! File: 2141C.PROP
! Database: PEPDB
! Date: 17-FEB-1994:01:29:10
coverpage:
title_1: SPACECRAFT GLOW MEASUREMENT TEST
proposal_for: SV/OLT
pi_fname: PIERRE
pi_lname: BELY
pi_inst: ST SCI
pi_country: USA
pi_phone: (301)338-4780
hours_pri: 6.00
num_pri: 1
wf_pc: Y
foc: Y
time_crit: N
! end of coverpage
abstract:
line_1: Test Objective:
line_3: Measure the broadband intensity and spectral distribution of HST
line_4: induced glow (i.e., "shuttle glow") resulting from its passage
line_5: through the ambient upper atmosphere. Determine the glow
line_6: intensity dependence on the HST spatial orientation relative
line_7: to the HST orbital parameters. This test will be repeated
line_8: after 6 months to study outgassing effects. Rev 1/89,4/89.
line_10: Revised 3/21/90 by PStanley to delete REPEAT requirement on line 11.
!
! end of abstract
general_form_proposers:
lname: LUPIE
fname: OLIVIA
inst: ST SCI
country: USA
!
lname: BELY
fname: PIERRE
title: P.I.
inst: ST SCI
country: USA
esa: Y
!
lname: PARESCE
fname: FRANCESCO
inst: ST SCI
country: USA
esa: Y
!
lname: CLARKE
fname: JOHN
inst: MSFC
country: USA
!
lname: TOTH
fname: BRUCE
inst: STSCI
country: USA
!
lname: O'DELL
fname: ROBERT
inst: RICE UNIVERSITY
country: USA
!
! end of general_form_proposers block
general_form_text:
question: 2
section: 1
line_1: Test Description:
line_3: The "spacecraft glow" effect in the HST environment could introduce
line_4: a spurious background in the observations of all HST science
line_5: instruments particularly for long exposures of very faint objects.
line_6: At present, there is no mission constraint to limit observations when
line_7: this effect may be present, that is, at times when the in-plane HST
line_8: velocity vector points in the vicinity of the targets. This test
line_9: is designed to measure the intensity and the wavelength characteristics
line_10: of any S/C glow that may be present under this worst case condition.
line_11: Because of the faintness of the phenomenon (predicted to be
line_12: 25th magnitude per arc second square in the red), this OLT must
line_13: be performed under minimum conditions of background and stray
line_14: light illumination. All target and environmental constraints
line_15: are described in detail in GF #5.
!
question: 3
section: 1
line_1: To allow differentiation from the background and characterization
line_2: of the glow with the attack angle (angle between the HST velocity
line_3: vector and line of sight), 3 WFC 8-minute exposures will
line_4: be obtained contiguously while in shadow. The first of the
line_5: exposures must start as soon after target rise as possible.
line_6: Note that the Dark requirement may be lifted on the 3rd
line_7: observation if the last 1-2 minutes of that observation falls
line_8: outside of shadow.
line_10: The wavelength dependence of the glow will be measured by
line_11: repeating the observations with different filters over 2 additional
line_12: orbits and then observing with the FOC during a fourth orbit. Because of the
line_13: target faintness, a WF/PC bias and dark frame are required before and after
line_14: each set of observations during each orbit. Orbit 4 FOC exposures will provide
line_15: attack angle dependence of Lyman-alpha glow in UV.
!
question: 3
section: 2
line_1: The LOS will be parallel to the HST velocity vector
line_2: 4 minutes after the start of first observation of the second
line_3: orbit. This requirement (described further in GF.5) allows
line_4: the attack angle to be about equal to zero at the midpoint of the first
line_5: observation of the second orbit, and near but equally displaced
line_6: from zero during the first exposure of the other orbits.
line_7: The pointing is fixed and the same for all measurements in this test.
line_8: GYRO Tracking is acceptable and requested.
