1 / 22

Fieldwork: the role of validation in geo-information science

Fieldwork: the role of validation in geo-information science. Lammert Kooistra Contact: Lammert.Kooistra@wur.nl. RS&GIS Integration Course (GRS-30806). “real”. land use. error matrix. validation. Geo-information cycle. source: www.lgn.nl. Solution: fieldwork. Overview.

jessamine-blanchard
Télécharger la présentation

Fieldwork: the role of validation in geo-information science

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. Fieldwork: the role of validation in geo-information science Lammert Kooistra Contact: Lammert.Kooistra@wur.nl RS&GIS Integration Course (GRS-30806) Centre for Geo-information

  2. “real” land use error matrix validation Geo-information cycle source: www.lgn.nl Centre for Geo-information

  3. Solution: fieldwork Centre for Geo-information

  4. Overview Fieldwork assignment (lecture 1) • Theory of validation • Validation in practice: the validation plan • The fieldwork assignment • Case studies • Available datasets and equipment • Planning • Role, communication & contact with coach Writing a scientific paper (lecture 2) Practical issues (lecture 3) Centre for Geo-information

  5. (geo-spatial) model development cycle landscape openness MODIS NDVI source: Sargent (1998) Centre for Geo-information

  6. Definition of validation • Modeling domain (GMP Manual Part 1 (p. 3-7)): validation is used to check the suitability of the model to simulate an independent data set (i.e. not used in calibration) • RS domain (CEOS WGCV): validation is the process of assessing by independent means the quality of the data products derived from the system outputs (from Liang, 2004) • Spatial modeling domain (Sargent, 1998): substantiation that a computerized model within its domain of applicability possesses a satisfactory range of accuracy consistent with the intended application of the model • verification (Sargent, 1998): ensuring that the computer program of the computerized model and its implementation are correct Centre for Geo-information

  7. Operational validation classification source: Sargent (1998) Operational validity • Returns measure of accuracy • Of interest for end-user • Assessment of processing algorithms • Determination of sources of uncertainty Centre for Geo-information

  8. Example 1: landscape enclosure • Comparison of spaciousness: • field and photograph observed • calculated with model (topographic features) source: Palmer&Roos (1998) Centre for Geo-information

  9. Example 2: MODIS LAI 2. sampling in 1 x 1 km area 3. comparison of MODIS based LAI with field LAI 1. study area: savanna source: Tian et al., 2002 Centre for Geo-information

  10. Example 3: global land use • http://www.confluence.org Centre for Geo-information

  11. Validation and scaling Example of fieldwork activities: field spectroscopy, hemispherical camera, species composition Example of flux tower in the field (above) and distribution of RS based observation net- works over the globe (left) Centre for Geo-information

  12. Fieldwork assignment • Investigate role of validation in geo-information cycle based on a case study for the Achterhoek area. The final result of this assignment is an individual paper. • Activities: • Introduction to case study (= spatial model) • Preparation of validation plan • Make field measurements • Analyze results • Write individual paper Centre for Geo-information

  13. Case studies • Group 1: Validating visibility measures to estimate perceived landscape openness (Gerd Weitkamp) • Group 2: Remote sensing based mapping of biomass and canopy water content for natural grassland ecosystems (Lammert Kooistra) • Group 3: Sensing recreational use of the environment (Arend Ligtenberg) • Group 4: Characterization of vegetation roughness using 3D-GPS (John Stuiver) • Group 5: Remote sensing based monitoring of Natura2000 area Korenburgerveen (Harm Bartholomeus) • Group 6: Accuracy assessment of the LGN land cover data base for the Netherlands (Jan Clevers) Centre for Geo-information

  14. Validation plan • Structured description of validation methodology for a specified spatial model and a specified domain of application • Descriptive, reproducible, from general to detailed • http://eospso.gsfc.nasa.gov/validation/terraval.php • http://www.daac.ornl.gov/DAAC/PI/bestprac.html Spatial model Real world Validation plan Evaluation Fieldwork Centre for Geo-information

  15. Components of a validation plan • Which (geo-spatial) model • Which (independent) variables • Which quality parameter • Which sampling scheme • Which spatial and temporal extent • Which (geo) data • Which (field) instruments • Which measurement protocols • Which field forms • Schematic presentation of methodology in flow chart Centre for Geo-information

  16. Validation plan: background and objective • Which (spatial) model • Which (independent) variable(s) will be validated • Which quality parameter: evaluation • Formalize complete methodology in flowchart Centre for Geo-information

  17. Validation plan: sampling strategy • Which sampling scheme • Which spatial and temporal extent • Locations • Measurements in time • Stratification • Prior knowledge/data Centre for Geo-information

  18. Validation plan: data and instrumentation • Which (geo) data • Which (field) instruments Centre for Geo-information

  19. Validation plan: implementation • Which measurement protocols • Which field forms • Preparation of (digital) field maps During fieldwork: • Store and back-up data • First check of results in “field office” Centre for Geo-information

  20. Available data and equipment • See website: http://webgrs.wur.nl/cgi/courses/grs30806/ • Under Fieldwork/case studies Centre for Geo-information

  21. Planning • Preparation in Wageningen: 3, 5 and 6 June: • Introduction to case study • Preparation of validation plan (incl., data and instruments) • Feedback from coach • Fieldwork in Achterhoek: 8 June (19:00) – 13 June • Arrival Sunday June 10 from 19:00 • Reconnaissance study area + testing instruments • Test measurement protocols • Measurements according to validation protocol • Check and first analysis of results • Field presentation of results: feedback from coaches • Paper writing in Wageningen: 17 June – 27 June Centre for Geo-information

  22. Role, communication & contact with coach • Providing students with background information and knowledge on topic • Judge the validation plan during the preparation week • Assist and provide feedback during fieldwork week • Judge results of field presentation and give feedback • If required assist students during elaboration of results • Judge the final result of case study: the individual papers Centre for Geo-information

More Related