Gps Parameters - Sensors & Software Noggin 100 User Manual

13-Survey & Map Mode

13.3.5 GPS Parameters

The Global Positioning System (GPS) uses special satellites around the Earth to determine the
position of a GPS receiver located at any position on the surface of the Earth. GPS receivers can
be purchased from a number of manufacturers.
The DVL has a serial port on the back for attaching a GPS receiver (9: p.44). This port will
accommodate any GPS receiver that has a standard serial port output.
The GPS receiver can be set up to send one or more types of data strings to the DVL. These
strings are called NMEA-0183 strings and each contains positional or other information in
specific formats. Each type of string is specified by a 5-character prefix. There are numerous
NMEA strings but to integrate the GPS data into the Noggin data, the GPS must be sending at
least one of the following NMEA strings: GPGGA, GPGLL and GPRMC.
GPS information is logged while collecting Noggin data. The GPS information may be useful for
mapping where GPR surveys have been performed or determining where a specific target of
interest is located in GPS co-ordinates.
The DVL can be set up to read and log GPS information collected during data acquisition with the
Noggin system. GPS information can be logged in two different ways:
1) For every trace collected by the Noggin system, or
2) Every time the user adds a fiducial to the data by pressing the A button (13.2.4.2:
p.80).
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