!
question: 3
section: 3
line_1: **Attack Angle, Orbit Geometry, and Test Design**
line_3: The velocity vector sweeps an angle of about 30.5 deg in 8 minutes.
line_4: The angle between the LOS and the velocity vector,
line_5: at the mid-point of an 8 minute exposure is 0, 50, and 100 degrees
line_6: for the 1st, 2nd, and 3rd exposures respectively, in an orbit.
line_7: The horizon drop-off angle for the HST orbit is about 22.5 degrees.
line_8: This means that for an LOS coincident with the velocity vector
line_9: at the midpoint of an observation will intercept the earth's limb
line_10: at the start of the observation if the exposure
line_11: duration is longer than 11.5 minutes. For an 8 minute observation,
line_12: the target LOS will be about 7 degrees above the earth's limb
line_13: at the start of the observation. Note that the variation in
line_14: the attack angle due to the orbital precession over four
line_15: orbits is less than 2 degrees.
!
question: 4
section: 1
line_1: Submitted as an Observatory Level Test
!
question: 5
section: 1
line_1: The scheduling constraints on this test are
line_2: listed in the following sections.
line_3: The target will be described as a moving
line_4: target but with a fixed pointing.
!
question: 5
section: 2
line_1: *****Test Schedule Constraints:
line_2: 1) Minimize scattered light from earth and moon:
line_3: - Phase of moon: between new (- 2 days) or first quarter (+ 2 days).
line_5: - Target observations taken during DARK TIME (spec. req).
line_6: 2) Minimize zodiacal light - orbital velocity vector points
line_7: furthest from the ecliptic (within +/- 10 degrees of plane).
line_8: Limit observing times to those months of the year
line_9: when this condition occurs (optimum months are Nov through
line_10: January, May through July).
line_13: 3) Minimize galactic background light by selecting those times when
line_14: the velocity vector is >= 20 degrees from the galactic plane.
line_15: 4) No data through the SAA
line_16: 5) POINTING: First exposure in each non-int sequence to start
line_17: as soon after target rise as possible within shadow.
line_18: The target will be the direction of the velocity vector
line_19: 4 (+/- 1) minutes after the START of this first observation
line_20: of the Second orbit. This will be the pointing for all 4 orbits.
line_21: 6) TRACKING: GYRO TRACK IS ACCEPTABLE AND REQUESTED.
!
question: 5
section: 3
line_1: TARGET SPECIFICATION:
line_3: Solar_System Level 1: FILE=VEL_EPHEM.DAT.
line_4: SPSS to receive from proposers
line_5: a file containing the target ephemeris containing 365 entries, one
line_6: position per day for a year. This file will be generated
line_7: from the predicted state vector file. A series of WINDOW
line_8: intervals will accompany the data set. The WINDOWS will
line_9: reflect the requirements of LOS with respect to
line_10: ecliptic and galactic plane. The requirement on SPSS therefore,
line_11: will be to sschedule the first observations per orbit as soon
line_12: into earth shadow as possible and to take into account the
line_13: lunar phase requirements.
line_15: File Generation: the file data will be constructed from the epehemeris
line_16: the HST velocity vector as a function of time and the time
line_17: of earth shadow entry as a function of day in the year.
line_18: The data set and window determination may be extracted from
line_19: a state vector file and processed through specialized
line_20: software we have constructed.
line_22: CAUTIONS: Predicted HST orbit is required for a year and
line_23: multiple updates to the ephemerides and the WINDOWS are required.
!
question: 5
section: 4
line_1: ALTERNATIVE TARGET SPECIFICATION:
line_3: Solar_System Level 1: STD = Orbit Pole
line_4: Specification in this way relieves the external interface with SPSS
line_5: and the manipulation of complex HST orbit data with numerous updates.
line_6: Subsequent Level 2 and Level targets will be necessary to
line_7: link the orbit pole with the orbit plane abd with the sun angle
line_8: constraint. Similar Window requirements will be used to satisfy the
line_9: constraints listed in section 5-2.
line_11: This method is TBD pending potential scheduling system
line_12: enhancements to:
line_13: 1) accommodate the use of the 'Orbit-pole' as a standard target,
line_14: 2) to devise a method to use level 2-3 'TYPE=XXXX' targets to describe
line_15: an offset relative to the pole which puts the LOS into the
line_16: orbital plane (90 deg) and then uses the direction to the sun to
line_17: pin down the LOS at entry into umbral shadow.
line_18: (ie, specify angle from sun vector - currently not achievable
line_19: through the TYPE=PA_SUN specification in the current proposal
line_20: instructions).
