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This paper initially reviews types of deep space navigation methods. Then, it studies the use of pulsars as one of sources emitting electromagnetic waves in navigation; hence more details regarding the pulsar physics and the history of navigation using pulsars are presented. The various methods of navigation (including radio method), their advantages and disadvantages-in comparison with navigation using pulsars in spacecraft-are discussed. Then, the equations necessary for calculating position and velocity of a spacecraft (such as the arrival time of pulse from pulsar to the receiver) are introduced, and the methods of calculating position and velocity are dealt with. Finally, two algorithms are presented for positioning, and one for velocity. Attitude determination follows the same simple methods presented in various articles.

There are different attitude determination methods which have been used in satellite and spacecraft by star tracker. Each of these methods have its own advantages and disadvantages depending on their application, stochastic characteristic of noise on sensors (bias or noise), and weight of noise falling on different sensors. The present study has thus explored the major methods from two perspectives: the effect of input noise or bias on each star sensor and the corresponding weight of each noise or bias falling on each sensor. These aspects are compared in each method and the optimal method according to each condition is introduced. N Vector, Triad, Quest, Q method and least square method are the methods studied and simulated in this article. Finally, a comparison is made between the methods and the optimal method is introduced theoretically and practically.

This paper reports on the results of attempts to reduce the positioning error of strap down inertial navigation system using attitude information obtained by star tracker. In this regard, the position error equations of different channel in inertial navigation are modeled and error share of each sensor in position and attitude determination drifts are investigated. In continue celestial navigation and the use of star tracker in attitude determination and positioning on different frames are considered. Then, new equations of inertial navigation aided by attitude determined with star tracker are introduced. Through the use of the new equations, attitude and position in navigation and inertial frame are recalculated and compared with the parameters obtained by inertial navigation. The results suggest a considerable reduction in position error, particularly in the height channel.