DEM products from TerraSAR-X & TanDEM-X. Nora Meyer zu Erpen //

Transcription

1 DEM products from TerraSAR- & TanDEM- Nora Meyer zu Erpen //

2 GEO-Information Services within Astrium and EADS Airbus Eurocopter Cassidian Astrium Turnover 2009: 4.8 billion Staff 2009: 15,000* Astrium Satellites Astrium Services Space Transportation Telecommunications Secure Satcom Systems GEO-Information Navigation * France, Germany, UK, Spain, Netherlands Date - 2

3 GEO-Information Services: Key Facts & Figures Staff: +900, located in 12 countries Combining the talent and capabilities of Spot Image and Infoterra teams, integrated within the GEO-Information division of Astrium Services An international network of partners & customers Spot Image Corporation Infoterra UK Infoterra Spain Spot Image Infoterra Germany Infoterra Hungary Spot Infoterra Hellas Beijing Spot Image Infoterra AP Tokyo Spot Image Spot Image Brasil Spot Asia Spot Imaging Services Date - 3

4 Key Assets & Skills Data management & data access EO data acquisition (spaceborne, airborne & field data) Consultancy, training & know-how transfer Data processing Covering the whole value-chain Geo-information services Date - 4

5 TerraSAR-Programm TerraSAR- Mission Successful launch Resolution up to 1m Geometric accuracy unrivalled by any other commercial spaceborne sensor today Weather and sun inclination independent data acquisition worldwide Unique agility (rapid switches between imaging modes and polarisation) Public Private Partnership (DLR, EADS Astrium) Date - 5

6 TerraSAR-Programm TanDEM- Mission TerraSAR- add-on for Digital Elevation Measurement (DEM) Twin Satellite Constellation: TerraSAR- & TanDEM- Launch satellite: TanDEM-Mission start (twin constellation): Primary Mission Goal: homogeneous, high-quality global DEM using interferometry Unprecedented accuracy, coverage & quality Consistent, seamless coverage of the Earth s land surface within ~ 3 years Public-Private Partnership (DLR / Astrium) Date - 6

7 TerraSAR Missions Public Private Partnership (PPP) Development of satellite operating system Development of the ground segment for data reception Data procession, archiving, calibration and distribution (non-commercial) Development & assembly of the satellite Satellite launch Development of a commercial service system Commercialization of the TerraSAR-/ TanDEM- data & products Date - 7

8 TerraSAR-: Technical data Mission Agency Launch Orbit height Inclination Satellite mass (start) Satellite size Energy consumption Operational life Radar frequency Resolution TerraSAR- DLR/ Astrium (D) (Baikonur, Kasachstan) 514km 97,44 degree (sun-synchronous orbit) Approx kg 5m height by 2,4m diameter 800 watt (Average) At least 5 years 9,65 GHz (Frequency band: -Band) SpotLight (HR): >= 1m (scene size: 5 to 10km x 5km) SpotLight: >= 2m (scene size: 10km x 10km) StripMap: 3 m (scene size: 30km x 50km) ScanSAR: 18m (scene size: 100km x 150km) Date - 8

9 Digital Elevation Information: Methods Radargrammetry (Stereo 3D reconstruction) SAR Interferometry (repeat pass InSAR: 11 days) (single pass InSAR: simultaneous) Date - 9 Utilization of two images with different acquisition geometry (intensity only) less accurate than InSAR 9 Utilization of the phase difference of two images with the same geometry more accurate, where feasible

10 Digital Elevation Information: Methods Mission Method Description Comments TerraSAR- Radargrammetry -Based on amplitude data -two acquisitions with different acquisition angles (steep & flat stereo pair) -RDG is robust to changes on earth surface -RDG is independent from atmospheric circumstances and changes -difference between acquisition dates < 11 days InSAR (repeat pass) -Based on phase information - two acquisitions from almost the same orbit position InSAR is sensitive to temporal decorrelation: a) surface reflection characteristics may change between the two acquisition dates b) strong sensitivity to atmospheric changes 11days minimum separation between acq. dates TanDEM- InSAR (single pass) -Based on phase information - two acquisitions from almost the same orbit position Advantage to repeat pass: Simultaneous data acq.: no temporal decorrelation (no changes in reflection characteristics, no atmospheric changes) very high vertical accuracy Date - 10

11 InSAR One area is covered: two times from almost parallel orbit positions Repeat pass: TerraSAR- (Single pass: TanDEM- Mission) Elevation information is derived from the difference distance from one ground point to each satellite position Date - 11

12 Radargrammetry One area is covered: two acquisitions with different acquisition angles (steep & flat stereo pair) ~ 20 disparity angle Date - 12

13 Radargrammetry ascending Data acquisition & DSM extraction: acquisition of at least one TS- stereopair images Reduce influence of layover & shadow effects: From both looking directions (ascending & descending) Merge of ascending & descending DSM (Mean value approach) 13 Date - 13 descending

14 TerraSAR-: Radargrammetry-DEM Products Date - 14

15 Digital Elevation Models (DEM) TerraSAR- Elevation DSM (Radargrammetry): Sensor: Independent of weather conditions Continuous representation of earth surface (no data gaps based on clouds) Frequency band: -Band (9,5 GHz) DSM (Digital Surface Model): All objects (trees, houses etc.) are included in this model. It represents the surface as we observe it from above (e.g. from an airplane). DSM Digital Surface Model DTM Digital Terrain Model Date - 15

