Theoretical Limits of Star Sensor Accuracy

TL;DR

This paper investigates the fundamental physical limits on the accuracy of star sensors used in small spacecraft, considering factors like stellar distribution, sensor size, and exposure time, and provides estimates for our galaxy location.

Contribution

It establishes the theoretical limits of star sensor accuracy based on physical and astronomical constraints, a novel analysis for miniaturized spacecraft instruments.

Findings

A fundamental accuracy limit exists for star sensors.

The limit depends on stellar distribution, sensor size, and exposure time.

Estimated accuracy bounds are provided for our galactic location.

Abstract

To achieve mass, power, and cost reduction, there is a trend to reduce the volume of many instruments aboard spacecraft, especially for small spacecraft (cubesats or nanosats) with very limited mass, volume and power budgets. With the current trend of miniaturizing spacecraft instruments one could naturally ask if is there a physical limit to this process for star sensors. This paper shows that there is a fundamental limit on star sensor accuracy, which depends on stellar distribution, star sensor dimensions and exposure time. An estimate of such limit is given for our location in the galaxy.