! File: 3267C.PROP ! Database: PEPDB ! Date: 19-FEB-1994:00:36:54 coverpage: title_1: FIND GHRS MIRROR A1 COORDINATES proposal_for: SV/HRS pi_fname: DENNIS pi_lname: EBBETS pi_inst: BALL AEROSPACE pi_country: USA pi_phone: 303 939 5964 hours_pri: 3.58 num_pri: 1 hrs: Y ! end of coverpage abstract: line_1: This is a new SV test whose purpose is to line_2: help calibrate the onboard data base coordinates line_3: used by target acquisition mirror A1 to center a line_4: star in the 2.0 arc sec LSA during an onboard line_5: target acquisition. This is needed to ensure proper line_6: centering in the LSA before slewing to the SSA. We line_7: have not yet been successful in getting stars well line_8: centered in the SSA with mirror A1. Many SV, GTO line_9: GO programs will use bright stars, for line_10: which A1 is the essential choice of acquisition line_11: mirror. line_13: revised and shortened July 23, 1991 ! ! end of abstract general_form_proposers: lname: EBBETS fname: DENNIS inst: BALL AEROSPACE country: USA ! lname: GARNER fname: HARRY inst: BALL AEROSPACE country: USA ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: Mirror A1 is used for target acquisition of bright blue stars. line_2: For the most part all stars brighter than about V=6 use A1. line_3: This includes many of the most popular targets for interstellar line_4: medium studies, and several SV calibration stars. The flight line_5: software peakup algorithm moves the telescope until the measured line_6: position of a star coincides with the onboard data base value line_7: of its coordinates in detector deflection units. The software line_8: does not directly sense the geometrical center of the aperture. line_9: The software does not attempt to maximize the flux through the line_10: aperture. Any error in the onboard coordinates leads directly line_11: to an error in target centering. The attenuation with A1 is so line_12: great that we cannot detect the onboard spectral lamps, and line_13: therefore cannot perform a deflection calibration. Since some line_14: kind of calibration is necessary, we do the defcal with mirror line_15: N1, then the acq with A1. The offset between the N1 defcal and line_16: the A1 coordiantes has not been successfully established yet. line_17: Assuming that a stable offset even exists, this test is designed line_18: to measure it and make A1 useful for SSA applications. Without line_19: a good calibration, stars acquired with A1 will be misplaced at line_20: the SSA, and the desired S/N ratio will not be achieved. ! question: 3 section: 1 line_1: Part 1 - lines 10 - 80 line_2: onboard acq with mirror N1, peakup in LSA, map LSA line_3: take a short spectrum with G140L with star in LSA line_4: slew to SSA, map SSA, take same spectrum in SSA line_5: return to LSA, peakup and map again line_6: this leaves the star well centered in the LSA line_7: We think that N1 is very well calibrated, and will place line_8: the star accurately in both apertures. The spectra will line_9: show the true throughput ratio at 1300A when well centered. line_11: Part 2 - lines 110 - 160 line_12: initial image of LSA with A1 showing where N1 put the star line_13: peakup with A1, image LSA, short spectrum with G140L line_14: this will show how much A1 moved the star relative to N1's line_15: correct position. line_16: slew to the SSA, image, and repeat the spectrum - this should line_17: show a decreased ratio of SSA/LSA throughput due to miscentering line_18: return to LSA. line_19: These will measure the offset between N1 and A1 ! question: 3 section: 2 line_1: Part 3 lines 200 - 250 line_2: cycle back and forth between N1 and A1, doing only line_3: peakups in the LSA. each peakup will be preceeded by an line_4: N1 defcal. Since these are short exposures, they should line_5: be close to each other in time, so thermal and magnetic line_6: drift differences should be small. line_7: Analyze the offsets between A1 and N1 to derive line_8: a new estimate of the best onboard db position for A1 line_10: lines 900, 910 use the sequence twice, about 30 days apart line_11: the second execution should be after the A1 position has line_12: updated in the data base. Hopefully line_13: the offsets between A1 and N1 will be much smaller this line_14: time. The SSA/LSA flux ratio observed with the spectra line_15: should be independent of which mirror is used for centering. line_17: time estimates: line_18: each visit = 1.79 hrs (resource) * 1.5 = 2.7 hrs SU duration ! question: 4 section: 1 line_1: The precise position of the A1 image was not well determined line_2: during the ground based calibration programs. We have not line_3: been successful in inferring it from other data taken for line_4: other SV and SAO observations. We feel it is necessary to line_5: make this dedicated measurement to get a good calibration. ! question: 7 section: 1 line_1: The centroids