! File: 1315C.PROP ! Database: PEPDB ! Date: 16-FEB-1994:13:27:33 coverpage: title_1: FOS-V8 VERIFICATION OF TIME-RESOLVED MODES proposal_for: SV/FOS pi_fname: BRUCE pi_lname: MARGON pi_inst: UNIVERSITY OF WASHINGTON pi_country: USA pi_phone: 206-543-0089 num_pri: 1 wf_pc: Y fos: Y time_crit: X ! end of coverpage abstract: line_1: A test will be performed to verify the time-resolved modes of the FOS. The test line_2: will check the asynchronous time-resolved mode line_3: by observing a stable, short period, variable star. line_5: This program has a low priority compared with other SV activities. ! ! end of abstract general_form_proposers: lname: ANGEL fname: ROGER inst: UNIVERSITY OF ARIZONA country: USA ! lname: MARGON fname: BRUCE title: PI inst: UNIVERSITY OF WASHINGTON country: USA ! lname: BARTKO fname: FRANK inst: MARTIN MARIETTA CORPORATION country: USA ! lname: DAVIDSEN fname: ARTHUR inst: JOHNS HOPKINS UNIVERSITY country: USA ! lname: HARMS fname: RICHARD inst: APPLIED RESEARCH CORPORATION country: USA ! lname: BOHLIN fname: RALPH inst: SPACE TELESCOPE SCIENCE INSTITUTE country: USA ! lname: FORD fname: HOLLAND inst: SPACE TELESCOPE SCIENCE INSTITUTE country: USA ! lname: BURBIDGE fname: E. mi: M. inst: UNIVERSITY OF CALIFORNIA, SAN DIEGO country: USA ! lname: BEAVER fname: EDWARD inst: UNIVERSITY OF CALIFORNIA, SAN DIEGO country: USA ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: In order to verify the functionality of the time-resolved modes of FOS, a line_2: stable high-speed variable star, with a well-measured period, needs to be line_3: observed. These modes will constitute the minority of FOS observations, but line_4: form one of the features that is unique to the instrument, and requires little line_5: time to test during the SV period. There are two objects - the Crab Pulsar and line_6: DQ Her - which constitute the needed "time-resolved standards." We propose to line_7: observe one of these objects using the synchronous time-resolved mode. This line_8: test leaves the time-tagged mode untested. ! question: 3 section: 1 line_1: In this test, we will observe one (1) high-speed variable line_2: star to verify the functionality of the time-resolved modes line_3: of the FOS. We will observe the Crab pulsar for ~1 hour line_4: or DQ Her for ~2 hours (including overhead) in the line_5: synchronous time-resolved mode. ! question: 3 section: 3 line_1: A detailed description of the Crab Pulsar observation is provided. line_2: COMMENSURABILITY OF CRAB AND CLOCK PERIODS: line_4: Because the Crab period will, in general, not be a rational line_5: number multiple of the FOS clock period, we will suffer some line_6: phase slippage due to roundoff errors. The FOS time periods line_7: are set by counting a 1.024/8 Mhz signal derived from the line_8: spacecraft master clock. All FOS exposures are thus some line_9: integer multiple of T(0) = (8/1.024) = 7.8125 microsec long. line_11: Since the Crab period is too short to be directly phase-sampled line_12: by the FOS, we need to use a beat frequency method to obtain line_13: these data. This means the Crab pulsar will only be in phase line_14: with the FOS clock at certain times. If we desire N phase line_15: bins, we can sample phases by choosing parameters so that line_17: N(LIV+DED) = (N+1)P(Crab) ! question: 3 section: 4 line_1: We also use LIV = P(Crab)/N and DED = P(Crab), as closely as line_2: possible. In reality, both LIV and