Gene and Danny:

Here is the time line for the MEX BSR on day 111 (Friday 12:45 to 06:45 PM at
JPL) using DSS 63.

This is a very long surface observation (almost 90 minutes) starting at high
altitude and ending just before periapsis.  The ground track starts at (20N,
146E) near Elysium Mons, then drifts southward across featureless volcanic
plains.  At about 5S it passes just outside Gale Crater (the MSL target),
then enters southern cratered highlands drifting more rapidly both east and
south.  At (60S, 164W) it starts northward again, ending at (45S, 122W) about
5 minutes before periapsis.

The X-Band surface echo begins 37 kHz above the carrier with LCP stronger,
moves about 4 kHz higher over the first 30 minutes, then returns to its
original position after another 20 minutes (and after passing Gale where LCP
and RCP should be about equal).  RCP gains relative to LCP and the echo
drifts more rapidly toward lower frequencies.  However, the first FRO_X is
almost an hour into the observation.  There is then a FRO_X about every 5
minutes for the rest of the observation.  The surface echo passes through the
carrier about 2 minutes before the end; the incidence angle is almost 85 deg
at that point, so RCP will be very narrow and there will be almost nothing in
LCP.

There are several 25 kHz X-Band FROs, one 25 kHz S-Band FRO, and one 100 kHz
X-Band FRO for surface observations.  There is a large FRO at both S- and X-
Band before MINICAL #2 because SLEW #2 is so short.  I donÕt think we will
need an FGAIN change for the strong X-Band carrier; but you should keep an
eye open for possible clipping.

IÕll plan to be in the lab at Stanford (650-723-3525) for the experiment.

Thanks,
Dick


2012/111 (UTC)
- - - - - - -

19:45  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 18 (new NOP)

21:45  Begin track
       X-Band AOS (with ranging and low priority telemetry)
       S-Band AOS (carrier only)

21:53  X-Band telemetry OFF

       Resume 25 kHz recording

21:55  Advise DSS 63 of switch to planetary coordinates at 22:00
       Advise DSS 63 of start of MINICAL #1 at 22:13

22:00  DSS 63 switch to planetary coordinates

22:05  Spacecraft begins SLEW #1

22:08  FRO_X = +31000 Hz (SCHAN 3)
       FRO_S =  +4000 Hz (SCHAN 3)  (S-Band)
       FRO_X = +20000 Hz (SCHAN 4)

22:13  Begin MINICAL #1

22:28  End MINICAL #1 (end of step 5)

22:31  End SLEW #1

       Begin 100 kHz recording (SCHAN 4)

23:26  FRO_X = +24000 Hz (SCHAN 3)

23:34  FRO_X = +17000 Hz (SCHAN 3)

23:39  FRO_X = +11000 Hz (SCHAN 3)

23:44  FRO_X =  +4000 Hz (SCHAN 3)

23:49  FRO_X =  -2000 Hz (SCHAN 3)

23:55  FRO_X =  -6000 Hz  (SCHAN 3)

       Advise DSS 63 that MINICAL #2 begins at 00:03
       Advise DSS 63 of return to spacecraft pointing after MINICAL #2

23:59  End 100 kHz recordings (SCHAN 4)

       FRO_X = +60000 Hz (SCHAN 3)
       FRO_S = +60000 Hz (SCHAN 3) (S-Band)

2012/112 (UTC)
- - - - - - -

00:00  Begin spacecraft SLEW #2 back to Earth

00:03  Begin MINICAL #2

00:10  End SLEW #2 (not visible because of FRO)

00:18  End MINICAL #2 (end of step 5)

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

       DSS 63 return to spacecraft pointing (donÕt start before 00:18)

00:21  X-Band telemetry ON (ignore)

       S-Band LOS

       Early end of track (scheduled for 00:45)
       Go to zenith
       Begin post-cal when ready

01:45  End post-cal (or earlier, if post-cal complete)

       End 25 kHz recordings

       End of Activity