Valeport MIDAS Surveyor, Operation Manual

Page: 17 / 47

© Valeport Limited 2003
MIDAS Surveyor Operating Manual Page 17
0420805d.doc
4.2.5 OUTPUT SETUP
The MIDAS Surveyor will output data in real time. You may choose which parameters to output, and a selection of
formats for each. For each parameter, use the up and down keys to scroll through the available formats detailed below
(and OFF), and Enter to confirm the selection.
Output All GPS
This is a shortcut to output GPS data in all available formats (
currently GGA and VTG only
).
GGA Format
$GPGGA,m1,m2,c1,m3,c2,d1,d2,f1,f2,M,f3,M,f4,d3*cc
where:
$GPGGA NMEA Identifier
m1 Current UTC time of position fix in hours, minutes and seconds (hhmmss.ss)
m2 Latitude component of position in degrees and decimal minutes (ddmm.mmmmmm)
c1 Direction of latitude N= North, S= South
m3 Longitudinal component of position in degrees and decimal minutes (dddmm.mmmmmm)
c2 Direction of longitude E = East, W= West
d1 Position type: 0. Invalid or not available
1. Autonomous (uncorrected) position
2. RTCM or SBAS differentially corrected
d2 Number of satellites used in position computation
f1 Horizontal dilution of precision (HDOP)
f2 Altitude in meters above the reference ellipsoid. For 2-D position computation, this item contains the user- entered
altitude used to compute the position computation.
M Altitude units M = meters
f3 Geoidal separation in meters
M Geoidal separation units M = meters
d3 Age of differential corrections (seconds)
d4 Base station ID (RTCM only)
cc checksum
Example:
$GPGGA,015454.00,5233.9007,N,00358.7360,E,2,11,03.8,+70.000,M,-030.000,M,005,0000,*75
VTG Format
$GPVTG,f1,T,f2,M,f3,N,f4,K,c5*cc
where:
f1 COG (Course Over Ground) true north
T COG orientation (T = true north)
f2 COG magnetic north
M COG orientation (M = magnetic north)
f3 SOG (Speed Over Ground)
N SOG units (N = knots)
f4 SOG (Speed Over Ground)
K SOG units (K = Km/hr)
c5 Mode indicator: A = autonomous
D = differential
E = estimated (dead reckoning)
M = manual input
S = simulator
N = data not valid
*cc checksum
Example:
$GPVTG,300.00,T,300.00,M,004.50,N,009.01,K,D,*46