May-96:18:04 Version: ********** Check-in Date: ********** 1.Proposal Title: OTA BAFFLE REJECTION MEASUREMENT-REVISED ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SV/OLT Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Pierre Bely ST SCI USA (301)338-4780 ------------------------------------------------------------------------------------ 7. Abstract Test Objective: Measure the effectiveness of the HST OTA baffle system in rejecting light of nearby bright objects. Verify that the stray light tolerance (23rd magnitude/square arcsec at the focal plane) is met with the present viewing limits established for the sun (>50 degrees), moon (>15 degrees) and the bright earth limb (>80 degrees) from the OTA axis. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 3.00 par: 0 10. Num targs pri: 5 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3142c PI: Pierre Bely Proposal Title: OTA BAFFLE REJECTION MEASUREMENT-REVISED ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pierre Bely ST SCI USA X Olivia Lupie ST SCI USA Peter Stockman ST SCI USA X Robert Jayroe MSFC USA Andy Lubenow ST SCI USA ------------------------------------------------------------------------------------ 2. Scientific Justification. ****Test Description: In order to realize the full potential of HST for the detection of faint astronomical sources, stray light must be negligible. Extensive study and modelling resulted in the state of the art baffling system on HST. Testing the effectiveness of the system is not practical on the ground prior to launch. This test will measure the overall effectiveness of the off-axis rejection capability of bright sources at large angles while in orbit and verify the 'level-1' stray light requirement. Estimated test duration: Total exposure time= 3 hours, Total w/overhead= 5.5 hours. ------------------------------------------------------------------------------------ 3. Description of proposed observations. Use WFC in 2x2 SUM mode as an area photometer to measure the scattered light background in several filters and at several distances from the full moon and at 50 degrees from the sun but 3 different roll orientations. 1) OFFSETS FROM THE FULL MOON: A series of exposures in combinations of filters VUV,U,V,and R filters at each of four offset pointings: 4,8,20, and 30 degrees. 2) OFFSETS FROM NEW MOON (two weeks later): at SAME POINTING as (1), repeat the 20 and 30 degree exposures for background subtraction. No background exposures are needed for the 4 and 8 degree offsets because of the brightness of the stray light. WFC CCDs must be preflashed before all low light-level exposures. WPC UV flooding is required prior to the start of the test but not during any portion of the test. The quantum efficiency during this test should be worse than 90% that at the time of the flood. Purges are included for those frames with t_exp => 1000S for possible over-exposure by spurious stars. Special Requirement SEQ NO GAP is used for those groups of exposures containing a purge to insure the purge occurs at end of sequence; otherwise 'GROUP' is acceptable. *****TEST STEPS - Easy to Read summary of Exposures: WFPC Configuration: IMAGE,ALL,2x2 SUM Mode. ***SEQUENCE 1 - OFFSETS FROM FULL MOON ***** Exp line 10: Preflash, 4 deg, VUV F284W, exp time 200s. Exp line 11: 4 deg, UV F336W, exp time 140s. Exp line 12: 4 deg, V F569W, exp time 10s. Exp line 13: 4 deg, R F675W, exp time 10s. Exp line 20: Preflash, 8 deg, VUV F284W, exp time 400s. Exp line 21: 8 deg, UV F336W, exp time 100s. Exp line 22: 8 deg, V F569W, exp time 60s. Exp line 23: 8 deg, R F675W, exp time 30s. Exp line 30: Preflash, 20 deg, R F675W, exp time 200s. Exp line 31: Preflash, 20 deg, V F569W, exp time 400s. Exp line 32: Preflash, 20 deg, UV F336W, exp time 1000s, Purge. Exp line 40: Preflash, 30 deg, V F569W, exp time 1260s, Purge. SEQUENCE 2 NEW MOON BACKGROUNDS Exp line 50: Preflash, 20 deg, R F675W, exp time 200s. Exp line 51: Preflash, 20 deg, V F569W, exp time 400s. Exp line 52: Preflash, 20 deg, UV F336W, exp time 1000s,purge. Exp line 60: Preflash, 30 deg, V F569W, exp time 1260s,purge. SEQUENCE 3 OFFSET FROM SUN ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Submitted as an Observatory Level Test Page 3 ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. SCHEDULING REQUIREMENTS: 1 - GYRO Tracking. 