Estimation of Mars Orbiter Orbit Based on Mars Color Camera Images

Abstract

Mars Orbiter Mission (MOM) is ISRO’s first interplanetary mission. Orbit determination of the spacecraft is always challenging especially for interplanetary missions. It is more difficult when the supported ground stations and the observations are limited. Presently, MOM is being supported by only ISRO’s 32-m antenna for a limited duration. Spacecraft is always facing a lot of disturbances from the sun and various disturbances in Martian orbit. Limited observation data from the ground station resulted in uncertainties in MOM’s orbit. In this paper, efforts are made to tune the MOM’s orbit based on its captured image by its camera and the spacecraft attitude information from the telemetry. Starting from the available coarse orbit information, the orbit parameters were tuned such that the tuned orbit and attitude can produce an image which is exactly matching with the observed one. The paper explains the principle of tuning the parameters using suitable image processing techniques, the System Tool Kit (STK) and MATLAB software. The method described in this paper can be implemented to any interplanetary satellites for orbit tuning as it can be implemented in on-board computer itself. Using present coarse knowledge of orbit, accurate attitude from star sensor, the spacecraft can generate features of the expected reference image. The observed and reference image difference can be used to tune present orbit as done in this paper.