Test of pulsar navigation with POLAR on TG-2 space station
Abstract
Pulsar navigation, which utilizes pulsar observations to determine the position or orbit of a spacecraft, has raised interests of many countries. Several projects, such as NICER, have been proposed. POLAR on-board the TG-2 space station of China has worked for about half year and its main task is to measure the polarization of the gamma-ray bursts. POLAR can also detect the photons from pulsars due to its large effective area (about 200 cm<sup>2</sup>) and wide field of view (more than 2π Sr). In this work we report our first results testing pulsar navigation with POLAR observations. A new navigation algorithm has been used that combines the orbit dynamics and pulsar profile analysis. With 31-day-long observations of the Crab pulsar, the TG-2 orbit was determined successfully. The parameter values of the orbital elements are solved and the errors are estimated by bootstrap method. The errors with 99.7% confidence are: semi-major axis error of 7.0 m, eccentricity error of 0.00026, inclination error of 0.023° Right Ascension of the Ascending Node (RAAN) error of 0.17°, error for argument of perigee of 0.042° and mean anomaly error of 0.042°.
