GSSI SIR 4000, Руководство пользователя

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Geophysical Survey Systems, Inc. SIR® 4000
Manual
MN72-433 Rev F 131
9.3 What is the DZG File?
The GPS file collected with the SIR 4000 is identified by the extension *.DZG and consists of multiple
two-sentence blocks. First sentence (line) starting with $GSSIS contains the DZT file scan (trace number)
associated with the GPS location. Second sentence (line) starting with $GPGGA contains the GPS-
NMEA coordinate information.
$GSSIS sentence structure
Name Example Description
Message ID $GSSIS Fixed text identifier
File Scan # 0 File scan (trace) number, >=0
Scan Count* -1 When Pulse Per Second (PPS) is used on the GPS unit, this number is
the scan count at the specified scan rate from when the system was
started, >=0 (missing value = -1)
*The value in field 2 is convertible into seconds by subtracting the number from the value associated with
the $GSSIS record at Scan 0, then dividing by the scans/sec in the DZT file header.
How to Calculate the Time
To calculate the time relative to the start of the file for each scan record, determine the scan rate from the
DZT header, e.g., 473 scans per second. Following are three lines from a DZG file:
$GSSIS,0,1648470
$GPGGA,150523.00,4713.45783544,N,06817.11556267,W,2,10,1.0,185.873,M,-26.675,M,6.0,0138*76
$GSSIS,16,1648784
$GPGGA,150526.00,4713.46286086,N,06817.13084159,W,2,10,1.0,185.368,M,-26.675,M,3.0,0138*79
$GSSIS,42,1649257
$GPGGA,150527.00,4713.46473386,N,06817.13641152,W,2,10,1.0,185.206,M,-26.675,M,4.0,0138*7D
Scan Count at File Scan 0 = 1648470
Scan Count at File scan 16 = 1648784
Format:
$GSSIS,x,x
$GPGGA,hhmmss.ss,llll.ll,a,yyyyy.yy,a,x,xx,x.x,x.x,M,x.x,M,x.x,xxxx*hh
Example:
$GSSIS,0,-1