X-Ray Pulsar Timing Navigation for Cislunar Spacecraft: Time-of-Arrival Error Budgets

This paper presents a computed design study of a civilian orbital-safety system based on time-of-arrival navigation using millisecond pulsars as celestial clocks. It is a computed study of a civilian orbital-safety system, with no targeting application and no weapon application. Status: SIMULATED, NOT MEASURED. Under the stated assumptions the sizing gives a toa uncertainty us best of 3.57, a position sigma best m of 1.07e+03, and a position sigma worst m of 7.49e+03. Further computed quantities include combined fix sigma m of 4.75e+03; integration s of 3,600; pulsars used of 4. The design is sized end to end from the stated assumptions in the deposited computation, so every headline number can be reproduced, challenged and revised. Where the approach performs poorly, that result is reported at the same size as the favourable results: the limitations section names the conditions under which this design should not be chosen. The contribution is a complete, auditable sizing for one operating principle, intended to be compared like-for-like with sizings built on other principles for the same task.