An attitude determination system and method is provided that includes at least
two sensor sets. Each sensor set is configured to detect electromagnetic radiation,
such as light of a known frequency. Specifically, each sensor set is configured
to detect electromagnetic radiation from a one of a plurality of point sources,
where each of the plurality of point sources emits electromagnetic radiation of
a different frequency. Each sensor set includes at least three sensors, with each
of the three sensors having a different orientation. The three sensors in the sensor
set are used to determine a relative orientation of the vehicle with respect to
one of the point sources. The at least two sensor sets in the system determine
the relative orientation with respect to at least two point sources. By placing
the sensors on a vehicle and knowing the direction to the point sources in a reference
frame coordinate system, the orientation of the vehicle with respect to this reference
frame can be estimated.