17-4 Setup > GPS
Press 
twice, then select GPS:
GPS Source
•NMEA: Use the external GPS antenna supplied or an external GPS or DGPS source connected via NMEA (see section
•NavBus: Use an external GPS or DGPS source connected via NavBus (see section
DGPS Source
Enables or disables the satellite based DGPS correction (see section 7). The options are None or WAAS/EGNOS. Do not enable WAAS/EGNOS outside their coverage areas or the accuracy of the position might be degraded.
WAAS covers all of the USA and most of Canada. To use WAAS, the GPS antenna must have a clear view of the sky towards the equator. EGNOS will cover most of Western Europe when it becomes operational.
Restart GPS
Restarts the internal GPS receiver for servicing or troubleshooting. The GPS receiver takes up to three minutes to restart. The satellite window
shows the status of the GPS receiver (see section 7). Restart the GPS if the receiver has not been used for some time and is taking a long time to get a GPS fix.
Static Navigation
When the boat stops or moves very slowly, the calculated GPS speed and course become erratic. Static navigation allows the erratic values to be filtered:
•0.01 to 99.9: If the boat speed is slower than this, the speed is displayed as zero and the course stays unchanged.
•0 (Off): The calculated speed and course are always used.
Speed and Course Filter
Waves and wind cause the boat speed and course to fluctuate slightly. To give stable readings, the 657 calculates these values by taking several measurements and averaging them.
A lower value averages measurements over a shorter period of time. This gives the most accurate value but has the most fluctuations.
A higher value averages measurements over a longer period of time. This gives the most stable value but will ignore some [true] sudden speed changes.
Set the Speed and Course filters to the lowest values which give stable readings. The range of each filter is 1 to 60 seconds or Off (0).
17-5 Setup > Fuel
! WARNING
Fuel consumption can change drastically depending upon the boat loading and the sea conditions. Always carry adequate fuel for the journey, plus a reserve.
Fuel functions require optional fuel flow sensors to
be installed. Press 
twice, then select Fuel:
66 | Northstar Explorer 657 Installation and Operation Manual |
