US 5,698,842 A · Sun sensor for orbiting spacecraft

Abstract

A sun sensor for use in orbiting satellites provides accurate attitude control yet eliminates the use of complicated optical components. The improved accuracy results from adjustment of the relative positions of a slit or pinhole aperture and a cooperating linear array of photodetector elements to increase the operating range of the sun sensor. Enhanced accuracy is further achieved by the use of a relatively wide slit instead of complicated optical components, in conjunction with a processing procedure which uses the finite angular subtense of the sun to increase the accuracy of the attitude control of the satellite by the sun sensor. A further embodiment of the invention includes a sun sensor device having dual "pinhole" apertures which is particularly useful for attitude control of a spinning satellite.

Claims16

Dependent claims

A sun sensor for orbiting spacecraft, said sun sensor comprising:

an array of photodetectors,
an element defining an opening therein for directing irradiance of the sun onto said array of photodetectors,
said opening in said element and said array being separated by a predetermined distance substantially equivalent to 1/2 the length of the array divided by tangent .theta., where .theta. is substantially equivalent to the angular field of view of said sun sensor, and
means for processing signals including means for generating a signal proportional to said irradiance by sampling said array and producing a pulse train having an envelope, means for demodulating said pulse train envelope, means for passing said demodulated pulse train through a low pass filter, and means for applying a threshold signal to said pulse train after it passes through said low pass filter.

1 more element

Dependencies are inferred from the claim text.

Sun sensor for orbiting spacecraft

Life of this patent

Sun sensor for orbiting spacecraft

Life of this patent

Abstract

Claims16