DED must be an integer line_3: number of clock cycles: line_5: LIV = l*T(0), DED = m*T(0) --> LIV+DED = (l+m)*T(0) line_6: or LIV+DED = k*T(0) line_8: N(LIV+DED) = NkT(0) = (N+1)P --> k = (N+1/N)/(P/T(0)) line_10: The minimum change in k is dk = 1, corresponding to a change line_11: dP in the Crab: line_13: dk = 1 = (N+1/N)*(dP/T(0)) --> dP = (N/N+1)*T(0) line_15: The Crab period varies by dP in a time dt given by: line_17: dP = Pdot*dt --> dt = dP/Pdot = (N/N+1)*T(0)/Pdot line_19: Thus, line_21: dt = (8/9)*(7.8125E-6)/(4.22439E-13) = 1.643893E7 seconds line_22: = 190.2653742 days ! question: 3 section: 5 line_1: So, the Crab is in phase with the FOS master clock line_2: approximately every 190 days. line_4: Let us consider possible parameters for a March 3, 1990 line_5: observation. line_7: P(Crab) = 0.03337501 seconds line_8: Pdot(Crab) = 4.22439E-13 line_9: N = 8 line_11: LIV = l*T(0) = P/N = 0.03337501/8 = 0.004171876 seconds line_12: l = LIV/T(0) = 534.00 line_13: DED = m*T(0) = P = 0.03337501 seconds line_14: m = DED/T(0) = 4272.00 line_15: k = l + m = 4806 line_16: CYCLE-TIME = 8(LIV+DED) = 9P(Crab) = 0.300375085 seconds line_17: Readouts = 30 line_18: Patterns = 256 line_19: EXPOSURE TIME = Readout*Patterns*CYCLE-TIME = 2306.9 seconds line_20: DATA-RATIO = LIV/DED = 0.125 ! question: 3 section: 6 line_1: In order to accumulate the full integration time on the Crab line_2: target, we will need to halt exposures, read out the data, line_3: and then re-expose. The FOS allows a synchronous line_4: time-resolved mode that should enable us to restart each line_5: exposure correctly aligned in phase with the previous ones. line_6: WE WANT TO USE THIS CAPABILITY TO SEE IF IT FUNCTIONS line_7: PROPERLY. The data from each readout will be stored line_8: separately, so that if the attempt to phase-link the line_9: individual exposures fails, we will be able to use the data line_10: sets themselves to establish relative phases. line_12: The above observation will result in 30 readouts, with line_13: synchronous re-starts, so that the data can be directly line_14: co-added, provided that the pulsar and spacecraft clocks line_15: are in sufficient synchronization. The maximum time line_16: between readouts, dictated by the maximum values of PATTERNS line_17: (256) and the CYCLE-TIME, is 76.8s. ! question: 3 section: 7 line_1: PHASE SMEARING: line_3: Ideally, we wish to phase-lock FOS observations to the Crab line_4: period so that: line_6: N(LIV+DED) = N*k*T(0) = (N+1)P line_7: --> k = (N+1/N)*(P/T(0)) line_9: In general, this relationship will not hold for an exact line_10: integer k; if we match to the closest integer k, the real line_11: equation will be: line_13: N(k+f)*T(0) = (N+1)P, where -0.5 < f < +0.5 line_14: k+f = (N+1/N)*(P/T(0)) line_15: k = (N+1/N)*(P/T(0)) - f line_17: The true Crab period P = (N/N+1)*(k+f)*T(0), whereas the FOS line_18: clock approximation to the Crab period P(FOS) = (N/N+1)*k*T(0). line_19: The error line_21: del(P) = P-P(FOS) = f*(N/N+1)*T(0), ! question: 3 section: 8 line_1: and the relative error is line_3: del(P)/P = f/(k+f) line_5: This represents the phase slippage per Crab cycle. The total line_6: phase smearing, del(phase), during an observations time T, is line_7: just T/P time greater. Thus, line_9: del(phase) = (T/P)*(f/k+f) line_10: abs( del(phase) ) < (T/P)*(0.5/k) = T/2*k*P line_12: For March 1990, k=4806 and P=0.03337501 seconds. Then, line_14: