Design and Analysis of North-seeking Method by Time Differencing Method of Gyro-theodolite

With the development of electronic technology, and rapid improvement of accuracy for electronic timing, north seeking of gyro-theodolite emerges lots of new methods. As one of the most common methods of measurement for precise north seeking by mechanical gyroscope, time differencing method is a way of getting north of gyroscope, which mainly calculates the span time for two scale marks symmetrical for zero scale mark passing through gyro-theodolite sensitive part. The paper introduces north-seeking theory of time differencing method, and puts forward a north-seeking solving method by time differencing method. Without necessity of changing instrument structure, this method only needs to be re-implanted solving program, and then the true north azimuth can be solved. The result of experiment shows that this method can not only guarantee the measurement accuracy of north seeking, but also can effectively simplify traditional time differencing methods of measurement and solution, and it can reach the propose of quickly seeking north.