Thread: About 37xx converted to 34xx satellites reception accuracy

Originally Posted by Kanopus

Is it really a problem? I mean, could you define the problem without a reference to satellite screen? And get any evidence?

As for accuracy on satellite screen, using photoshop is an example of a working solution

I have had similar doubts, but googled and understood clearly that, yes, we have a problem. The values shown are not mere rates obtained directly from satellites that are shown on the screen, they are the result of complex calculations made ​​in gps. If we have the same hardware with distinct aparent accuracy on different firmwares and these values ​​represent coordinates position and other derivatives, all differents and fruits of calculations, then we have a problem.

I believe that nobody of good sense here has the illusion that these values ​​are absolute, true, far from it (but we have faith, lol). Our GPS navigation receive only raw data untreated of L1 frequency, and algorithms, database and processing capabilities of the device are unable to perfectly correct distortions of ionosphere, troposphere, orbit errors, timing, signal reflection between others. These distortions, experts say, can lead to errors of up to 10 meters, but we are not discussing the real accuracy that we could only achieve with our garmin if it could capture raw data from the satellites for later to be post-processed on servers with powerful software.
How much of distortion has the precision on the screen in relation to real coordinated, is another discussion, by the way, the path that we are following in forum of my country. But the issue here is another: we are in the battle for to try to get that the modified 3790 presents the same "accuracy" of the 3790 original, even if the 3 meter of the screen represent 50 meters in reality. If both gps work equally means they are doing their calculations properly as they were designed, and that has nothing to do with aesthetics, appearance or "photoshop", my friend ..

Finally, yes, you can set without reference screen satellite: just, for example, record waypoints or tracklogs of 2 or more gps, side by side, and check the discrepancies and relative accuracy among them. If the 3790 exit outside the standard certainly will prove to, once again, that the problem of relative precision is real (off road mode, look on road off ..)