抄録
Recently the activities for the development of micro- and nano- satellites like a cubesat are being increased. A lot of satellites are operated at a ground station located in a university, but public orbit information is used. In this paper, the orbit determination system is constructed using observations of Doppler frequency at a low-cost ground station. The traditional batch state estimation filter is used, and the orbital elements of satellite position and velocity in inertia coordinates are determined from the Doppler frequency of receiving signals. The verification tests are conducted using UHF-band signals (about 430 MHz) received at an amateur radio station and S-band signals (about 2.2 GHz) received at a 2.4-m parabola antenna from real satellites, and the valid performance is conformed for tracking satellites not depending on public orbit information. The error is max. 0.3 degrees in direction and max. 3.9 km in position for UHF-band signals, and max. 1.1 degrees in direction and max. 37 km in position for S-band signals. This method is valid especially for low-earth-orbit satellites with large Doppler effect.