del(phase) = (0.006234402)*T*f line_16: where T is the exposure time in seconds. line_18: To maintain 8 meaningful phase bins, we will require that line_20: abs (del(phase) ) < 0.5*N = 1/16 ! question: 3 section: 9 line_1: This implies line_3: abs( del(phase) ) = (0.006234402)*T*f < 1/16 line_4: T*f < 10.025 seconds line_6: Since T(max) = 76.8 seconds, then f<0.13, which provides a line_7: 49-day window during each 190-day cycle when 76.8-second long line_8: readouts are acceptable. line_10: In GF5, the parameters for all windows in 1990 and 1991 are line_11: provided. line_14: For DQ Her: line_15: P = 71.065877 s line_16: CYCLE-TIME = 71.065877 s line_17: Readouts = 6 line_18: Patterns = 15 line_19: Exposure = 6396 s ! question: 5 section: 1 line_1: If the Crab Pulsar is observed, we will need to do a line_2: WF/PC-assisted target acquisition. Proper phasing for our line_3: data, both between readouts and occultations, will be line_4: maintained using FOS flight software, using the sychronous line_5: restart capability. If DQ Her is observed, the data should line_6: be obtained at the appropriate phases of the orbital period. line_8: SV Prerequisites: line_9: Verification of mode II Binary Search target acquisition mode line_10: (Prop 2195) and WF/PC-assisted target acquisition mode (Prop line_11: 1427). line_13: Alternate target selection: line_14: The Crab pulsar is a high priority first choice. line_16: Minimum/Delta plan objects: line_17: All observations are delta plan. line_19: Pointing stability of 10% of the smallest aperture (0.3") line_20: used - 0.03" - is required. ! question: 5 section: 2 line_1: If the Crab Pulsar is observed, we will need to update the line_2: period based on when the observation is scheduled. line_5: SCHEDULING OF THE CRAB PULSAR OBSERVATIONS: line_7: Window: Feb. 7 - March 27, 1990 line_9: P(Crab) = 0.03337501 seconds line_10: LIV = l*T(0) = P/N = 0.004171876 seconds line_11: l = LIV/T(0) = 534.00 line_12: DED = m*T(0) = P = 0.03337501 seconds line_13: m = DED/T(0) = 4272.00 line_14: k = l + m = 4806 line_15: CYCLE-TIME = 8(LIV+DED) = 9P(Crab) = 0.300375085 seconds line_16: Readouts = 30 line_17: Patterns = 256 line_18: EXPOSURE TIME = Readout*Patterns*CYCLE-TIME = 2306.9 seconds line_19: DATA-RATIO = LIV/DED = 0.125 ! question: 5 section: 3 line_1: Window: Aug. 16 - Oct. 3, 1990 line_3: P(Crab) = 0.03338194 seconds line_4: LIV = l*T(0) = P/N = 0.004172743 --> 0.004171875 seconds line_5: l = LIV/T(0) = 534.11 --> 534 line_6: DED = m*T(0) = P = 0.03338194 --> 0.033382813 seconds line_7: m = DED/T(0) = 4272.89 --> 4273 line_8: k = l + m = 4807 line_9: CYCLE-TIME = 8(LIV+DED) = 9P(Crab) = 0.3004375 seconds line_10: Readouts = 30 line_11: Patterns = 256 line_12: EXPOSURE TIME = Readout*Patterns*CYCLE-TIME = 2307.4 seconds line_13: DATA-RATIO = LIV/DED = 0.125 ! question: 5 section: 4 line_1: Window: Feb. 25 - April 13, 1991 line_3: P(Crab) = 0.03338952 seconds line_4: LIV = l*T(0) = P/N = 0.00417369 --> 0.004171875 seconds line_5: l = LIV/T(0) = 534.23 --> 534 line_6: DED = m*T(0) = P = 0.03338952 --> 0.03339063 seconds line_7: m = DED/T(0) = 4273.86 --> 4274 line_8: k = l + m = 4808 line_9: CYCLE-TIME = 8(LIV+DED) = 9P(Crab) = 0.3005432 seconds line_10: Readouts = 30 line_11: Patterns = 256 line_12: EXPOSURE TIME = Readout*Patterns*CYCLE-TIME = 2308.2 seconds line_13: DATA-RATIO = LIV/DED = 0.125 ! question: 5 section: 5 line_1: Window: Sept. 2 - Oct. 20, 1991 line_3: