A satellite navigation system using multiple antennas for providing the position
of multiple fiduciary points on an object even when fewer than four satellites
are visible to some or all the antennas. Satellite signals from the multiple antennas
are fed into at least one receiver. The receiver or receivers utilize constraint
information, which is independent of the satellite signals. These external constraints
are used to augment the signals received from the satellites, to obtain the position
solution for each antenna. In a preferred embodiment, a common reference clock
is used to provide an external constraint. Examples of other external constraints
that can be used in the current invention are distance between the antennas, inertial
measurement of attitude, rotational or linear position sensors, etc.