Concurrent Imaging for TerraSAR-X: Wide-Area Imaging paired with High-Resolution Capabilities

The concurrent imaging technique enables parallel acquisitions with different beams or modes, e.g., a wide area Stripmap mode with a high resolution Spotlight mode. Such a concurrent Stripmap/Spotlight imaging technique is investigated for TerraSAR-X. This technique employs a pulse-topulse interleaving scheme to acquire two acquisitions - even of disjunctive areas - at the same time, offering products with different resolution and coverage portfolios. This capability is especially interesting for customers interested in an overview of a larger area but at the same time observing an area of interest with higher resolution, e.g., for infrastructure monitoring or reconnaissance applications. The basic concept, as well as the driving system parameters, are discussed in detail, together with a coverage analysis revealing the high availability rate of the mode combinations on a global scale. A processing approach reusing a substantial part of the existing infrastructure is described and exemplary acquisitions are shown, together with a detailed performance analysis with respect to resolution and ambiguities

TerraSAR-X Ultra Stable Oscillator Temperature Drift Compensation

After 15 years of successful radar operations in space, the German SAR satellite TerraSAR-X (TSX) showed peculiarities in the frequency of the Ultra Stable Oscillator (USO) since 1st of Nov. 2022 13:56 UTC. In conclusion, we will show at the workshop how we can maintain the excellent performance of TSX despite the new challenges the ageing instrument poses

Evaluation of coarse- and fine-pointing methods for optical free space communication

Free space optical communication provides a way to increase the data rate that is limited by the capabilities of current radio links. While also allowing saving of on-board power and shrinking of the size of the communication terminals, it presents more challenges in terms of the need of extremely precise pointing between the two partners involved in the link. Successful laser communication tests have been performed, e.g. between two satellites in space and between a satellite and a ground based fixed partner. A link through the atmosphere involving airborne moving terminals experiences disturbances like base-motion vibrations, fast relative motion and disturbances within the medium of propagation. These increase the requirements towards the pointing systems of the communication terminals. The traditional way to cope with misalignment is to operate two subsystems in parallel – a coarse pointing and a fine pointing one. The current work researches on the possible technologies for the so-called fine pointing assemblies. It proposes the introduction of a medium pointing assembly as the stage between the coarse and fine pointing ones. A general design of the new approach is also presented and analyzed. Furthermore, a laboratory experiment was set up and the results of it were discussed according to the expected ones.Validerat; 20101217 (root

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

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

Ordering and Planning of DEM-On-Demand in IOCS

The technical note in hand gives an overview of the necessary workflow implementations and system specifications in order to introduce DEM-on-Demand handling in the IOCS. The most important functions that need an update are the order acquisition and the TanDEM-X acquisition generation and planning

Customization Proposal of DLR Tools

This document describes the proposal for the customization of the DLR tools delivered to INTA for the PAZ Ground Segment