P(Crab) = 0.03339589 seconds line_4: LIV = l*T(0) = P/N = 0.004174486 --> 0.004171875 seconds line_5: l = LIV/T(0) = 534.33 --> 534 line_6: DED = m*T(0) = P = 0.03339589 --> 0.03339844 seconds line_7: m = DED/T(0) = 4274.67 --> 4275 line_8: k = l + m = 4809 line_9: CYCLE-TIME = 8(LIV+DED) = 9P(Crab) = 0.3005625 seconds line_10: Readouts = 30 line_11: Patterns = 256 line_12: EXPOSURE TIME = Readout*Patterns*CYCLE-TIME = 2308.3 seconds line_13: DATA-RATIO = LIV/DED = 0.125 ! question: 5 section: 6 line_1: line_7: Comment for line 4: The above is the preferred object. The line_8: total time on target for this observation is exposure time + line_9: readout time + occultation time. For the 4kbps rate, this is line_10: 2307s + 30 readouts x 16s + 2700s = 5483s. Re-phasing will be line_11: performed with FOS software, so the clock on the NSSC-1 line_12: MUST not be changed during occultation. line_14: Comment for line 7: The above is the backup object. The line_15: total time on target for this observation is exposure time + line_16: readout time + occultation time. For the 4kbps rate, this is line_17: 6396s + 6 readouts x 16s + 2700s = 9192s. Re-phasing will be line_18: performed with FOS software, so the clock on the NSSC-1 MUST line_19: not be changed during occultation. Since the exposure time line_20: includes SAA, occultation, etc., the PHASE requirement means that the line_21: specified range MUST be during an observable period (i.e. not SAA, occultation, line_22: etc.). ! question: 6 section: 1 line_1: This test is not stray light sensitive. ! question: 7 section: 1 line_1: Data reduction will be performed at the STScI, and the analysis will be line_2: performed using FOS IDT computer facilities. Since this test is strictly a line_3: verification, no calibration data will be obtained. ! question: 8 section: 1 line_1: This test must be supported by an observation from a ground-based telescope line_2: within 3 weeks of the FOS observation; if possible, the data should be obtained line_3: within 24-48 hours of the test. The telescope must be equipped with a high line_4: speed photometer and magnetic tape data acquisition system. The purpose of the line_5: ground-based observation is to independently determine the period and phase of line_6: the test object; for both objects, these properties drift on a timescale of line_7: months and must be redetermined before the stars can be used as calibrators. line_9: The STScI ground system sofware must be in a sufficient state of maturity that line_10: spacecraft clock UT time can be translated into "real" UT i.e. corrected for line_11: all propogation delays, and supplied to us for analysis with a minimum of line_12: delay. In this context, "minimum" means we don't need it in realtime, but we line_13: cannot analyze FOS performance until after we get these corrected times. ! question: 10 section: 1 line_1: Data analysis, research assistant support, and funding will be provided under line_2: NASA's FOS GTO contract(s). ! !end of general form text general_form_address: lname: MARGON fname: BRUCE category: PI inst: UNIVERSITY OF WASHINGTON addr_1: DEPT. OF ASTRONOMY addr_2: FM-20 city: SEATTLE state: WA zip: 98195 country: USA ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: CRAB-PULSAR-FIELD descr_1: FIELD OF PULSAR AT CENTER descr_2: OF CRAB NEBULA pos_1: RA= 05H 31M 31.4S +/- 0.1S, pos_2: DEC= +21D 58' 54.4" +/- 0.1" equinox: 1950 fluxnum_1: 