1 / 26

Alos optical data processing

Alos optical data processing. End of Stage Presentation. Trainee: ARNAL Etienne etienne.arnal@isen.fr Tutor: Mr COLIN Olivier olivier.colin@esa.int. Presentation Outline. Alos Product Descriptor (PRISM and AVNIR2) Alos Image Processing (PRISM and AVNIR2) Digital Elevation Model

jade-french
Download Presentation

Alos optical data processing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Alos optical data processing End of Stage Presentation Trainee: ARNAL Etienne etienne.arnal@isen.fr Tutor: Mr COLIN Olivier olivier.colin@esa.int

  2. Presentation Outline • Alos Product Descriptor (PRISM and AVNIR2) • Alos Image Processing (PRISM and AVNIR2) • Digital Elevation Model • 3D results ESRIN - ARNAL Etienne

  3. Data Image DEM 3D results Alos Product Descriptor (1/5) • Realisation of a cqfd dictionary containing the fields of the Product Format Description of Prism and Avnir2. • Allows to find quickly all fields of level: 1A = raw data extracted from the Level 0, 1B1 = with radiometric corrections, 1B2R = geo-referenced, 1B2G = geo-coded. ESRIN - ARNAL Etienne

  4. Data Image DEM 3D results Alos Product Descriptor (2/5) • CQFD: binary data reader. FILE ; |_ VOL ; | |_ VolumeDescriptor ; | |_ FilePointer ; (3 to 9) | |_TextRecord ; |_ LED ; | |_ CommonFileDescriptor ; | |_ FileDescriptor ; | |_ SceneHeader ; | |_ Ancillary1 ; | |_ Ancillary2 ; | |_ Ancillary3 ; in the data ESRIN - ARNAL Etienne

  5. Data Image DEM 3D results Alos Product Descriptor (3/5) • CQFD: binary data reader. |_ IMG ; | |_ IMG1 ; (1 to 6) | | |_ CommonFileDescriptor ; | | |_ FileDescriptor ; | | |_ Line 1 ; | | |_ … | | |_ Line n ; |_ TRL ; | |_ CommonFileDescriptor ; | |_ FileDescriptor ; | |_ Trailer ; |_ SUP ; | |_ CommonFileDescriptor ; | |_ FileDescriptor ; | |_ Ancillary ; in the data ESRIN - ARNAL Etienne

  6. Data Image DEM 3D results Alos Product Descriptor (4/5) • CQFD: binary data reader. |_ TiePoints ; | |_ Line 1 ; | | |_ Lat ; | | |_ Long ; | |_ … | |_ Line n ; in the data (I,J) are pixel and line of corrected image (φ,λ) are degrees of latitude and longitude ESRIN - ARNAL Etienne

  7. Data Image DEM 3D results Alos Product Descriptor (5/5) • Thanks to this CQFD dictionary, everybody can find a precise field in every Prism and Avnir2 data. • The next step is to create image. ESRIN - ARNAL Etienne

  8. Data Image DEM 3D results Alos Image Processing (1/5) 3 various image data structure: • Several CCD (Prism 1A, 1B1)  From 3 to 6 CCD  CCD = ~4992 pixels * 16000 lines  Overlap = 32 pixels • One CCD (Prism 1B2R, 1B2G)  CCD = ~15000 pixels * 14000 lines • 4 Spectral Bands (Avnir2)  Band = ~7150 pixels * 8000 lines ESRIN - ARNAL Etienne

  9. Data Image DEM 3D results Alos Image Processing (2/5) • Imager: data reader for image generation For each pixel: • elaborates from the band values (0 to 255) applying sun angle correction and stretching to enhance image contrast, • extracts Tie Point (λ,φ) grid. It creates:  one image file (including all CCD/Bands),  one GeoTiff file (geolocalisation). ESRIN - ARNAL Etienne

  10. Data Image DEM 3D results Alos Image Processing (3/5) • Prism Nadir 1B2R Shizuoka, Japan on February 14, 2006 ESRIN - ARNAL Etienne

  11. Data Image DEM 3D results Alos Image Processing (4/5) • Avnir2 Tanegashima Is., Japan on February 17, 2006 ESRIN - ARNAL Etienne

  12. Data Image DEM 3D results Alos Image Processing (5/5) • encountered problems  Avnir2, ±5 pixels between each columns.  Prism and Avnir2, geolocalisation error.  Prism, many artifacts.  Prism and Avnir 1B2(R/G), nothing about time in the data. ESRIN - ARNAL Etienne

