Gene and Danny:

Here is the time line for the MEX BSR on day 224 (local time Wednesday 06:45
AM to 12:00 noon) at DSS 63.

This experiment is like many others we have done recently.  But it is very
short and almost nothing happens in terms of FROs and signal dynamics.  The
surface echo starts well above the carrier and drifts slowly upward for about
27 minutes.  Then it reverses direction and starts back down.  But the total
upward drift is only about 3 kHz at X-Band and the total drift down is less
than 1 kHz.

We start (16:43) with an incidence angle about 53 deg, so LCP will be
stronger than RCP.  The spacecraft is at high altitude (slant range to the
target about 8000 km) and the reflecting region is in cratered terrain west
of Syrtis Major (17N, 53E).  The reflecting region drifts slowly southwest
through more cratered terrain and we end at (3S, 45E) where incident angle is
61 deg (with RCP approximately equal to LCP) and slant range is 5500 km.

There appears to be plenty of time to do both Mini-Cals, changes in ground
antenna pointing, etc.

For playback, I recommend the following for the 25 kHz data (no segment
longer than 88 minutes):

       Pre-cal
       Track until start of 100 kHz data
       Surface until end of 100 kHz data
       Remaining track (MINICAL #2) and post-cal

For 100 kHz playback a 17 minute segment followed by a 20 minute segment
works.  This puts the break on the hour (17:00).

I expect to be in Palo Alto for this experiment.  Try my home number (650-
494-9272) during the early part or the lab (650-723-3525 later, if you need
to call.


Thanks,
Dick




2010/224 (UTC)
- - - - - - -

13:45  Begin Pre-cal at DSS 63
       FGAIN = 60 dB (all channels, except X-RCP)
               65 dB X-RCP
       FRO_X = 0; FRO_S = 0 (all SCHAN)
       Start 4-channel 25 kHz recordings after Step 5 (new NOP)
       Stop 25 kHz recording after Step 20 (new NOP)

15:45  Begin track
       X-Band AOS (probably with low priority telemetry)

15:47  S-Band AOS

16:02  X-Band telemetry OFF

16:03  Resume 25 kHz recording

16:10  Advise DSS 63 of switch to planetary coordinates at 16:18
       Advise DSS 63 of start of MINICAL #1 at 16:22

16:14  Begin SLEW #1

16:18  DSS 63 switch to planetary coordinates

16:20  FRO_X = +38000 Hz (SCHAN 3)
       FRO_S =  +5000 Hz (SCHAN 3)

       FRO_X = +20000 Hz (SCHAN 4)

16:22  Begin MINICAL #1

16:37  End of MINICAL #1 (end of step 5)

16:43  End SLEW #1

       Begin 100 kHz recording (SCHAN 4)

17:10  Maximum upward drift of echoes

17:15  Advise DSS 63 that MINICAL #2 begins at 17:23
       Advise DSS 63 to return to spacecraft pointing at 17:39

17:20  Begin SLEW #2 back to Earth

       End 100 kHz recording (SCHAN 4)

17:23  Begin MINICAL #2

17:38  End MINICAL #2 (end of step 5)

17:39  DSS 63 return to spacecraft pointing

       FRO_X =      0 Hz (SCHAN 3)
       FRO_S =      0 Hz (SCHAN 3)

17:40  End SLEW #2

17:47  S-Band LOS
       X-Band telemetry ON (ignore)

       Early end of track (scheduled for 18:00)
       Go to zenith
       Begin post-cal when ready

19:00  End post-cal (or earlier, if post-cal complete)

       End 25 kHz recordings

       End of Activity