Methods for solving astronavigation problems using digital optical cameras

Two methods of determining navigation parameters using an astronavigation system with a star tracker, which is a digital camera with a wide field of view, are considered. The first method used in marine astronomy is a traditional difference-altitude-azimuth method for solving the navigation problem of observing a group of stars and the visible horizon. The second method, used in, is based on measuring the orientation of a star tracker in an inertial (equatorial) coordinate system and its relationship to geocentric and local geographic coordinate systems. It is noted that the use of a high-resolution digital camera as a star sensor for astroinertial navigation systems makes it possible to implement both methods for determining navigation parameters. It is emphasized that the nature of the errors in determining orientation by the two methods under consideration is different, so that their combined application increases the accuracy of solving the navigation problem. A scheme of an algorithm for the integrated application of orientation data relative to the horizon based on the readings of inertial sensors and a visible horizon sensor is presented. Results of digital simulation.