IPAC_ATT data format
This format is applicable to the release after March 6, 1996File Header (5 lines)
\ Reconstructed Attitude File (IPAC- Phase I) \ |date-time |LAUNCHtime |ra_sts |dec_sts |sigi|sigx|posang |sigpa |FPang |sFPang |ra_bs |dec_bs |s1bs|s2bs|pa_bs |spa_bs |packet |qflag |spare | |double |double |double |double |d |d |double |double |double |double |double |double |d |d |double |double |char |int |char | |mmddhhmmss.sss|seconds |deg |deg |amin|amin|deg |deg |deg |deg |deg |deg |amin|amin|deg |deg | | | | 0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6(note: The last two lines are only scale, not header.)
Program codes for reading the ipac_att data:
Fortran
integer*4 month, day, hour, minute
real*8 seconds
real*8 time, ra_sts, dec_sts, sigin_sts, sigx_sts, pa_sts,
real*8 sig_pa_sts, fp_ang, sig_fp_ang, ra_bs, dec_bs,
real*8 sigin_bs, sigx_bs, pa_bs
integer*4 numpacket, qflag(15)
character*6 spare
read("ipac_att_lan", 100) month, day, hour, minute, seconds,
time, ra_sts, dec_sts, sigin_sts, sigx_sts, pa_sts,
& sig_pa_sts, fp_ang, sig_fp_ang,
& ra_bs, dec_bs, sigin_bs, sigx_bs, pa_bs, sig_pa_bs, numpacket,
& qflag, spare
100 format(1x, 4i2, f6.3,
& f12.3, 2f9.4, 2f5.1, f9.4,
& f8.4, f9.4, f8.4,
& 2f9.4, 2f5.1, f9.4, f8.4, i8, 1x, 15i1, 1x, a6)
IDL
s = {ipac_att_struct, $
mon:0, day:0, hour:0, min:0, sec:0., $
ltime:0d, $
ra_sts:0., dec_sts:0., $
sigi:0., sigx:0., $
pa_sts:0., spa_sts:0., $
fp_ang:0., sfp_ang:0., $
ra_bs:0., dec_bs:0., $
sbsi:0., sbsx:0., $
pa_bs:0., spa_bs:0.,$
packet:' ', $
qflag:bytarr(15), $
spare:' ' }
ipac_att = replicate(s, n)
readf, 1, ipac_att, $
format='(1X,4I2,F6.3,F12.3,'+$
'2F9.4,2F5.1,F9.4,F8.4,F9.4,F8.4,'+$
'2F9.4,2F5.1,F9.4,F8.4,1X,A7,1X,15I1,1X,A6)'
Top of this pageDefinition of Variables
| date-time | = | month (mm), day(dd), hour(hh), minute(mm), second(ss.sss) |
|---|---|---|
| LAUNCHtime | = | time in seconds since launch (95-03-18 08:01:00 UT) |
| ra_sts | = | reconstructed right ascension (B1950) of STS lower right corner as seen in Figure 7 of Murakami et al. (1994, ApJ, 428, 354) This point is labeled "C2" in the memo on the theodolite measurements of the relative positions of the four corners of each FPI |
| dec_sts | = | reconstructed declination (B1950) of STS lower right corner |
| sigi | = | twice the standard deviation of the in-scan reconstruction (for the star sensor data) (for Nov. 1995 release, this is set equal to 1' for all times except in the gyro settling periods after an orbital event. In those intervals, this is set to 30') |
| sigx | = | twice the standard deviation of the cross-scan reconstruction (for the star sensor data) (for Nov. 1995 release, this is set equal to 2' for all times except in the gyro settling periods after an orbital event. In those intervals, this is set to 30') |
| posang | = | angle defining in-scan direction (east of north B1950). (this is 90 deg off from the positional uncertainty ellipse position angle for the star sensor data if sigx > sigi, and equal to the error ellipse position angle if sigi > sigx.) |
| sigpa | = | standard deviation of position angle for the star sensor position (in Nov. 1995 release, this is not calculated, but is set to zero) |
| FPang | = | the angle between the assumed in-scan direction according to the nominal focal plane orientation (Figure 1) and the actual in scan direction (in Phase 1, not reconstructed, but assumed equal to 0 deg) |
| sFPang | = | standard deviation of the FPangle (not calculated in Phase 1; set equal to zero) |
| ra_bs | = | ra of boresight (in Phase 1, calculated using FPang = 0 deg) This is calculated using the theodolite measurements of the distance between the nominal boresight to the STS lower left corner. These measurements are 0.1083 degrees in in-scan direction and -1.05 degrees in cross-scan direction. |
| dec_bs | = | dec of boresight (in Phase 1, calculated using FPang = 0 deg) This is calculated using the theodolite measurements of the distance between the boresight to the STS lower left corner. |
| sbsi | = | in-scan uncertainty of the boresight position (in Phase 1, this is calculated using sigi, assuming an additional systematic uncertainty of 1' due to the uncertainty in the C2-boresight distance.) |
| sbsx | = | cross-scan uncertainty of the boresight position (in Phase 1, this is calculated using sigi, assuming an additional systematic uncertainty of 1' due to the uncertainty in the C2-boresight distance.) |
| pa_bs | = | position angle of the boresight error ellipse (east of north B1950) (in Phase 1, this is set equal to posang) |
| spa_bs | = | standard deviation of the position angle for boresight uncertainty ellipse (in phase 1, assumed equal to sigpa) |
| packet | = | packet number of concatenated input ATT_LAN and IRTS_LAN files |
| qflag | = | quality flags (below) |
| dummy | = | reserved for future use |
digits of quality flag parameter (1 corresponds to the leftmost digit):
| 1 | = | Did Not Match Flag | => | Did Not Match STS Stars in this Time Interval |
|---|---|---|---|---|
| 2 | = | Thruster Flag | => | Thruster Mode |
| 3 | = | Bad/Missing Data Flag | => | Bad/Missing Data |
| 4 | = | Bad Gyro Flag | => | Bad Behavior of Gyros |
| 5 | = | Aperture Cover Flag | => | Aperture Cover On |
| 6 | = | STS off Flag | => | Star Sensor Off |
| 7 | = | G Angle Flag | => | G Angle Change |
| 8 | = | Spin Rate Flag | => | Commanded Spin Rate Change |
| 9 | = | Moon Flag | => | Moon Dominates Star Sensor Data |
| 10 | = | Split Packet Flag | => | Segment Split Between 2 Packets |
| 11 | = | Low Latitude Flag | => | Low Latitude Scan (before flip) |
| 12 | = | Pt D to Eclipse In Flag | => | During Pt. D to Eclipse In |
| 13 | = | Eclipse In to Eclipse Out Flag | => | During Eclipse In to Eclipse Out |
| 14 | = | Eclipse Out to Point D Flag | => | During Eclipse Out to Pt. D |
| 15 | = | Could Not Fit Flag | => | Problem Fitting STS Stars in this Time Interval |
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Last modified: Sep 30, 1997