3 - UV FLOOD Required prior to test; WFC quantum efficiency 90% that at time of UV flood. 4 - Because of long exposures, schedule test after TEC turn-on. 5 - Exp Lines 10-40 require Full Moon (+/- 0.5 days) 6 - Exp Lines 50-60 require New Moon (+/- 4.0 days). Perform within two weeks of lines 10-40. 8 - Order of Sequences 1 and 2 may be interchanged to accommodate lunar phase requirements. 9 - No observations during SAA passage. 10 - FGS to WFPC not required; lambda/8 acceptable. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. Test Repetition: none. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Real Time Data Analysis Requirements: Not anticipated at this time. Offline Data Analysis Plans: Dedicated STSDAS programs to determine the incident flux attenuation factors as a function of the off-axis angle and wavelength. Description of procedures are available in internal STScI documentation. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. ***SIGNIFICANT AMOUNTS OF STRAY LIGHT IN FOCAL PLANE DURING THIS OLT.**** ***Possible saturation by background stars**** ------------------------------------------------------------------------------------ 11. Address Information Name: OLIVIA LUPIE Category: CON Institution: ST SCI Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ Name: BELY PIERRE Category: PI Institution: ST SCI Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 3142c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 MOON-04 OFFSET TARGET 4 DEGREES RA= 159.7803 D +/- 0.01D, 2000 1 SURF-CONT-BKG(5600)=74+/-10 E-17 FROM MOON, NORTH. DEC= 8.7983 D +/- 0.01D ------------------------------------------------------------------------------------------------------------------------------------ 2 MOON-08 OFFSET TARGET 8 DEGREES RA= 159.7803 D +/- 0.01D, 2000 1 SURF-CONT-BKG(5600)=74+/-10 E-18 FROM MOON, NORTH. DEC= 12.7983 D +/- 0.01D ------------------------------------------------------------------------------------------------------------------------------------ 3 MOON-20 OFFSET TARGET 20 RA= 159.7803 D +/- 0.01D, 2000 1 SURF-CONT-BKG(5600)=74+/-10E-20 DEGREES DEC= 24.7983 D +/- 0.01D FROM MOON, NORTH. ------------------------------------------------------------------------------------------------------------------------------------ 4 MOON-30 OFFSET TARGET 30 RA= 159.7803 D +/- 0.01D, 2000 1 SURF-CONT-BKG(5600)=74+/-10E-23 DEGREES DEC= 34.7983 D +/- 0.01D FROM MOON, NORTH. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3142c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DEFINE # WFC IMAGE ALL F284W SUM=2X2 1 1S 1 1 VUV ------------------------------------------------------------------------------------------------------------------------------------ 2 DEFINE # WFC IMAGE ALL F336W SUM=2X2 1 1S 1 1 UV ------------------------------------------------------------------------------------------------------------------------------------ 3 DEFINE # WFC IMAGE ALL F569W SUM=2X2 1 1S 1 1 V ------------------------------------------------------------------------------------------------------------------------------------ 4 DEFINE # WFC IMAGE ALL F675W SUM=2X2 1 1S 1 1 R ------------------------------------------------------------------------------------------------------------------------------------ 5 DEFINE # WFC IMAGE ALL F284W SUM=2X2 1 1S 1 1 VUV-PF PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ 6 DEFINE # WFC IMAGE ALL F336W # 1 1S 1 1 UV-PF ------------------------------------------------------------------------------------------------------------------------------------ 7 DEFINE # WFC IMAGE ALL F569W ^ # 1 1S 1 1 V-PF ------------------------------------------------------------------------------------------------------------------------------------ 