Martin Spott wrote: > Does anyone have experiences with portable GPS recievers ? Do they > tend to increase the precision of their coordinate output if you > remain at a location for several minutes ?
My wife have gotten into geocachine (www.geocaching.com) over the last two years, so we've played with these things quite a bit. Yes, almost all consumer devices will do averaging, although none of them tell you the algorithm they use. Given enough time, they will converge down to a value that is accurate to within the accuracy of the system (a few meters). I doubt a few minutes would be enough, I would give it several hours to ensure that a large number of satellites triplets get used in the solution. Averaging over a few minutes is only going to reduce sampling error, it probably won't be switching between its satellite signals, so systematic error of one satellites signal (due to ionosphere refraction, etc...) won't be caught. Honestly, there's a lot of voodoo in consumer GPS hardware. Sometimes the sky looks great, you see really strong signal from 8 satellites, and still get a fix that is off by 40m or more and need to reboot the unit to get it to see straight. Andy _______________________________________________ Flightgear-devel mailing list [email protected] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
