# Pulsar Timing and its Application for Navigation and Gravitational Wave Detection

## TL;DR

Pulsars serve as natural cosmic clocks enabling applications like autonomous space navigation and low-frequency gravitational wave detection through precise timing measurements.

## Contribution

This paper discusses the potential of pulsar timing for autonomous navigation and gravitational wave detection, highlighting recent experiments and future prospects.

## Key findings

- Pulsars can be used as natural navigation beacons for spacecraft.
- Pulsar timing can detect low-frequency gravitational waves.
- Current experiments are advancing galactic-scale gravitational wave detection.

## Abstract

Pulsars are natural cosmic clocks. On long timescales they rival the precision of terrestrial atomic clocks. Using a technique called pulsar timing, the exact measurement of pulse arrival times allows a number of applications, ranging from testing theories of gravity to detecting gravitational waves. Also an external reference system suitable for autonomous space navigation can be defined by pulsars, using them as natural navigation beacons, not unlike the use of GPS satellites for navigation on Earth. By comparing pulse arrival times measured on-board a spacecraft with predicted pulse arrivals at a reference location (e.g. the solar system barycenter), the spacecraft position can be determined autonomously and with high accuracy everywhere in the solar system and beyond. We describe the unique properties of pulsars that suggest that such a navigation system will certainly have its application in future astronautics. We also describe the on-going experiments to use the clock-like nature of pulsars to "construct" a galactic-sized gravitational wave detector for low-frequency (f_GW ~1E-9 - 1E-7 Hz) gravitational waves. We present the current status and provide an outlook for the future.