Work Package Radiometry

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1 Work Package Radiometry EuroSDR project Radiometric aspects of digital photogrammetric imagery Eija Honkavaara Department of Remote Sensing and Photogrammetry Finnish Geodetic Institute EuroDAC Core Team Meeting Progress EuroSDR Radiometric aspects of digital photogrammetric imagery analysis of review results Manuscript draft submitted to co-authors Will be submitted to some Journal, maybe open access Remote Sensing and to ISPRS Hannover Workshop EuroDAC Core Team Meeting Finnish Geodetic Institute 2

2 EuroSDR radiometry query 8 replies 5 data providers 6 data users 2 research organizations 1 software company 1 sensor manufacturer EuroDAC Core Team Meeting Finnish Geodetic Institute 3 Stakeholders Type Sensor Software Data Provider Applications Research Images Products U1 x x x x x U2 x x x x U3 x x x U4 x x U5 x P1 x x x P2 x x x x P3 x P2 x x R1 x SW1 x x M1 x x EuroDAC Core Team Meeting Finnish Geodetic Institute 4

3 Participants Participant Abbreviation Organization Group Role Institut Cartogràphic ICC NMA U2 Software developer Catalonia Data provider Institut Géographique National, France Data user IGN NMA U1 Sensor manufacturer Software developer Data provider Data user National Survey and KMS NMA U4 Data user Cadastre, Denmark National Land Survey, Finland NLS, NMA U3 Data provider Data user Ordnance Survey, Great Britain OS NMA U3 Data provider Data user Swisstopo, Swizerland Swisstopo NMA U3 Data provider Data user ReSe Applications ReSe Company SW1, R1 Software, consultant Scläpfer, Swizerland Finnish Geodetic FGI Research R1 Research Institute, Finland organization Institut für Geoinformatik und Fernerkundung, Universität Osanbrük IGF University R1 Research EuroDAC Core Team Meeting Finnish Geodetic Institute 5 Sensors DMC, ADS40, IGN Desired improvements Additional channels, no spectral overlap Wider image format Pansharpening factor, multihead images DMC: PAN, NIR ADS40: 2 deg separation of PAN and MS Lossy compression EuroDAC Core Team Meeting Finnish Geodetic Institute 6

4 Calibration Exclusively based on laboratory calibration Limitations/desired improvements Missing parameters (e.g. Absolute calibration, thermal and electronic noise, accuracy indicators) DMC: only relative calibration, different for each MSchannel -> no true color Laboratory calibration the basis, other methods necessary Test field calibration: manufacturer, data provider Self-calibration, in-flight calibration, platform calibration Specifications for methods necessary EuroDAC Core Team Meeting Finnish Geodetic Institute 7 Data collection GSD 5 cm -> Exposure settings, DMC Intergraphs FMS: light value -> f-stop, exposure time CCNS: automatic settings IGN: Fixed aperture, varying exposure Flight conditions Clear atmosphere, no clouds Visibility 15 km Minimum solar elevation? On the fly quality control DMC: Cloud cover from video images, image quality from sample of collected images IGN: saturated areas from collected images In-situ measurements: no reference targets, no atmospheric state EuroDAC Core Team Meeting Finnish Geodetic Institute 8

5 Data collection Desired situation Efficient tools for exposure control: fast opening of images, quick checks of all images, statistics NLS: great problems in finding correct exposure Atmospheric/illumination observations during image collection (radiance sensors, additional channels) Specifications for reflectance reference targets and in-situ measurements EuroDAC Core Team Meeting Finnish Geodetic Institute 9 Mission design Mission preparation Image acquisition Image collection Post-processing Referencing Georeferencing Calibration Measurement and interpretation GIS Restoration Measurement Radiometric correction Interpretation EuroDAC Core Team Meeting Finnish Geodetic Institute 10

6 Post processing Image acquisition system vs. Image product generation system System correction by manufacturer software Image product generation application dependent: orthophots, stereomodels, quantitative images Visual applications pansharpening, 8 bit/pixel/channel Approaches for radiometric correction Radiometric block adjustment software (Leica, ICC, IGN) Photogrammetric software: Socet Set Dodger, Orthovista, General image processing: Agfa Apertune, Photoshop Quantitative applications: no pansharpening, e.g. Vegetation indices Quality control EuroDAC Core Team Meeting Finnish Geodetic Institute 11 Post-processing Limitations/desired situation Image acquisition: system corrected radiance image Image product generaiton: reflectance image, true color image Radiometric/colorimetric correction Radiometric block adjustment: improvement, research Automatic and efficient post-processing Minimizing geometric transformations, headers Interactive tools, graphical displays Batch processing Traceability and comparability of images EuroDAC Core Team Meeting Finnish Geodetic Institute 12

7 Utilization of images Orthophotos, stereomodels, 3D and 2D mapping IGN, ICC: classification Desired situation: Better radiometric processing Automatic and efficient image processing Better visual image qualyt More accurate classifications EuroDAC Core Team Meeting Finnish Geodetic Institute 13 Radiometrically controlled photogrammetric test flights Acceptance testing of NLS DMC with Siemens star, BRF targets, natural reference targets, insitu radiance/reflectance measurements and variois exposure and aperture settings Difficulties Scheduled: Beginning of August, realization 1.9, months ready to go, 3 unnecessary field campaigns Campaign 1.9: Improper exposure settings -> over exposure Campaign 25.9: not insitu measurements, no Siemens star No imagery from urban area test site due to flight restrictions EuroDAC Core Team Meeting Finnish Geodetic Institute 14

8 EuroDAC Core Team Meeting Finnish Geodetic Institute 15 test flights ADS40+ALS50, GSD: 10, 20, 30, 40 cm Hyytiälä forestry test field: more than 200 forestry plots, known trees, permanent state-of-the-art weather station with sunphotometer (Nasa SMEAR) BRF targets, natural covers, radiance/reflectance measurements Difficulties: Poor weather conditions: one week ready to go, flight on Saturday Clouds after campaign: no BRF for natural targets Two passes to get full uncompressed data with 10 and 20 cm GSD Advantage: permanent weather station!!! EuroDAC Core Team Meeting Finnish Geodetic Institute 16

9 EuroDAC Core Team Meeting Finnish Geodetic Institute 17 Phase II Distribution of data set ICC Finland: DMC, ADS40 (?) Description of data sets, delivery to participants EuroCOW 2010 Radiometry workshop/day EuroDAC Core Team Meeting Finnish Geodetic Institute 18

10 Conclusions Radiometric processing in its infancy, requires considerable labour Stakeholders perspective Image user: e.g. Several sensors, different processes, different settings, subjective selections Data provider To obtain quantitative imagery the whole production chain has to be analysed: sensor, calibration, data collection, post-processing Development have taken place, but questions similar to those in Important actions: transparent documentation, calibration and processing; certification; standardization, INVESTIGATION EuroDAC Core Team Meeting Finnish Geodetic Institute 19