  13. Data Image DEM 3D results Digital Elevation Model (1/10) • Stereoscopy 3D, imager process. • For each pixel [I,J], Find the value of pixel Nadir [I,J] and [λ,φ]=fN(I,J) Find the value of pixel Backward fB-1[λ,φ] Find the value of pixel Forward fF-1[λ,φ] • Output: one RGB image with R=Nadir, G=Forward and B=Backward. ESRIN - ARNAL Etienne

  14. Data Image DEM 3D results Digital Elevation Model (2/10) • DEM, bases  Height is proportional to the along track displacement. Nadir Satellite track Forward ESRIN - ARNAL Etienne

  15. Data Image DEM 3D results Digital Elevation Model (3/10) • DEM, base equation ∆ is a multiple of the ground resolution ESRIN - ARNAL Etienne

  16. Data Image DEM 3D results Digital Elevation Model (4/10) • DEM Algorithm. • Image adjustments Forward Nadir Backward Mean = 35 STD = 3.4398 Mean = 43 STD = 2.4389 Mean = 57 STD = 2.5302 ESRIN - ARNAL Etienne

  17. Data Image DEM 3D results Digital Elevation Model (5/10) • DEM Algorithm. • Image adjustments, • Generate pyramid image, with gradually degraded resolution. Pass the matched points to the higher resolution level for fine matching. ESRIN - ARNAL Etienne

  18. Data Image DEM 3D results Digital Elevation Model (6/10) • DEM Algorithm. • Image rectification, • Generate pyramid image, • Feature matching, ESRIN - ARNAL Etienne

  19. Data Image DEM 3D results Digital Elevation Model (7/10) • DEM Algorithm. • Image rectification, • Generate pyramid image, • Feature matching, • Matching results, 1/16 1/8 1/4 1/1 1/2 ESRIN - ARNAL Etienne

  20. Data Image DEM 3D results Digital Elevation Model (8/10) • DEM Algorithm. • Image rectification, • Generate pyramid image, • Feature matching, • Matching results, • Filtering. Median filter, reduce noise (peaks): Mean filter, reduce high frequencies: ESRIN - ARNAL Etienne

  21. Data Image DEM 3D results Digital Elevation Model (9/10) • Integration in eogrid.esrin.esa.int. • Modification for Linux (no graphics), • Installation of Matlab Component Runtime, • Compilation of Matlab code (Stand-alone application). • Integrated new “DEM” application in G-POD in < 1 day ESRIN - ARNAL Etienne

  22. ESRIN - ARNAL Etienne

  23. Data Image DEM 3D results Digital Elevation Model (10/10) • encountered problems • Co-registration is corrected manually due to ALOS processors geo-referencing problem • Result of matching requires validation of the correlation distribution  not trivial • Correlation is impaired by high height gradients in image (e.g. buildings)  possible solution to weight the matching window with distance to centre • Patterns oriented along-track have low correlation contrast • Moving objects (cars, boats, troy horses, etc) • Sun glint creates big differences between views • Image radiometric quality (e.g. striping, spurious saturation artifacts) • Image boundaries ESRIN - ARNAL Etienne

  24. Data Image DEM 3D results 3D results • Japan, Shizuoka and surroundings, 02/14/2006. • AATSR Hurricane Jeanne, 20/09/2004 • Stereoscopic views. • Digital Elevation models. ESRIN - ARNAL Etienne

  25. Potential Enhancements • Investigate alternative matching methods for high gradient terrains (e.g. parallax, urban areas) • Make adaptive algorithm e.g. apply dynamically different techniques/parameters depending on correlation contrast observed • Integrate automatic co-registration of the 3 views with a good geo-referencing. • Add possibility to correlate several bands in parallel (e.g. AATSR dual views with 4 channels) • Include DEM geo-coding in last stage • Optimize algorithm for performance in multi-processing environment (e.g. tiling) • Calibration & Validation ! ESRIN - ARNAL Etienne

  26. Data Image DEM 3D results Thanks • Olivier Colin, • Jerome Louis, • Philippe Goryl, • Peter Reinartz (DLR), • Nityaporn Sirikan, • Patrick Grimont, • Emmanuel Mathot. Questions ? ESRIN - ARNAL Etienne

More Related