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

Centre for Geo-information Geo-information cycle “real” land use validation error matrix source:

Centre for Geo-information Solution: fieldwork

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

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

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

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

Centre for Geo-information Example 3: global land use

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

Centre for Geo-information 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 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 Validation plan Spatial model Real world Validation plan Fieldwork Evaluation Structured description of validation methodology for a specified spatial model and a specified domain of application Descriptive, reproducible, from general to detailed

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

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

Centre for Geo-information 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 Available data and equipment See website: Under Fieldwork/case studies

Centre for Geo-information 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 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