1 / 24

Digital Resource Acquisition for USDA Planning Briefing

This briefing outlines the reasons for moving to digital resource acquisition in the USDA, including increased dynamic range, sharper images, and elimination of small businesses. It also discusses the types of digital cameras available and the requirements for ground resolution, end products, storage, and inspection.

dahlgren
Download Presentation

Digital Resource Acquisition for USDA Planning Briefing

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. Digital Resource Acquisition John Mootz, APFO Charlotte Vanderbilt, APFO

  2. Why move to digital? • Multi-Spectral • Panchromatic • Natural color • Near Color IR USDA Planning Briefing

  3. Why move to digital? (Con’t) • Increase in dynamic range (12-bit) • More shadow detail • 8-bit only contains 6.25% of 12-bit values • Some benefit with 8-bit deliverable 8-bit: 256 values 12-bit: 4,096 values USDA Planning Briefing

  4. Why move to digital? (Con’t) • Sharper images • First generation (no scanning) • No dust, lint, or scratches • Better geometric resolution • Simple AT process • Limited control requirement • Requires IMU/Airborne GPS systems USDA Planning Briefing

  5. Why stay with film? • Storage needs for digital products • No film to “fall back to” • No cheap contact prints • Inkjet vs “photographic” prints • Slight increase in cost for stereo • Difference should be eliminated soon • Min difference when creating ortho NO SIGNIFICANT SCHEDULE BENEFIT USDA Planning Briefing

  6. Elimination of Small Businesses • Digital cameras are very expensive • ADS40: ~$1.2M • DMC: ~$800k • DSS: $300-350k • Having a single camera adds risk • Camera cost is only a small element • Software, storage, IT equipment, etc USDA Planning Briefing

  7. Types of Digital Cameras • Small format cameras • do not meet resolution or geometric accuracy requirements • Medium format cameras • Small collection area (footprint) • Most cannot capture multi-spectral • Large format “mapping” cameras • Push-broom sensor • Frame based sensor Intergraph DMC Applanix DSS 422 Nikon D40 USDA Planning Briefing

  8. Small format Camera Bayer pattern USDA Planning Briefing

  9. Push-broom sensor • Minimizes “building lean” in flight direction • Heavily dependent on GPS/IMU USDA Planning Briefing

  10. Exterior orientation w X f Y k Z Push-broom sensor (Con’t) USDA Planning Briefing

  11. Push-broom sensor (Con’t) Level 0 (Raw data) Level 1 (Rectified) USDA Planning Briefing

  12. Frame-based sensor • Same workflow as film-based • Typically uses multiple heads and is pan sharpen Multiple high resolution CCD heads (4 pan and 4 color) USDA Planning Briefing

  13. Multiple Head Cameras 4 pan sensors are mosaick using tie points Combined with “color” sensors USDA Planning Briefing

  14. Pan-sharpening • Mosaick the 4 pan • Registration the 4 MS • Upsample color • Co-register pan to G channel • RGB -> HSV • Replace V channel with pan • HSV -> RGB 3) USDA Planning Briefing

  15. Radiometric Sensitivity Ideal bands for remote sensing applications should be narrow and non-overlapping, whereas the requirement for high quality true-colour images dictates broad, overlapping bands. USDA Planning Briefing

  16. What is the requirements? • Ground Resolution • End product • Data format • Metadata and other products • Storage • Inspection USDA Planning Briefing

  17. Ground Resolution • Digital imagery uses GSD • To compare to traditional film scale, we need to consider scanning resolution: Scale25 micron 1:7,920 8 in (20cm) 1:12,000 1 ft (30cm) 1:15,840 1.3 ft (40cm) 1:24,000 2 ft (60cm) USDA Planning Briefing

  18. 3 foot Western ID 1 foot USDA Planning Briefing

  19. End Product • Footprint? • Original camera footprint • USGS quarter-quad • Level of Georeferencing? • None • Single point • “Rubber sheeted” • Full ortho USDA Planning Briefing

  20. End Product (Con’t) • Mosaick? • Radiometric Balanced? • Coverage? • Stereo pairs • 3D viewing requires AT solution USDA Planning Briefing

  21. Metadata and Other products • AT solution • Viewing software dependant • Raw imagery for remote sensing • Not “geoprocessed” or “radiometrically corrected” • GPS and IMU data • Multiple formats USDA Planning Briefing

  22. Storage • Who will be responsible for storage • APFO has storage film • Public access via…? USDA Planning Briefing

  23. Inspection • New inspection process will need to be established • No current specification for products • Stereo pairs • AT solutions • GPS/IMU data USDA Planning Briefing

  24. Resource Ortho Issues • Accurate ortho comes from an accurate digital elevation model • Pixel resolution for imagery is only as good as the quality and accuracy of the terrain model and local control points (geodetic network) • Bottom line: • NED may not be accurate enough • Ground control is going to add cost USDA Planning Briefing

More Related