16 TerraSAR- Elevation DEM products Product variant overview: Product DEM level 0 (raw-dsm) DEM level 1 (TerraSAR- Elevation DSM basic) DEM level 2 (TerraSAR- Elevation DSM) DEM level 3 (TerraSAR- Elevation DTM) Editing Description Digital Surface Model (raw-dsm as output from the radargrammetry processor) Digital Surface Model, basic version Artefact removal Digital Surface Model, hydro enforced version (based on DEM level1) Implementation of specified hydro network, airstrips Digital Terrain Model (based on DEM level 2) Processing DSM data to bare earth Not operational yet (expected product release 03/2011) Date

17 TerraSAR- Elevation DEM products Auxiliary Layer of TS- Stereo DEM: Product / Package DEM_1 DEM_2 DEM_3 Format Source mask ESRI shape Shadow & Layover mask ESRI shape Void mask 1-bit GeoTIFF Height Error mask 8-bit GeoTIFF Interpolation mask 1-bit GeoTIFF Filling mask 4-bit GeoTIFF Water body mask 1-bit GeoTIFF Editing mask 1-bit GeoTIFF Contour lines ESRI shape Output from radargrammetry processor Results from DEM editing Date

18 Date - 18 TerraSAR- Elevation DEM products

19 Validation & Verification Approach DEM QA process Qua Qualitative approach: visual / descriptive Shaded relief: Bogor shaded Relief Profil plot: TS-Stereo DSM Height [m] ICESat Points SRTM Radargrammetry DSM Zinfo Quantitative approach: statistic absolute vertical error (expressed in RMSE / LE90) Date

20 TerraSAR- Elevation DSM Product specification: Method Grid Spacing Absolute vertical accuracy Relative vertical accuracy Horizontal accuracy Area of interest Data Format Vertical Unit Projection Information Auxiliary Metadata Radargrammetry based on TerraSAR- StripMap stereo pairs 10 m 5-10 m (90% linear error) depending on terrain 5-10 m (point to point within 100 x 100 km, 90% linear error) 5-10 m (90% circular error) depending on terrain A minimum of 500 km² per order 32-bit GeoTiff Meter UTM projection; UPS projection for polar regions. Horizontal ref. datum WGS84, Vertical ref. datum EGM96 Metadata in ML-Format (ISO compliant Next release) Date - 20

21 Components of metadata ISO xml Metadata html stylesheet Date - 21

22 Verification & Validation Sites DSM verification & validation Evaluation based on a variety of test areas and reference data Test sites: Alpine / Ice Snow: Juneau (USA) Dry area: Ft. Irvin (USA) Tropical Forest: Montserrat Alpine/Ice/Snow: Wallis (CH) Mountainous-Flat: Eifel (DE) Mediterranean: Marseille (FR) Flat: El Manteco (VEN) Mountainous: Black Forest & Aulendorf (DE) Mountainous: Solothurn (CH) Desert: Oman Tropical Forest: Sabang (IND) Mountainous: Yutan Tropical Forest: Malaysia Tropical Forest: Kalimantan (IND) Urban: Johannesburg (ZA) Reference: high quality DEM (LIDAR, aerial photographs) Reference: GPS point samples Date

23 Date - 23 TanDEM-: Digital Elevation Models

24 Global DEM: Data Acquisition Plan 5 months 1 year 1 year 6 months 3 months Commissioning Phase 1 global DEM acquisition with small baselines 1 global DEM acquisition with larger baselines DEM data takes for difficult terrain with different viewing geometry Customized DEMs with large interferometric baselines Production TD_IDEM TD_DEM DEM Availability TD_IDEM TD_DEM Nominal Data Acquisition 3 (+?) Years Date - 24

25 Global DEM: Product overview TanDEM- intermediate DEM Only one coverage available Errors and voids expected in mountainous regions Available also with reduced pixel spacing (factor 2 & 4) TanDEM- DEM - Final DEM Product of the TanDEM- Mission Two complete coverages of the earth plus additional acquisitions for difficult terrain Accuracy according to HRTI-3 Available also with reduced pixel spacing (factor 2 & 4) DEMs on special user-request Accuracy according to HRTI-4, only for local size regions Date - 25

26 Global DEM: Specification Standards for Digital Absolute Elevation Vertical Spatial Resolution Models (DEM) DEMs Accuracy(90%) Relative Vertical Accuracy (point-to-point in 1 cell, 90%) DTED-1 90 m x 90 m < 30 m < 20 m DTED-2 30 m x 30 m < 18 m < 12 m HRTI-3 HRTI-4 12 m x 12 m < 10 m < 2 m 6 m x 6 m < 5 m < 0.8 m SRTM / -SAR Date - 26

27 TanDEM- DEM data Mount Aetna, Italy Date - 27

28 TanDEM- DEM data Salar de Uyuni, Bolivia Date - 28

29 TerraSAR-2 next step in service continuity Service continuity, sustainability TanDEM- as a bridge constellation enabled New commercial business model Public Private Partnership TerraSAR- / TanDEM- Commercial mission TerraSAR-2 TerrSAR-2 mission specifics Market driven (service definition) Service Subscription, Partnerships Coordinated sharing of excess collect capacities TS1 PPP TD PPP PAZ Hisdesat TS2 Infoterra TerraSAR-2 will provide service continuity in the family of sustainable, reliable series of high quality SAR satellites TS3 PPP Date - 29

30 Vielen Dank für Ihre Aufmerksamkeit Nora Meyer zu Erpen Astrium Services Geo-Information - Infoterra GmbH Platz der Einheit Potsdam T: / F: nora.meyer.zu.erpen@astrium.eads.net Date - 30