Sojourner Rover Telecom System Report for Sol 56

Report as of  August 30, 1997

Telecom system performance was nominal this sol. This area of the bookshelf seems to add considerable multipath effects to the telecom link. There are no telecom operational constraints for future rover operations.

The end-of-sol communication system performance for the downlink was as follows:

SOL 56 DOWNLINK TELECOM STATISTICS	
Rov Radio Temp Low =	-11.7
Rov Radio Temp High =	31.8
Rov Radio Temp Avg =	12.4
LMRE Radio Temp Low =	3.5
LMRE Radio Temp High =	19.6
LMRE Radio Temp Avg =	13.7
Rx Current Low =	43.5
Rx Current High =	78.3
Rx Current Avg =	49.1
Tx Current Low =	0.0
Tx Current High =	197.2
Tx Current Avg =	141.9
LMRE Good Frames =	1606
LMRE Garbled Frames =	1700
Avg LMRE Link Quality%=	48.6
TX_CH_FRAMES =	2002
RX_CH_FRAMES =	1950
Total Frame Resends =	52
Avg Rover Link Quality%=	97.4
COM:Bad CRC Errors =	1
COM:Timeout Errors =	40
COM:Rx Abort Errors =	4
COM:No Sync Errors =	0
COM:RX Com Errors =	332

In planning the sequence for Sol 57 and beyond, the revised modem heating strategy used should be followed:  

The rover modem should be commanded in the next-day runout sequence to perform a 600 second modem heating at wakeup.  If no overnight APXS operations are to be conducted, the wakeup rover modem heating should be extended to 900 seconds.  Modem reheating should be triggered by an excessive number of frame retries on the rover-to-lander link, and the reheating should continue for five minutes or until the rover modem reaches +30 C.  However, if the LMRE radio is off, then the reheat to get to +30C is not needed. Also, if there are afternoon only downlink sessions, then no modem heating is required after wakeup on solar. This requires some coordination of timing between the LMRE ON times and the rover transmissions.  The sequence planners should consider the uncertainty in event completion times introduced by any required modem reheating cycles.

Rover Telecom Team,

Scot L. Stride