A method and system obtains precise survey-grade position data of target
points in zones where precise GPS data cannot be obtained, due to natural
or man-made objects such as foliage and buildings. The system comprises a
GPS receiver mounted on a survey pole, with an inertial measurement unit
(IMU) and an electronic distance meter (EDM) also mounted on the pole.
The system and method obtains GPS data when outside the zone and uses the
IMU inside the zone to traverse to a target point, using the EDM to
obtain data reduce accumulated errors which occur with the IMU.