1 fluxval_1: V=16.0 +/- 0.4 ! targnum: 2 name_1: DQ-HER descr_1: BRIGHT, PULSATING OLD NOVA pos_1: RA= 18H 07M 30.35S +/- 0.03S, pos_2: DEC= +45D 51' 31.9" +/- 1" equinox: 2000 comment_1: DQ HER IS THE ALTERNATE TARGET. comment_2: THE CRAB PULSAR IS HIGHLY comment_3: PREFERRED CHOICE. fluxnum_1: 1 fluxval_1: V=14.0 +/- 0.3 ! targnum: 3 name_1: CRAB-PULSAR descr_1: PULSAR AT CENTER OF CRAB NEBULA pos_1: RA= 05H 31M 31S +/- 5S, pos_2: DEC= +21D 58' 54" +/- 10", pos_3: TBD-EARLY equinox: 1950 fluxnum_1: 1 fluxval_1: V=16.0 +/- 0.4 ! targnum: 4 name_1: CRAB-PULSAR-OFFSET descr_1: OFFSET STAR IN CRAB FIELD pos_1: RA= 05H 31M 31S +/- 5S, pos_2: DEC= +21D 58' 54" +/- 10", pos_3: TBD-EARLY equinox: 1950 fluxnum_1: 1 fluxval_1: V=18.0 +/- 0.5 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 2.000 targname: CRAB-PULSAR-FIELD config: WFC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 40S fluxnum_1: 1 priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: EARLY ACQ FOR 3; req_2: CYCLE 0/2-7; req_3: SELECT 1 OF 2-4 OR 6-7; req_4: COND IF CRAB-PULSAR IS OBSERVABLE DURING req_5: SV; comment_1: ALL OBSERVATIONS ARE SV DELTA PLAN. ! linenum: 3.000 targname: CRAB-PULSAR-OFFSET config: FOS/RD opmode: ACQ/BINARY aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 30S fluxnum_1: 1 priority: 1 req_1: ONBOARD ACQ FOR 4; req_2: AFTER 2 BY 60D; req_3: REQ DATA FROM 2; req_4: COND IF CRAB-PULSAR IS OBSERVABLE DURING req_5: SV; comment_1: THE EXPOSURE TIME WILL BE comment_2: REVISED BASED ON THE TRUE comment_3: MAG OF THE STAR. ! linenum: 4.000 targname: CRAB-PULSAR config: FOS/RD opmode: PERIOD aperture: 1.0 sp_element: G650L num_exp: 1 time_per_exp: 4956.19S fluxnum_1: 1 priority: 1 param_1: BINS=8, param_2: SUB-STEP=1, param_3: COMB=NO, param_4: CYCLE-TIME=.3003751, param_5: DATA-RATIO=0.125 req_1: REQ UPDATE; req_2: PERIOD 190D +/-0.1D; req_3: ZERO-PHASE JD2447953.5 +/- 0.1D; req_4: PHASE 0.0 +/- 0.13; req_5: COND IF CRAB-PULSAR IS OBSERVABLE DURING req_6: SV; comment_1: THE CYCLE-TIME AND EXPOSURE comment_2: TIME NEED TO BE UPDATED BASED comment_3: ON THE DATE OF THE OBSERVATION. comment_4: CONT. IN GF5. ! linenum: 6.000 targname: DQ-HER config: FOS/RD opmode: ACQ/PEAK aperture: 1.0 sp_element: G570H num_exp: 1 time_per_exp: 0.24S fluxnum_1: 1 priority: 1 param_1: SEARCH-SIZE=6, param_2: SCAN-STEP=0.7 req_1: ONBOARD ACQ FOR 6.1; req_2: PHASE 0.21 +/- 0.03; req_3: PERIOD 0.19362087D +/- 0.001S; req_4: ZERO-PHASE JD2434954.94425 +/- 0.000001D; req_5: COND IF DQ-HER OBSERVABLE DURING SV; ! linenum: 6.100 targname: ^ config: ^ opmode: ^ aperture: 0.3 sp_element: ^ num_exp: 1 time_per_exp: 0.44S fluxnum_1: 1 priority: 1 param_1: SEARCH-SIZE=5, param_2: SCAN-STEP=0.2 req_1: ONBOARD ACQ FOR 6.2; req_2: COND IF DQ-HER OBSERVABLE DURING SV; ! linenum: 6.200 targname: ^ config: ^ opmode: ^ aperture: ^ sp_element: ^ num_exp: 1 time_per_exp: 13.0S fluxnum_1: 1 priority: 1 param_1: SEARCH-SIZE=5, param_2: SCAN-STEP=0.05 req_1: ONBOARD ACQ FOR 7; req_2: COND IF DQ-HER OBSERVABLE DURING SV; ! linenum: 7.000 targname: ^ config: ^ opmode: PERIOD aperture: 1.0 sp_element: G650L wavelength: 3750-7500 num_exp: 1 time_per_exp: 225.04M fluxnum_1: 1 priority: 1 param_1: BINS=8, param_2: CYCLE-TIME=71.065877 req_1: COND IF DQ-HER OBSERVABLE DURING SV; comment_1: THE WAVELENGTH RANGE WILL NEED TO comment_2: BE RESTRICTED TO FIT INTO MEMORY. comment_3: CONT. IN GF5. ! ! end of exposure logsheet ! No scan data records found