GPS Receiver User Manual

Copernicus GPS Receiver 129
TRIMBLE STANDARD INTERFACE PROTOCOL (TSIP) A
Key Setup Parameters or Packet BB
Selecting the correct operating parameters has significant impact on receiver
performance. Packet 0xBB (set receiver configuration) controls the key setup
parameters.
The default operating parameters allow the receiver to perform well in almost any
environment. The user can optimize the receiver to a particular application if the
vehicle dynamics and expected level of obscuration are understood. If the receiver is
then taken out of this environment, the specifically tuned receiver may not operate as
well as a receiver with the default options
Table A.10 Key Setup Parameters or Packet BB.
The default values in Table A.10 allow the receiver to operate well under the most
varied and demanding conditions. A user may choose to change the default
parameters if the receiver is only required to perform in a specific or limited
environment. The user should be warned that when the receiver is exposed to
operating conditions which are different from the conditions described by the user
setup, then the performance may be degraded.
Initially, the user must consider the environment in which the receiver is expected to
operate. There is a trade-off between how frequently a position fix is output versus
the absolute accuracy of the fix. The user must decide which takes priority and then
make the appropriate selections. This becomes increasingly important when frequent
satellite blockages are expected, as in downtown “urban canyon” environments and
heavily foliated areas.
Following is a description of the key fields in Packet 0xBB.
Dynamics Code
The feature default is LAND mode, where the receiver assumes a moderate dynamic
environment. In this case, the satellite search and re-acquisition routines are
optimized for vehicle type environments. In SEA mode, the search and re-acquisition
routines assume a low acceleration environment. In AIR mode, the search and re-
acquisition routines are optimized for high acceleration conditions.
Parameter Factory Default
Dynamics code Land
Elevation mask 5°
SBAS on/off WAAS_Auto