Training data selection (manually)
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= Prepare sources for reference data collection = | = 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 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 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). | + | # 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. {{mitem|text=Layer CRS --> Set Project CRS from Layer}}. | ||
= Create a new vector layer = | = Create a new vector layer = | ||
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# Select {{mitem|text=Layer --> Create Layer --> New Geopackage Layer}}. | # Select {{mitem|text=Layer --> Create Layer --> New Geopackage Layer}}. | ||
# Define path and file name. | # Define path and file name. | ||
#* As Geometry type, select {{button|text=Polygon}}. | #* As Geometry type, select {{button|text=Polygon}}. | ||
− | #* Click the {{button|text=Specify CRS}} button and select the Project CRS, e.g.: WGS84/UTM32N (EPSG:32632). | + | #* Click the {{button|text=Specify CRS}} button and select the Project CRS, e.g.: WGS84 / UTM32N (EPSG:32632). |
#* Adding an additional column in the attibute table: | #* Adding an additional column in the attibute table: | ||
− | #** For the attribute's name type {{typed|text= | + | #** For the attribute's name type {{typed|text=C_ID}} into the {{button|text=Name}} field of the {{button|text=New attribute}} section. |
#** Select {{button|text=Whole number (integer)}} as data type. | #** Select {{button|text=Whole number (integer)}} as data type. | ||
− | #** Confirm with {{button|text=Add to Fields List}}. | + | #** Confirm with {{button|text=Add to Fields List}}. {{button|text=OK}}. |
[[File:qgis_add_new_vector_layer.png|400px]] | [[File:qgis_add_new_vector_layer.png|400px]] | ||
= Configure vector digitizing = | = Configure vector digitizing = | ||
# Select {{mitem|text=Project --> Snapping options}}. | # Select {{mitem|text=Project --> Snapping options}}. | ||
− | # Activate Snapping clicking on | + | # Activate Snapping clicking on [[File:Qgis_snapping_button.png]]. |
− | # Change {{button|text=All Layers}} to {{button|text=Advanced Configuration}} | + | # Change the dropdown list {{button|text=All Layers}} to {{button|text=Advanced Configuration}} |
− | # Activate | + | # Activate the checkbox of a vector layer for which you wish to configure snapping. |
− | # | + | # Click in the '''Type''' column of the vector layer. In the dropdown list activate {{button|text=Vertex}} and {{button|text=Segment}}. |
# Choose '''Units''' {{button|text=meters}}. | # Choose '''Units''' {{button|text=meters}}. | ||
− | # Select the snapping '''Tolerance''' {{typed|text= | + | # Select the snapping '''Tolerance''' {{typed|text=2}}(meters). |
# Activate the checkbox '''Avoid overlap'''. | # Activate the checkbox '''Avoid overlap'''. | ||
# Activate {{button|text=Topological Editing}} and {{button|text=Snapping on Intersection}} | # Activate {{button|text=Topological Editing}} and {{button|text=Snapping on Intersection}} | ||
− | [[file:Qgis_snap_opt.png| | + | [[file:Qgis_snap_opt.png|800px]] |
= Start digitizing = | = Start digitizing = | ||
− | + | # Mark the new vector file in the Layers window. Start the edit mode by clicking the {{button|text=Toggle editing}} button [[file:QGIS_2.0_Edit.png|25px]]. | |
+ | # Let#s start with Land cover class ''' Water'''. Use the European Urban Atlas to find water bodies. Zoom in to a lake. | ||
+ | # Click {{button|text=Add feature}} [[file:QGIS_2.0_Addpolygon.png|25px]] to start digitizing. Start drawing polygons with left click. Finish the geometry by right-clicking. | ||
+ | # Enter the LUC class in the C_ID field. {{button|text=OK}} | ||
− | [[ | + | [[file:Qgis_digitizing.png|800px]] |
+ | |||
+ | You may always delete a polygon by simply clicking {{button|text=Cancel}} in the attributes dialogue, or by selecting it [[file:QGIS_2.0_Select.png|25px]] and deleting with the {{button|text=Delete selected}} [[file:QGIS_2.0_Delete_selected.png|25px]] button. | ||
+ | Save your edits by clicking at times on [[file:Qgis_save_edits_button.png]]. | ||
+ | Finish the edit mode by clicking {{button|text=Toggle editing}} [[file:QGIS_2.0_Edit.png|25px]]. |
Latest revision as of 15:41, 24 November 2020
Contents |
[edit] 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.
[edit] 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.
[edit] Configure vector digitizing
- Select Project --> Snapping options.
- Activate Snapping clicking on .
- Change the dropdown list All Layers to Advanced Configuration
- Activate the checkbox of a vector layer for which you wish to configure snapping.
- Click in the Type column of the vector layer. In the dropdown list activate Vertex and Segment.
- Choose Units meters.
- Select the snapping Tolerance 2(meters).
- Activate the checkbox Avoid overlap.
- Activate Topological Editing and Snapping on Intersection
[edit] Start digitizing
- Mark the new vector file in the Layers window. Start the edit mode by clicking the Toggle editing button .
- Let#s start with Land cover class Water. Use the European Urban Atlas to find water bodies. Zoom in to a lake.
- Click Add feature to start digitizing. Start drawing polygons with left click. Finish the geometry by right-clicking.
- Enter the LUC class in the C_ID field. OK
You may always delete a polygon by simply clicking Cancel in the attributes dialogue, or by selecting it and deleting with the Delete selected button. Save your edits by clicking at times on . Finish the edit mode by clicking Toggle editing .