TanDEM-X Mission Status & Commissioning Phase Overview

Transcription

1 TanDEM-X Mission Status & Commissioning Phase Overview M. Zink TanDEM-X Ground Segment Manager 17-February-2011 TanDEM-X Science Team Meeting 17-Feb OP

2 TerraSAR-X-Add-on for Digital Elevation Measurements Page 2

3 Add-ons for TanDEM-X (1/2) Second Satellite (close copy, only minor modifications) Measures for save formation flight (inter satellite link, exclusion zones, new magnet torquer safe mode, sync warning) Satellite operations in close formation (more frequent S-Band contacts for monitoring, novel sub-systems for orbit and formation monitoring & control) Advanced power/thermal model allows for operational profiles beyond design specification limits (in average 210s active/130s passive per orbit) Dedicated TanDEM-X Acquisition Planner considering height performance and system resources Page 3

4 Add-ons for TanDEM-X (2/2) New joint TerraSAR-X/TanDEM-X Mission Planning for combination of the global DEM acquisitions with individual TerraSAR-X data takes Bi-static operation & synchronisation Precise baseline determination Globally distributed ground station network (raw data volume 350 TByte) Dedicated processing chains and work flows for DEM generation, calibration and mosaicking (overall data volume 1500 TByte) Comprehensive integration and test program performed well prepared for commissioning phase Page 4

5 Slide 5

6 Madagascar :55:44 (DT 11)

7 TanDEM-X Commissioning Phase June 10 July 10 Aug 10 Sep 10 Oct 10 Nov 10 Dec 10 Launch 21 June TDX Orbit Drift km 20 km 20 km Formation Early Orbit Phase First SAR Image 24 June (MET +3.6) 6 Month Commissioning Phase Grg Segment Checkout First DEM 16 July (MET +25) TDX Monostatic Comm. Phase First bi-static SAR image 8 August (MET +48) Page 7

8 Tien Shan, China T12:39:09

9 Drygalski Glacier, Antarctica T23:40:49

10 Geometric and Radiometric Cross Check TSX vs. TDX TSX-1 Delta Range [m] 1,5 1,25 1 0,75 0,5 0,25 0-0,25-0,5-0, ,25 TSX Geometric Calibration 2010 Geometric Offset in Range 10,01 = nsec / cm = 1.90 nsec / cm s003 s009 s005 s012 Asc Des Offset s016 s023 s026 s019 8,34 6,68 5,00 3,34 1,67 0,00-1,67-3,34-5,00-6,68-8,34-1,5-10, Look Angle [deg] Delta Instrument Delay [ nsec] Geometric Cross Offset TSX TDX TSX-1 TDX-1 = - 80 psec rg TSX-1 TDX-1 = cm ~ 1/3 Wavelength! Delta Range [m] TDX-1 1,5 1,25 1 0,75 0,5 0,25 0-0,25-0,5-0, ,25 s003 TDX Geometric Calibration Annotated Instrument Delay [ nsec ] Geometric Offset in Range 10,01 Asc 8,34 Des 6,68 Offset 5,00 3,34 1,67 0,00 s009 s016 s023-1,67 s005-3,34 s012 s019 s026-5,00-6,68-8,34 = nsec / cm = 2.03 nsec / cm -1,5-10, Look Angle [deg] Radiometric Cross Offset TSX TDX cross ~ db Delta Instrument Delay [ nsec] [db] grass TDX urban TDX grass TSX urban TSX mean TDX mean TSX TDX = db Grass TDX = db = db Grass TSX = db = db 0 of Distributed Targets X X Grass Area X X Urban Urban TDX = db = db Urban TSX = db = db TSX = db Page 10