8 DEFINE # WFC IMAGE ALL F675W ^ SUM=2X2 1 1S 1 1 ^ R-PF PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ 10 USE VUV MOON-04 X200 GROUP 10-60 WITHIN -PF 16D CYCLE 0 /10-60 GUIDE TOL 30" /10- 60 GROUP 10-13 NO GAP AT 28-FEB-91:17:58 +/- 12H ------------------------------------------------------------------------------------------------------------------------------------ 11 USE UV MOON-04 X140 ------------------------------------------------------------------------------------------------------------------------------------ 12 USE V MOON-04 X10 ------------------------------------------------------------------------------------------------------------------------------------ 13 USE R MOON-04 X10 ------------------------------------------------------------------------------------------------------------------------------------ 20 USE VUV MOON-08 X400 GROUP 20-23 NO GAP -PF AT 28-FEB-91:17:58 +/- 12H ------------------------------------------------------------------------------------------------------------------------------------ 21 USE UV MOON-08 X100 ------------------------------------------------------------------------------------------------------------------------------------ 22 USE V MOON-08 X60 ------------------------------------------------------------------------------------------------------------------------------------ 23 USE R MOON-08 X30 ------------------------------------------------------------------------------------------------------------------------------------ 30 USE R- MOON-20 X200 SEQ 30-40 NO GAP PF AT 28-FEB-91:17:58 +/- 12H ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3142c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 31 USE V- MOON-20 SUM=2X2 X400 PF PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ 32 USE UV- MOON-20 SUM=2X2 X1000 PF PRE-FLASH=YES PURGE=YES ------------------------------------------------------------------------------------------------------------------------------------ 40 USE V- MOON-30 SUM=2X2 X1260 PF PRE-FLASH=YES PURGE=YES ------------------------------------------------------------------------------------------------------------------------------------ 50 USE R- MOON-20 X200 SEQ 50-60 NO GAP PF SAME POS FOR 50 AS 30 AT 16-MAR-91:07:45 +/- 4 D Comments: BACKGROUND OFFSET FROM NEW MOON ------------------------------------------------------------------------------------------------------------------------------------ 51 USE V- MOON-20 SUM=2X2 X400 SAME POS PF PRE-FLASH=YES FOR 51 AS 31 Comments: BACKGROUND OFFSET FROM NEW MOON ------------------------------------------------------------------------------------------------------------------------------------ 52 USE UV- MOON-20 SUM=2X2 X1000 SAME POS PF PRE-FLASH=YES FOR 52 AS 32 PURGE=YES Comments: BACKGROUND OFFSET FROM NEW MOON ------------------------------------------------------------------------------------------------------------------------------------ 60 USE V- MOON-30 SUM=2X2 X1260 SAME POS PF PRE-FLASH=YES FOR 60 AS 40 PURGE=YES Comments: BACKGROUND OFFSET FROM NEW MOON ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3142c [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SUM=2X2 PRE-FLASH=YES PURGE=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal for SV/OLT ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 3.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ^ GROUP 10-60 WITHIN 16D; CYCLE 0 /10-60; GUIDE TOL 30" /10-60; GROUP 10-13 NO GAP; AT 28-FEB-91 17 58 +/- 12H; GROUP 20-23 NO GAP; SEQ 30-40 NO GAP; SEQ 50-60 NO GAP; SAME POS FOR 50 AS 30; AT 16-MAR-91 07 45 +/- 4 D; SAME POS FOR 51 AS 31; FOR 52 AS 32; FOR 60 AS 40; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F284W F336W F569W F675W ------------------------------------------------------------------------------------------------------------------------------------ Target Names MOON-04 MOON-08 MOON-20 MOON-30 ------------------------------------------------------------------------------------------------------------------------------------