!
question: 5
section: 5
line_1: --- TEST PREREQUISITES:
line_2: o Level 1 optical image quality not required. (lambda/8 is
line_3: sufficient)
line_4: o Mini-OFAD verification is desireable but not necessary
line_5: o WF/PC UV Flood and pre-flash capabilities operational (SV/1431)
line_6: o WF/PC cooled to nominal operating temperatures (SV/1431)
line_7: o WF/PC preliminary focus setting established (OV/1482)
line_8: o FOC preliminary focus setting established (SV/1507)
line_11: --CAUTIONS:-- When the number of potential targets locations
line_12: are sufficiently minimized or selected, we must make a
line_13: brightness alert check of the candidate fields for protection of
line_14: FOVs.
!
question: 6
section: 1
line_1: Dark times are required for this OLT since the expected
line_2: magnitude level of the S/C glow effect is extremely faint.
line_3: Considerations of orbital geometry relative to the positions of
line_4: the sun, moon, ecliptic plane and galactic plane and even the
line_5: selection of an intrinsically dark portion of the sky as a
line_6: target will all be required to insure meaningful measurements
line_7: of the S/C glow.
!
question: 7
section: 1
line_1: Real Time Data Analysis Requirements:
line_2: Not anticipated at this time.
line_3: Offline Data Analysis Requirements:
line_4: For WF/PC Exposures:
line_5: o Process each of the 12 frames for bias subtraction and
line_6: normalization for relative sensitivity variation (flat
line_7: fielding).
line_8: o Select the image area which is common to the 9 frames
line_9: o Determine a single mean flux for each of the WFC and FOC
line_10: images. Because the image will be contaminated by field
line_11: stars and extended sources, the mean (or modal) flux level
line_12: for the image is most easily determined from the spatial
line_13: intensity distribution function. For each image, construct
line_14: a histogram of the number of pixels above a given count as
line_15: a function of the count rate. Determine the mode of the
line_16: major component of the distribution which is the background.
line_17: The corresponding count rate defines the mean flux of the
line_18: background portion of the image.
line_19: o Add all remaining pixels in each individual frames together
line_20: o Compare aggregated intensities of the last frame of each
line_21: orbit (reference frames) relative to each other and against
line_22: zodiacal light to calibrate (or verify) OTA and WF/PC
line_23: throughput efficiency as a function of wavelength.
!
question: 7
section: 2
line_1: o Compare the results of the repetition of the test after
line_2: 6 months to those of the original test to obtain possible
line_3: time dependence effects.
!
!end of general form text
general_form_address:
lname: BELY
fname: PIERRE
category: PI
inst: ST SCI
addr_1: 3700 SAN MARTIN DRIVE
city: BALTIMORE
state: MD
zip: 21218
country: USA
!
lname: LUPIE
fname: OLIVIA
category: CON
inst: ST SCI
addr_1: 3700 SAN MARTIN DRIVE
city: BALTIMORE
state: MD
zip: 21218
country: USA
!
! end of general_form_address records
fixed_targets:
targnum: 1
name_1: GLOW-TAR
pos_1: RA = 135.3087D +/-0.001D,
pos_2: DEC = 27.7292D +/-0.001D
equinox: J2000
comment_1: CYCLE 0 OBSERVATION
fluxnum_1: 1
fluxval_1: SURF(V)=25 +/- 0.5
!
! end of fixed targets
! No solar system records found
! No generic target records found
exposure_logsheet:
linenum: 1.000
sequence_1: DEF
sequence_2: CALIB1
targname: BIAS
config: WFC
opmode: IMAGE
aperture: ALL
sp_element: F850LP
num_exp: 1
time_per_exp: 0 S
priority: 1
param_1: SUM=2X2,
param_2: PRE-FLASH=YES
req_1: CYCLE 0 / 1-78;
!
linenum: 2.000
sequence_1: ^
sequence_2: ^
targname: DARK
config: ^
opmode: ^
aperture: ^
sp_element: ^
num_exp: 1
time_per_exp: 8 M
priority: ^
param_1: ^
param_2: ^
!
linenum: 7.000
sequence_1: DEF
sequence_2: CALIB2
targname: DARK
config: FOC/96
opmode: IMAGE
aperture: 512X1024
sp_element: F120M
num_exp: 1
time_per_exp: 8 M
fluxnum_1: 1
priority: 1
!