11 Comparison TDX versus TSX TSX TDX Internal Calibration Instrument Drift (Ampl./Phase) 0.15dB / 0.5 deg 0.1dB / 0.85 deg TRM-Charact. (Ampl./Phase) < 0.2 db / < 2 deg < 0.2 db / < 2 deg Geometric Calibration Pixel Localisation Accuracy (az/rg) 48.3 cm / 28.5 cm 49.9 cm / 30.4 cm Antenna Pointing Azimuth / Elevation 1 mdeg / 4 mdeg < 2 mdeg / < 2 mdeg Antenna Model Shape and Gain-Offset ±0.2 db ±0.2 db Radiometric Calibration Radiometric Stability 0.15 db / (2 years) 0.15 db / (2 years) Rel. Rad. Accuracy (Strip/Scan) 0.16 db / 0.27 db 0.2 db / 0.3 db Abs. Rad. Accuracy (Strip/Scan) 0.34 db / 0.40 db 0.48 db / 0.52 db Page 11

12 Comparison TDX versus TSX TSX TDX Internal Calibration Instrument Drift (Ampl./Phase) 0.15dB / 0.5 deg 0.1dB / 0.85 deg TRM-Charact. (Ampl./Phase) < 0.2 db / < 2 deg < 0.2 db / < 2 deg Perfect Twins Geometric Calibration Pixel Localisation Accuracy (az/rg) 48.3 cm / 28.5 cm 49.9 cm / 30.4 cm Antenna Pointing Azimuth / Elevation 1 mdeg / 4 mdeg < 2 mdeg / < 2 mdeg Antenna Model TSX TDX Shape and Gain-Offset ±0.2 db ±0.2 db Radiometric Calibration Radiometric Stability 0.15 db / (2 years) 0.15 db / (2 years) Rel. Rad. Accuracy (Strip/Scan) 0.16 db / 0.27 db 0.2 db / 0.3 db Abs. Rad. Accuracy (Strip/Scan) 0.34 db / 0.40 db 0.48 db / 0.52 db Page 12

13 14 October 2010: Close Formation Flight Slide 13

14 TanDEM-X Commissioning Phase June 10 July 10 Aug 10 Sep 10 Oct 10 Nov 10 Dec 10 Launch 21 June TDX Orbit Drift km 20 km 20 km Formation Close Helix-Formation m Early Orbit Phase First SAR Image 24 June (MET +3.6) 6 Months Commissioning Phase Grg Segment Checkout First DEM 16 July (MET +25) TDX Monostatic Comm. Phase First bi-static SAR image 8 August (MET +48) Bi-static Commissioning Phase First close formation DEM 19 October (MET +124) Slide 14

15 Mt. Etna

16 Exclusion Zones HELIX HELIX TDX TSX-1 TSX may not transmit in asc. orbit TSX DEM exclusion zones (example) 30 0 TDX-1 DEM TSX-1 TDX-1 possible beams & side-lobes standard TSX beams + PN-Gating beams TDX may not transmit in desc. orbit For each satellite and looking mode, an Exclusion Zone is defined Exclusion Zone: argument of latitude region, where SAR transmissions have to be suppressed Slide 16

17 Bi-static Operation - Synchronisation Bi-static operation of TSX and TDX requires synchronisation of independent oscillators Phase referencing by exchange of pulses via synchronization link Leap PRIs compensate drift of Echo Window Sync Warning for mutual health check Slide 17

18 TanDEM-X Commissioning Phase June 10 July 10 Aug 10 Sep 10 Oct 10 Nov 10 Dec 10 Launch 21 June TDX Orbit Drift km 20 km 20 km Formation Close Helix-Formation m Early Orbit Phase First SAR Image 24 June (MET +3.6) 6 Months Commissioning Phase Grg Segment Checkout First DEM 16 July (MET +25) TDX Monostatic Comm. Phase First bi-static SAR image 8 August (MET +48) Bi-static Commissioning Phase First close formation DEM 19 October (MET +124) DEM Acquisition Slide 18

19 1 st (available) operational DEM Acquisition from Dec 12th ( Northern Greenland, HoA 53m ) Slide 19

20 TanDEM-X Mission Status Commissioning phase finished according to plan (more than 8000 DTs) Goal to start global DEM acquisition achieved Performance and calibration of the individual satellites within specification or better perfect twins Stable operations in close formation TSX & TDX and the combined TerraSAR-X/TanDEM-X Ground Segment are performing remarkably well Calibration of the bi-static synchronisation system ongoing Slide 20