Each millisecond pulsar is a natural, ultra-stable clock. The detector folds every incoming X-ray photon's arrival time modulo the pulsar's known intrinsic period into a histogram โ noisy at first, but its peak sharpens as more photons accumulate (uncertainty shrinks roughly as 1/โN). That peak's phase, compared with the phase expected at a fixed reference point, gives the extra (or shorter) light-travel time to the craft's true position along that pulsar's line of sight.
delay_i = -(P ยท dir_i) / c
P ยท dir_i = -c ยท delay_i for i = 1..3 pulsars
โ solve the 3ร3 linear system for P
- Free explore โ drag the X/Y/Z sliders to move the craft's true position; the detector keeps timing photons from all three pulsars and the triangulated fix converges as counts build up. Reset accumulation to start a fresh observation.
- Mission cruise โ dead reckoning only integrates the planned trajectory and never learns about unmodeled drift, so its error grows without bound. Pulsar navigation keeps folding photons throughout the whole cruise and re-solves the position periodically, so its error shrinks and stays tightly bounded โ a natural, infrastructure-free "GPS" that works anywhere in the solar system or beyond, with no radio uplink and no Earth-based tracking network.
- Detector sensitivity โ scales the simulated photon count rate; a bigger detector (or brighter pulsars) collects statistics โ and a precise fix โ faster.