Star Tracker

摘要

A star tracker determines a location or orientation of an object, such as a space vehicle, by observing unpolarized light from one or more stars or other relatively bright navigational marks, without imaging optics, pixelated imaging sensors or associated pixel readout electronics. An angle of incidence of the light is determined by comparing signals from two or more differently polarized optical sensors. The star tracker may be fabricated on a thin substrate. Some embodiments have vertical profiles of essentially just their optical sensors. Some embodiments include micro-baffles to limit field of view of the optical sensors.

主权项

1. A method for determining a direction to a source of unpolarized electromagnetic radiation, the method comprising:
exposing a first sensor to the unpolarized electromagnetic radiation, the first sensor being primarily sensitive to electromagnetic radiation polarized along a first axis and configured to generate a first signal proportional to a magnitude of the unpolarized electromagnetic radiation detected by the first sensor; exposing a second sensor to the unpolarized electromagnetic radiation, the second sensor being primarily sensitive to electromagnetic radiation polarized along a second axis, different than the first axis, and configured to generate a second signal proportional to a magnitude of the unpolarized electromagnetic radiation detected by the second sensor; determining a ratio of the first signal to the second signal; and using the ratio to calculate an angle of incidence of the unpolarized electromagnetic radiation.