TanDEM-X Mission: Long Term in Orbit Synchronisation Link Performance Analysis

Inhalt:
The German satellites TerraSAR-X and TanDEM-X are flying in a close orbit formation as a bistatic interferometer to generate a high precision Global Digital Elevation Model (DEM). DEM data is acquired in bistatic operation with one active satellite illuminating the swath and both satellites receiving the ground echoes. This mode requires synchronization between the independent oscillators on TerraSAR-X and TanDEM-X, which is achieved by a synchronisation link using horn antennas on both satellites for omnidirectional coverage. This paper describes the synchronisation system and compares and verifies the SNR predictions by evaluating in orbit SNR measurements in different satellite formations.