Patent ID: 7693659
Filing Date: 2010-04-06
Classification: G01C,G01S

Abstract:
1. A method of obtaining an initial position solution in a satellite navigation system for an object using a plurality of antennas, the antennas connected to at least one receiver, the antennas having a common reference clock, the method comprising: a. providing the common reference clock for each antenna; b. receiving satellite signals at each antenna; c. the receiver determining the initial position solution for the antennas using an external constraint in addition to the common reference clock and the satellite signals received at the antennas, wherein the external constraint is independent of received satellite signals and incorporated into an observation matrix, the initial position solution being solved from the observation matrix, and the external constraint corresponding to a spatial relationship between the antennas, the antennas being connected by a mechanical linkage; and d. the initial position solution being obtained using signals from fewer than four satellites at some or all antennas; wherein determining the initial position further comprises: the position solution being obtained using signals from fewer than four satellites at some or all antennas.