Iapetus rev 49 requests: ISS_049IA_ORSHIRES001_VIMS

Trigger 2905 – Big Turn About Y, Transition Zone

Update: 09 Aug 2007 (TD)

Secondary axis: Start at: NEG_X to Iapetus SC_RAM; end at: NEG_X to NorthPoleDir

Spatial resolution (NAC 2sum) = 45 and 53...56 m/pxl;  (WAC) 226 ... 282 m/pxl

GMB_E049_Iapetus = 2007-253T14:15:40

Offset from first tracking period (for trigger start): 1:08:08 h

Geometry:

    UTC             ALTITUDE  SC_LAT   SC_LON   Sun_LAT  Sun_LON  PHASE

2007 SEP 10 14:39:01    3311   -10.1    210.4       1.4    214.5   13.2

2007 SEP 10 14:42:57    3773   -10.3    214.6       1.4    214.5   12.8

2007 SEP 10 14:46:53    4255   -10.4    218.0       1.4    214.5   13.4

2007 SEP 10 14:47:52    4378   -10.4    218.8       1.4    214.5   13.6

2007 SEP 10 14:48:14    4424   -10.4    219.1       1.4    214.5   13.7

2007 SEP 10 14:48:36    4470   -10.4    219.3       1.4    214.5   13.8

2007 SEP 10 14:48:58    4516   -10.4    219.6       1.4    214.5   13.9

2007 SEP 10 14:49:20    4562   -10.4    219.8       1.4    214.5   14.0

2007 SEP 10 14:50:04    4655   -10.4    220.3       1.4    214.5   14.2

2007 SEP 10 14:50:26    4701   -10.4    220.6       1.4    214.5   14.3

2007 SEP 10 14:54:45    5256   -10.4    223.2       1.4    214.5   15.6

Goals: - Secondary axis turn to avoid sun radiator violation
- High-res. (NAC and WAC) mid-latitude transition zone imaging

Pointing (pdt issues):
- Turn start UTC: 2007-253T14:39:01 (IA+00:23:21 h)
- Turn duration: 15:44 min.
- Turn end UTC: 2007-253T14:54:45 (IA+00:39:05 h)
- Turn start and end locations (lat/lon): -12/168; -43/209
- Use dummy tracking sfof and ck files for feeding ISSPT

Exposures (ISSPT issues):
- ISSPT data volume: 32.9 Mb
- 1x8 clr NAC 2sum 12 bit mosaic plus two more ftprts in BOTSIMs
- 1x3 clr WAC LUT mosaic (= 1x4 with trigger 2906)
- Time table:   

  Cam  Shutter  prep   Frame      Cum.time   wait time

  BOT  14:42:57 -13s = 14:42:44 = 03:43 min  ^{Wait1 = 3:43}
  WAC  14:46:53 – 5s = 14:46:48 = 07:46 min  ^{Wait2 = 2:47}
  NAC  14:47:52 – 4s = 14:47:48 = 08:46 min  ^{Wait3 = 0:05}
  NAC  14:48:14 – 4s = 14:48:10 = 09:08 min  ^{Wait4 = 0:05}
  NAC  14:48:36 – 4s = 14:48:32 = 09:30 min  ^{Wait5 = 0:05}
  NAC  14:48:58 – 4s = 14:48:54 = 09:52 min  ^{Wait6 = 0:05}
  NAC  14:49:20 – 4s = 14:49:16 = 10:14 min  ^{Wait7 = 0:05}
  NAC  14:49:42 – 4s = 14:49:38 = 10:36 min  ^{Wait8 = 0:05}
  NAC  14:50:04 – 4s = 14:50:00 = 10:58 min  ^{Wait9 = 0:05}
  BOT  14:50:26 – 5s = 14:50:21 = 11:19 min  ^{Wait10= 0:04}

Notes: Cam = Camera; Shutter = desired shutter UTC; prep = camera prepare time;
         Frame = frame start UTC; Cum.time = cumulative time info in ISSPT

Exposure times:
- NAC clr (2sum, 12 bit): 35ms (g=2)
- WAC clr: 15ms (LUT)

Smear calculation:
~230 km max. slew within ~190s => "smear speed" ~1.2 km/sec = 27m / 22.5ms (25ms exp.),
while NAC res. ~25 m/pxl (fullres.)