xbit70

Hi...I have a problem with antenna GPS, is a SIRF III, connected through USB to the software centrafuse that it uses destinator for navigator, employs too much time to couple the satellites, but once taken goes well (even if sometimes lost the signal but after it resumes it)but when i within the car in garage and then I resume it the defect returns, I have tried also with gpsgate, and I have the spread problem, in this case the icon of the software remains yellow signaling bad reception…. how I can resolve?

2k1Toaster

GPS receivers take different time to lock depending if they are "cold" or "hot". Cold means that they have been off with no power for a while. Hot means that it has been on and locked very recently.

One solution (used in OEM systems I believe), is to keep the GPS unit powered. If it is USB, then take the +/- wires and send constant 5v/0v even when the car is off. So if you have a DC-DC, then you could just set the smart controller to never hard off.

The other would be to put it out in the open. Like ontop of your roof. The better the line of sight, the better the signal lock time.

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xbit70

Hi...the problem is that the signal them comes lost
also with the car in motion and it passes from 12 satellites to zero in a moment,
also with antenna outside from car..

2k1Toaster

Where do you live?

GPS depends on satellites rotating above you. If you live too far out of their footprint, then you wont be able to get coverage. For instance there are a plethora of GPS sats above north america, but in Europe you can count them on 1 hand for GPS. The galilleo system though (if they ever finish it) will cover the EU and Asia much better.

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xbit70

thanks for the answers…
however I live in Italy, but my friends have a portable gps and they do not have a problem with the reception ...even if my antenna gps is 10 times more powerful of theirs..