Assessment of Differential Carrier Phase Measurements from Orbcomm LEO Satellite Signals for Opportunistic Navigation

摘要

A framework for positioning with carrier phase differential (CD) - low Earth orbit (LEO) (CD-LEO) measurements is developed. This framework utilizes a base and a rover and enables navigation with the Orbcomm LEO constellation without requiring prior knowledge of the rover’s position. The effect of ionospheric and tropospheric delays on the carrier phase and CD-LEO measurements are discussed. The residual ionospheric and tropospheric delays are studied as a function of the baseline. Moreover, the position dilution of precision (PDOP) is studied for the Orbcomm constellation, and it is found that a less than unity PDOP may be achieved for 8-minute wait times. Experimental results show a receiver positioning itself exclusively with CD-LEO measurements from two Orbcomm satellites with a position error of 11.93 m.