Time Transfer Experiments with Indian Experimental Satellite “Apple”

Abstract

The availability of Indian Experimental Satellite “APPLE” gave an opportunity to try out various techniques and to firm up the specifications of the hardware and software required to be developed for precise time transfer, especially in relevance to a time dissemination service via Indian Operational Satellite INSAT-1. Some of the time transfer techniques were earlier experimented with French-German Satellite “Symphonie”. Time dissemination techniques such as TV, both passive and active and transmission of time code likely to be used with satellite INSAT-1B were tried out on APPLE on an experimental basis. The techniques of transmitting one pulse per second (1 PPS) to the satellite was used to range the satellite and it was compared with the conventional tone range technique. A simple, satellite orbit determination programme using the range data was developed and tested. This paper gives the results of the experiments carried out via “APPLE”.