of all the images will be measured to fix the line_2: X,Y position of the stellar image after each peakup. line_3: The initial pointing offset detected by the flight software line_4: is in the trailing UDL of each peakup data set. These line_5: numbers will be analyzed, averaged probably, to determine line_6: a mean error in the A1 position after an N1 defcal line_8: The revised A1 position will be placed in PDB PTLD table line_9: ZFDEFXNC for A1_LSA, A1_SSA, A1_SC1, A1_SC2 ! !end of general form text general_form_address: lname: EBBETS fname: DENNIS category: PI inst: BALL AEROSPACE ! lname: GARNER fname: HARRY category: COI inst: BALL AEROSPACE SYSTEMS GROUP addr_1: PO BOX 1062 addr_2: AR 1 city: BOULDER state: CO zip: 80306 country: USA phone: 303 939 4816 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: BD+75D325 descr_1: UV STANDARD pos_1: RA = 8H 10M 49.31S +/- 0.5S, pos_2: DEC= +74D 57' 57.5" +/- 0.5" equinox: 2000 pm_or_par: Y pos_epoch_bj: B pos_epoch_yr: 1983.80 ra_pm_val: -0.000467 ra_pm_unct: 0.000400 dec_pm_val: 0.0120 dec_pm_unct: 0.0100 comment_1: PLATE-ID=00LQ fluxnum_1: 1 fluxval_1: V=9.54 fluxnum_2: 2 fluxval_2: B-V=-0.36 fluxnum_3: 3 fluxval_3: F-CONT(1240)=8.0E-11 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 10.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 5S s_to_n: 50 fluxnum_1: 1 priority: 1 param_1: SEARCH-SIZE=5, param_2: FAINT=4000, req_1: ONBOARD ACQ FOR 20-250; req_2: CYCLE 0 / 10-250; ! linenum: 20.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 9.2S s_to_n: 50 fluxnum_1: 1 priority: 1 ! linenum: 30.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: IMAGE aperture: 2.0 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 96.8S s_to_n: 25 fluxnum_1: 1 priority: 1 ! linenum: 40.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G140L wavelength: 1300 num_exp: 1 time_per_exp: 57.6S s_to_n: 50 fluxnum_1: 3 priority: 1 param_1: STEP-PATT=4 ! linenum: 50.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: IMAGE aperture: 0.25 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 96.8S s_to_n: 25 fluxnum_1: 1 priority: 1 param_1: DELTA-X=1, param_2: DELTA-Y=1, param_3: PRECISION=HIGH, ! linenum: 60.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACCUM aperture: 0.25 sp_element: G140L wavelength: 1300 num_exp: 1 time_per_exp: 288.0S s_to_n: 50 fluxnum_1: 3 priority: 1 param_1: STEP-PATT=4, ! linenum: 70.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 9.2S s_to_n: 50 fluxnum_1: 1 priority: 1 ! linenum: 80.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: IMAGE aperture: 2.0 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 96.8S s_to_n: 25 fluxnum_1: 1 priority: 1 ! linenum: 100.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: IMAGE aperture: 2.0 sp_element: MIRROR-A1 num_exp: 1 time_per_exp: 484S s_to_n: 25 fluxnum_1: 1 priority: 1 ! linenum: 120.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-A1 num_exp: 1 time_per_exp: 460S s_to_n: 20 fluxnum_1: 1 priority: 1 ! linenum: 130.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: IMAGE aperture: 2.0 sp_element: MIRROR-A1 num_exp: 1 time_per_exp: 484S s_to_n: 25 fluxnum_1: 1 priority: 1 ! linenum: 140.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G140L wavelength: 1300 num_exp: 1 time_per_exp: 57.6S s_to_n: 50 fluxnum_1: 3 priority: 1 param_1: STEP-PATT=4 ! linenum: 150.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: IMAGE aperture: 0.25 sp_element: MIRROR-A1 num_exp: 1 time_per_exp: 484S s_to_n: 25 fluxnum_1: 1 priority: 1 param_1: DELTA-X=1, param_2: DELTA-Y=1, param_3: PRECISION=HIGH, ! linenum: 160.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACCUM aperture: 0.25 sp_element: G140L wavelength: 1300 num_exp: 1 time_per_exp: 288.0S s_to_n: 50 fluxnum_1: 3 priority: 1 param_1: STEP-PATT=4 ! linenum: 200.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-A1 num_exp: 1 time_per_exp: 230S s_to_n: 50 fluxnum_1: 1 priority: 1 ! linenum: 210.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 9.2S s_to_n: 50 fluxnum_1: 1 priority: 1 ! linenum: 220.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-A1 num_exp: 1 time_per_exp: 230S s_to_n: 50 fluxnum_1: 1 priority: 1 ! linenum: 230.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: IMAGE aperture: 2.0 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 96.8S s_to_n: 25 fluxnum_1: 1 priority: 1 ! linenum: 240.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 9.2S s_to_n: 50 fluxnum_1: 1 priority: 1 ! linenum: 250.000 sequence_1: DEF sequence_2: VISIT1 targname: BD+75D325 config: HRS opmode: IMAGE aperture: 2.0 sp_element: MIRROR-N1 num_exp: 1 time_per_exp: 96.8S s_to_n: 25 fluxnum_1: 1 priority: 1 ! linenum: 900.000 sequence_1: USE sequence_2: VISIT1 ! linenum: 910.000 sequence_1: USE sequence_2: VISIT1 req_1: AFTER 900 BY 30D +/- 10D ! ! end of exposure logsheet ! No scan data records found