Training data selection (manually)
From AWF-Wiki
Contents |
Prepare sources for reference data collection
- Load a LUC classification map of the Urban European Atlas for Göttingen in vector format. (Loading vector data)
- Load Digital aerial Ortho Photos (DOP) published as "Google Satellite". (Load a WMS-Layer).
- Load a multiband (B2,B3,B4,B5,B6,B7,B8,B8A,B11,B12) Sentinel-2 satellite image and display a false color composite (RGB = B8,B11,B5 =7,9,3). (Changing Raster Layer Style)
- Right click on the satellite image file name in Layers window. Layer CRS --> Set Project CRS from Layer.
Create a new vector layer
- Select Layer --> Create Layer --> New Geopackage Layer.
- Define path and file name.
- As Geometry type, select Polygon.
- Click the Specify CRS button and select the Project CRS, e.g.: WGS84 / UTM32N (EPSG:32632).
- Adding an additional column in the attibute table:
- For the attribute's name type C_ID into the Name field of the New attribute section.
- Select Whole number (integer) as data type.
- Confirm with Add to Fields List. OK.
Configure vector digitizing
- Select Project --> Snapping options.
- Activate Snapping clicking on the left button.
- Change All Layers to Advanced Configuration
- Activate one or several vector layers for which you wish to configure snapping.
- Change Type from vertex to vertex and segment.
- Choose Units meters.
- Select the snapping Tolerance 0.2.
- Activate the checkbox Avoid overlap.
- Activate Topological Editing and Snapping on Intersection
Start digitizing
Digitize at least 10 training areas for each of Land cover class (C_ID) using the simplified classification scheme (s.below) and a MMU (minimum Mapping Unit) = 1600m2