Originally posted by B1Driver
Im sure that owners of competition ready sailplanes can afford a better GPS unit than the el cheapo ones at walmart. (not 100% sure but, since the airlines have challenged the government for the decoders of A band, I believe they have been released...hence the GPS approachs, ect..ect. Therefore, if you can afford it, you can get extremly accurate readings from GPS units. All in all..you get what you paid for...want to impress your friends..go to walmart...want to impress nonbelievers, go to NASA.
Sailplane, aeronautics GPS are not more precise than "Walmart" GPS, they have more features, measure from more satellites, the usual big difference being they take into account altitude....duh....
Those specifics for Sailplane are also arrivals calculators, which make them very specialised, hence very costly. Still has nothing to do with distance (and speed) measurement accuracy.
Bernard