linenum: 11.000
sequence_1: USE
sequence_2: CALIB1
req_3: SEQ 11-78 WITHIN 7.0 H;
req_4: SEQ 11-18 WITHIN 98 M;
req_5: CALIB FOR 12; SEQ 11-18 NO GAP;
!
linenum: 12.000
targname: GLOW-TAR
config: WFC
opmode: IMAGE
aperture: ALL
sp_element: F850LP
num_exp: 3
time_per_exp: 8 M
priority: 1
param_1: SUM=2X2,
param_2: PRE-FLASH=YES
req_1: NON-INT;
req_2: GUIDE TOL 6.0"
comment_1: CRITICAL SCHEDULING REQUIREMENTS;
comment_2: SEE GF QUESTION 5; FIRST EXPOSURE
comment_3: SHOULD BE SCHEDULED IMMEDIATELY
comment_4: AFTER SPACECRAFT ENTERS EARTH
comment_5: SHADOW. PCS MODE GYRO.
!
linenum: 18.000
sequence_1: USE
sequence_2: CALIB1
req_1: CALIB FOR 12;
!
linenum: 31.000
sequence_1: USE
sequence_2: CALIB1
req_1: SEQ 31-38 WITHIN 98M;
req_2: CALIB FOR 32; SEQ 31-38 NO GAP;
!
linenum: 32.000
targname: GLOW-TAR
config: WFC
opmode: IMAGE
aperture: ALL
sp_element: F702W
num_exp: 3
time_per_exp: 8 M
priority: 1
param_1: SUM=2X2,
param_2: PRE-FLASH=YES
req_1: NON-INT;
req_2: GUIDE TOL 6.0"
comment_1: CRITICAL SCHEDULING REQUIREMENTS;
comment_2: SEE GF QUESTION 5; FIRST EXPOSURE
comment_3: SHOULD BE SCHEDULED IMMEDIATELY
comment_4: AFTER SPACECRAFT ENTERS EARTH
comment_5: SHADOW. PCS MODE GYRO.
!
linenum: 38.000
sequence_1: USE
sequence_2: CALIB1
req_1: CALIB FOR 32;
!
linenum: 51.000
sequence_1: USE
sequence_2: CALIB1
req_1: SEQ 51-58 WITHIN 98M;
req_2: CALIB FOR 52; SEQ 51-58 NO GAP;
!
linenum: 52.000
targname: GLOW-TAR
config: WFC
opmode: IMAGE
aperture: ALL
sp_element: F555W
num_exp: 3
time_per_exp: 8 M
priority: 1
param_1: SUM=2X2,
param_2: PRE-FLASH=YES
req_1: NON-INT;
req_2: GUIDE TOL 6.0"
comment_1: CRITICAL SCHEDULING REQUIREMENTS;
comment_2: SEE GF QUESTION 5; FIRST EXPOSURE
comment_3: SHOULD BE SCHEDULED IMMEDIATELY
comment_4: AFTER SPACECRAFT ENTERS EARTH
comment_5: SHADOW. PCS MODE GYRO.
!
linenum: 58.000
sequence_1: USE
sequence_2: CALIB1
req_1: CALIB FOR 52;
!
linenum: 71.000
sequence_1: USE
sequence_2: CALIB2
req_1: SEQ 71-78 WITHIN 98 M;
req_2: CALIB FOR 73; SEQ 71-78 NO GAP;
!
linenum: 73.000
targname: GLOW-TAR
config: FOC/96
opmode: IMAGE
aperture: 512X1024
sp_element: F120M
num_exp: 10
time_per_exp: 50S
priority: 1
req_1: NON-INT;
comment_1: CRITICAL SCHEDULING REQUIREMENTS;
comment_2: SEE GF QUESTION 5; FIRST EXPOSURE
comment_3: SHOULD BE SCHEDULED IMMEDIATELY
comment_4: AFTER SPACECRAFT ENTERS EARTH
comment_5: SHADOW. PCS MODE GYRO.
!
linenum: 78.000
sequence_1: USE
sequence_2: CALIB2
req_1: CALIB FOR 73;
!
! end of exposure logsheet
! No scan data records found