I have been doing a lot of experimenting with the concept of a moving base. I have built a number of BeagleBone Black and U-Blox LEA6T powered GPS units.
I set them up as following: The Base antenna is at the rear of the vehicle and the Rover antenna in the front of the vehicle, I then drive a set route that includes passing under obstructions such as bridges, toll gates, high voltage power lines and large overhead traffic signs.
A FIX Solution is obtained very quickly and is for the most of the journey retained, passing under the mentioned obstructions the solution is reduced to float as expected. A Single solution was only experienced once passing slower than 60km/h under a double highway. The transition from Float to Fix was in the region of 4 to 7 seconds while travelling at an average speed of around a 100 km/h.
The trips were logged as base and rover.
The problem that I am experiencing is that when I replay the route the solution degrades to Single