TanDEM-X


TSX/TanDEM-X is a high-resolution interferometric SAR mission of DLR (German Aerospace Center), together with the partners EADS Astrium GmbH and Infoterra GmbH in a PPP (Public Private Partnership) consortium.

The mission concept is based on a second TerraSAR-X (TSX) radar satellite flying in close formation to achieve the desired interferometric baselines in a highly reconfigurable constellation. The primary goal of the innovative TanDEM-X/TerraSAR-X constellation is the generation of a global, consistent, timely and high-precision DEM.

Further important mission goals are:

  • New applications based on velocity measurements (ocean currents, glacier movements, road traffic etc.) with along-track interferometry (ATI)
  • Stimulation of innovative SAR techniques in bi-static measurement configuration (digital beamforming, super resolution, polarimetric SAR interferometry)
  • Development of close formation flying technology being a basis for many future missions
  • Development of precise orbit and baseline determination techniques using dual-frequency GPS (provided with the TOR instrument)
  • achievement of a long term availability of X-band data for scientific and commercial users, ensuring a sustainable product development and data delivery

 

In addition, TanDEM-X will provide the same capabilities as TerraSAR-X, i.e. Stripmap mode with 30 km swath and 3 m resolution, ScanSAR mode with 100 km swath and 16 m resolution and Spotlight mode with 10 km swath and up to 1 meter resolution.

 For more information: https://www.dlr.de/hr/en/desktopdefault.aspx/tabid-2317/

Further important mission goals are:
new applications based on velocity measurements (ocean currents, glacier movements, road traffic etc.) with along-track interferometry (ATI)
stimulation of innovative SAR techniques in bi-static measurement configuration (digital beamforming, super resolution, polarimetric SAR interferometry)
development of close formation flying technology being a basis for many future missions
development of precise orbit and baseline determination techniques using dual-frequency GPS (provided with the TOR instrument)
achievement of a long term availability of X-band data for scientific and commercial users, ensuring a sustainable product development and data delivery
In addition, TanDEM-X will provide the same capabilities as TerraSAR-X, i.e. Stripmap mode with 30 km swath and 3 m resolution, ScanSAR mode with 100 km swath and 16 m resolution and Spotlight mode with 10 km swath and up to 1 meter resolution.

TANDEM-X TECHNICAL SPECIFICATIONS:

Spacecraft

Rebuild of the TerraSAR-X satellite which was based on the Astrium Flexbus concept and extensive heritage from the CHAMP and GRACE missions

Features

- X-band downlink horn antenna is mounted at the tip of a 3.3 m long boom
- SSMM (Solid State Mass Memory) data storage with a capacity of 768 Gbit (EOL)
- High-pressure nitrogen gas propulsion system for formation flying

Spacecraft launch mass

1340 kg (spacecraft: 1220 kg, fuel: 120 kg)

Spacecraft size

5 m length, 2.4 m diameter (hexagonal cross section)

Spacecraft design life

5 years nominal (after the end of the commissioning phase)

RF communications

- X-band of 300 Mbit/s link of payload data downlink with DQPSK modulation;
- S-band uplink of 4 kbit/s (2025-2110 MHz), BPSK modulation; S-band downlink of 32 kbit/s to 1 Mbit/s (2200-2400 MHz), BPSK modulation

Primary payload

Secondary payloads

- TDX-SAR instrument is identical to the TSX-SAR (TerraSAR-X SAR instrument)
in layout, operational performance and support modes.
- TOR (Tracking, Occultation and Ranging)
- LCT (Laser Communication Terminal)
- LRR (Laser Retroreflector)