Originally Posted by jimthom
Thank you for your help. I installed a program called VisualGPS and I think it is a faulty GPS receiver. It locks onto a particular long and lat and when I reset it, the long and lat will change a few thousandths of a minute every second about five times and then will again lock on to a specific long and lat. Yes, it did work with ver. 4.0 some time ago and the fault may have developed in the meantime. The signal strength of the satellite
display on VisualGPS is also changing every few seconds and that doesn't lock.
The really odd thing is that it records a track.
I recorded the data stream from VisualGPS
Since your GPS and OpenCPN
4.0 previously worked, but now the position does not change while you are anchored, it is likely that "static navigation" (SN) has been enabled for the GPS by some program. While SN is enabled in the GPS, whenever the GPS is moving very slowly, a constant latitude and longitude is sent in the NMEA
stream until the GPS moves by some "update threshold" distance (might be 50 meters). A new position will be reported each time the slowly moving GPS moves by the "update threshold".
I found the following link while looking through the VisualGPS.net website. The link contains a little more information on "static navigation".
GpsPasSion Forums - SiRFdemo tutorial (static navigation)
I don't know anything about the SiRFdemo program. It could be good, or it could be bad. It could harm your GPS or system.
If you have the original configuration program for your GPS you might be able to use it to disable the "static navigation" in order to restore continuous position updates.