M e r i d i a n I I U s e r M a n u a l
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C H A P T E R T H R E E
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M e r i d i a n I I U s e r M a n u a l
C O N T R O L A N D S T A T U S C O M M A N D S
gpslastfix
This command provides the last computed GPS position. When tracking four or more satellites, the
GPS Receiver may provide a 3D-position fix, otherwise an overdetermined time-only solution will be
computed. The last-fix position is unaveraged and typically less accurate than the reference posi-
tion, but it does provide a good indication that the receiver is working properly. Position is provided
in latitude, longitude and height above the WGS-84 ellipsoid. PDOP, HDOP, VDOP and TDOP are
also shown. OORCnt is the out-of-range counter which may be non-zero when Meridian II has been
moved more than 1 km from its previous location without being placed in UNKNOWN mode using
the
setgpsrefpos
command. It could also be non-zero during a GPS system anomaly, in which
case Meridian II TRAIM algorithms will be operating to maintain the integrity of the system timing.
Command:
gpslastfix
MeridianII reply:
LAST POSITION FIX = N38d24m54.33s W122d45m10.99s +00003.5 meters
PDOP: 2.90 HDOP: 1.48 VDOP: 2.49 TDOP: 2.03 OORCnt: 0
gpsrefpos
This command displays the current GPS Subsystem reference position. The source of the position,
which is one of UNK (unknown), DYN (dynamic), USR (user entered) or AVG (24 hour average of
GPS fixes) is displayed first. The WGS-84 latitude and longitude in degrees, minutes, seconds format
and the height above the WGS-84 reference ellipsoid in meters follow. Also, the current RMS PDOP
of the average position and the current count of averages are shown. If the reference position source
is not AVG, then these two values will be zero.
Command:
gpsrefpos
MeridianII reply:
CURRENT REFERENCE POSITION = AVG N38d24m54.30s W122d45m10.95s +00004.1 meters
RMSPDOP: 2.4 AvgCnt: 28800
gpsrefpos_ecef
This command displays the current GPS Subsystem reference position in Earth-Centered Earth-Fixed
format. The source of the position, which is one of UNK (unknown), DYN (dynamic), USR (user
entered) or AVG (24 hour average of GPS fixes) is displayed first. The WGS-84 X, Y, Z coordinates
in meters are displayed next. Then, the current RMS PDOP of the average position and the current
count of averages are shown. If the reference position source is not AVG, then these two values will
be zero.
Command:
gpsrefpos_ecef
MeridianII reply:
CURRENT REFERENCE POSITION ECEF = AVG X: -2707225.0 m Y: -4208361.2 m Z: +3941650.2 m
RMSPDOP: 2.4 AvgCnt: 28800
gpsstat
This command allows you to query the status of the GPS Subsystem. During normal operation,
the system polls the GPS Subsystem every 10 seconds. The results of this poll are used to steer the
system clock and are saved to a log file. This command parses and formats the data contained therein
and prints this fixed-length string having these fields:
Summary of Contents for Meridian II
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