StarNAV optical sensor system

A method for determining a spacecraft instantaneous velocity using starlight, the method comprising:

• determining, by a star pairing module, a plurality of star pairs in a selected star field image, the selected star field image comprising a plurality of star images;
• estimating, by a line of sight estimation module, an apparent bearing direction to each star in at least some of the plurality of star pairs;
• determining, by the line of sight estimation module, a respective apparent inter-star angle corresponding to one of the apparent bearing directions for each star pair of the least some star pairs, and determining a stellar aberration based on a change in the apparent inter-star angle of at least one of the plurality of star pairs;
• and
• estimating, by a velocity estimation module, a spacecraft velocity to within a total velocity error based, at least in part, on the apparent inter-star angles and the stellar aberration.