Connect a GPS

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Follow the manufacturer’s instructions to connect the GPS. If it uses a USB connector then you will probably need to install some software drivers. Do this before starting Nuno.

Connect a GPS to Nuno Navigator so as to monitor the position of your boat. You can connect your GPS before or after Nuno Navigator has started.

Nuno Navigator only processes NMEA 0183 and your GPS must be capable/configured to this interface.

Once the GPS has been connected for a little while Nuno Navigator will automatically find your GPS. This may take anything up to three minutes. The next time that you start Nuno Navigator it will find your GPS almost instantly - so long as you have not altered your GPS settings and it is still connected correctly.

Display the Route Monitor using the Show button.

Observe the GPS symbol in the bottom right of the Route Monitor Window.

Image:ConnectGPS_Step1.png Nuno Navigator is scanning all available inputs looking for NMEA data. It will stop when it finds some.
Image:ConnectGPS_Step2.png NMEA data is being received and the positions being received are of good quality and are referenced to the correct Horizontal Datum (WGS84). The boat is being plotted on the chart using these positions. This is what you hope will be displayed most of the time.
Image:ConnectGPS_Step3.png NMEA data has been received recently, but is of poor quality. Treat positions as possibly suspect. The boat is being plotted on the chart using these positions.
Image:ConnectGPS_Step4.png NMEA data has been received in the past, but is of very poor quality. Positions of the boat on the chart are being plotted assuming a constant speed and bearing from the last known good position.

The tip displayed when the cursor is over the GPS status symbol contains the following elements:

Element Purpose Possible Values Meaning of Value
Position Quality An overall indicator of the reliability of the GPS positions Recent All working correctly
Dead Reckoning No longer receiving positions
Unknown No positions have ever been received
HDOP Horizontal Dilution Of Precision. A numeric measure of the quality of the GPS positions 1.0 – 3.0 Excellent
3.0 – 5.0 Reasonable
5.0 – 10.0 Moderate to Poor. A more open view of the sky is recommended.
10+ Very poor. Positions are suspect
No. Satellites in use 0 – 12 Typically 5 or more is good
Horizontal Datum The Horizontal Datum used by the GPS for positions WGS84 GPS correctly configured
Not WGS84 GPS not configured correctly. Reconfigure it
Unknown GPS not capable of telling Nuno Navigator whether it is configured correctly

If you change any settings on your GPS (e.g.: Baud rate), Nuno Navigator will automatically rediscover your GPS for you and no action needs to be taken on your part. If you unplug/plug your GPS Nuno Navigator will also automatically rediscover your GPS for you.

Also see Troubleshoot the GPS input.

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