Gene and Danny:

Here is the time line for tomorrow's MEX BSR: days 106-107 (local time 16
April 11 AM to 7 PM) at DSS 63.

The surface observations start at (15S, 35W) and end at (34S, 50W); this
appears to be a transition region between cratered terrain north of Argyre
Planitia, which we have probed in several recent experiments, and smoother
material around Valles Marines.  The spacecraft goes through apoapsis about
40 minutes before we start recording surface echoes, so everything happens
slowly and signals are relatively weak.  Mars is also farther away than in
February, which also doesn't help.  Incidence angle on the surface varies
from 32 to 50 degrees, meaning LCP should be stronger than RCP throughout but
with RCP making gains toward the end - the same as in the previous three
experiments but with slightly more of a bias toward LCP.

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 observations until end of 100 kHz data
       Remaining track plus post-cal

For 100 kHz playback three 21 minute segments and one 20 minutes segment
would be fine; but I can carve these up at Stanford if you give me an 83
minute file from each RSR.

I will be on the road Friday (in fact for most of the next week).  I'll plan
to give you a call at strategic times; and I'll give you a number where you
can reach me if that makes any sense ... I'm not sure what that number will
be right now.

Thanks,
Dick


2010/106 (UTC)
- - - - - - -

18:00  Begin Pre-cal at DSS 14
       FGAIN = 60 dB (all channels, including 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)

20:00  Begin track (S- and X-Band should both be OFF)

20:18  X-Band ON, telemetry should be ON - ignore it

20:50  S-Band ON

21:06  Resume 25 kHz recording

       Advise DSS 63 of switch to planetary coordinates at 21:21

21:17  Begin SLEW #1

21:21  DSS 63 switch to planetary coordinates

21:23  FRO_X = +24000 Hz (SCHAN 3)
       FRO_S =  +5000 Hz (SCHAN 3)

       FRO_X = +25000 Hz (SCHAN 4)

21:25  Begin MINICAL #1

21:40  End of MINICAL #1 (end of step 5)

21:43  End SLEW #1

       Begin 100 kHz recording (SCHAN 4)

22:01  FRO_X = +31000 Hz (SCHAN 3)

22:20  FRO_X = +38000 Hz (SCHAN 3)

22:40  FRO_X = +45000 Hz (SCHAN 3)

23:00  Advise station of MINICAL #2 starting at 23:08 and
       Advise station of return to S/C pointing predictions at 23:23

23:06  End 100 kHz recording (SCHAN 4)

       FRO_X = +24000 Hz (SCHAN 3)

       Begin SLEW #2

23:08  Begin MINICAL #2

23:23  End MINICAL #2 (end of step 5)

       DSS 63 return to spacecraft pointing predicts

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

       End SLEW #2

23:40  X-Band telemetry ON

23:46  X-Band LOS
       S-Band LOS

       Early end of track (scheduled EOT 01:00)

       Go to zenith

       Begin post-cal when ready

2010/107

02:00  End post-cal (or earlier, if post-cal complete)

       End 25 kHz recordings

       End of Activity