Comment on Increasing Local GPS Accuracy for a Small Robot by yet another bruce

In reply to Observer.

This is a good idea and is very similar to Differential GPS. You don't even need your own fixed receiver, DGPS data is available from a number of commercial and Government organizations. Standard DGPS (Differential GPS) yields 0.3 to 1.0 meter accuracy. RTK typically gives you 1-2 cm accuracy.

As I understand it the big difference between kinematic GPS and various flavors of regular GPS is that kinematic GPS uses the phase of the GPS carrier (L1 carrier wavelength 19cm for example) while regular GPS correlates the pseudorandom chips at a bandwidth of 2 MHz (wavelength 150m).

The challenge of kinematic GPS is that the phase repeats every 19cm so you have to know your position to within 10cm to avoid ambiguity. Once you lock on you can continue to track your position unambiguously hence the name kinematic.