I'm investigating an industrial application that has a requirement to calculate with precision the relative distance on the ground between two outdoor points in the following scenario:
The first point will vary in height from 10m to 150m off the ground
The second point will always be around 3m - 5m off the ground
The points will be separated by 0m to 3m on the ground plane
I'm only interested in the separation on the ground, not the vertical separation
The precision should be within 10cm and I don't care about the absolute position accuracy.
Both points could be slowly moving around any axis before stabilising.
Looking into options available, I'm thinking standard GPS should be able to give me this type of precision if I compute the relative differences in position, which should hopefully compensate for the absolute positioning errors that GPS normally has, so I can avoid the complexity / cost of DGPS system.
I'm unsure if the differences in vertical height between the 2 points will impact the precision, and I also assume I have to use the a quality GPS receiver of the same type for both positions (to remove any differences caused by the receiver).
If this won't work, do I have any other options for this use-case (eg. combining an IMU with the GPS data, DGPS)?