My guess is that it doesn't assume anything about your motion model. The real question you should ask is what's the frequency of the positioning solution. Your

My guess is that it doesn't assume anything about your motion model. The real question you should ask is what's the frequency of the positioning solution. Your generic GPS unit computes solutions at 1Hz, more sophisticated ones do it at 5Hz, surveyor quality units can do it at 10-20Hz depending on firmware, but I think they're pushing the limit and probably assume something about the motion model. Applanix and Novatel solutions that use inertial sensors definitely make pretty strong assumptions of the motion model (see Kalman filter). OmniSTAR in particular and DGPS in general will operate under assumption that errors due to ionospheric and tropospheric effects change slowly in time and space. If this assumption is correct, then dynamics of the vehicle won't affect the corrections themselves. My point with all this is that 99% of the corrected GPS solution should theoretically be within x cm of some point on the true path of the vehicle no matter how it moves in a plane. The question is, if you're interested in real-time solution, how far will the vehicle be from that point by the time you get this fix, and if you're interested in capturing vehicle's travel, how well will the curve fit through these points match the true vehicle path.