Collecting training data

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(Created page with "Non-statistical based selection = = Prepare sources for reference data collection = # Load a LUC classification map of the Urban European Atlas for Göttingen in vector format...")
 
(→‎Create a new vector layer)
 
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Non-statistical based selection =
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= Non-statistical based selection =
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= Prepare sources for reference data collection =
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== 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]]).
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# 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]])
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# 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,B4 =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}}.
 
# Right click on the satellite image file name in Layers window. {{mitem|text=Layer CRS --> Set Project CRS from Layer}}.
  
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= Create a new vector layer =
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== Create a new vector layer ==
 
# 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}}.  
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#* Click the {{button|text=Specify CRS}} button and select the Project CRS, e.g.: WGS84 / UTM32N (EPSG:32632).
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#* Click the {{button|text=Specify CRS}} button and select the Project CRS: EPSG:32632 - WGS84 / UTM32N.
 
#* Adding an additional column in the attibute table:  
 
#* Adding an additional column in the attibute table:  
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#** For the attribute's name type {{typed|text=C_ID}} into the {{button|text=Name}} field of the {{button|text=New attribute}} section.
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#** For the attribute's name type {{typed|text=C_ID}} into the {{button|text=Name}} field of the {{button|text=New field}} section.
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#** Select {{button|text=Whole number (integer)}} as data type.
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#** Select {{button|text=Whole number (integer)}} as Type.
 
#** Confirm with {{button|text=Add to Fields List}}. {{button|text=OK}}.
 
#** Confirm with {{button|text=Add to Fields List}}. {{button|text=OK}}.
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[[File:qgis_add_new_vector_layer.png|400px]]
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[[File:qgis_add_new_poly_vector_layer.png|400px]]
  
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= Configure vector digitizing =
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== Configure vector digitizing ==
 
# Select {{mitem|text=Project --> Snapping options}}.
 
# Select {{mitem|text=Project --> Snapping options}}.
 
# Activate Snapping clicking on [[File:Qgis_snapping_button.png]].  
 
# Activate Snapping clicking on [[File:Qgis_snapping_button.png]].  
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[[file:Qgis_snap_opt.png|800px]]
 
[[file:Qgis_snap_opt.png|800px]]
  
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= Start digitizing =
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== 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]].
 
# 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]].
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# Let#s start with Land cover class ''' Water'''.  Use the European Urban Atlas to find water bodies. Zoom in to a lake.  
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# 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.  
 
# 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}}
 
# Enter the LUC class in the C_ID field. {{button|text=OK}}

Latest revision as of 05:27, 6 June 2022

Contents

[edit] Non-statistical based selection

[edit] Prepare sources for reference data collection

  1. Load a LUC classification map of the Urban European Atlas for Göttingen in vector format. (Loading vector data)
  2. Load Digital aerial Ortho Photos (DOP) published as "Google Satellite". (Load a WMS-Layer).
  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,B4 =7,9,3). (Changing Raster Layer Style)
  4. Right click on the satellite image file name in Layers window. Layer CRS --> Set Project CRS from Layer.

[edit] Create a new vector layer

  1. Select Layer --> Create Layer --> New Geopackage Layer.
  2. Define path and file name.
    • As Geometry type, select Polygon.
    • Click the Specify CRS button and select the Project CRS: EPSG:32632 - WGS84 / UTM32N.
    • Adding an additional column in the attibute table:
      • For the attribute's name type C_ID into the Name field of the New field section.
      • Select Whole number (integer) as Type.
      • Confirm with Add to Fields List. OK.

Qgis add new poly vector layer.png

[edit] Configure vector digitizing

  1. Select Project --> Snapping options.
  2. Activate Snapping clicking on Qgis snapping button.png.
  3. Change the dropdown list All Layers to Advanced Configuration
  4. Activate the checkbox of a vector layer for which you wish to configure snapping.
  5. Click in the Type column of the vector layer. In the dropdown list activate Vertex and Segment.
  6. Choose Units meters.
  7. Select the snapping Tolerance 2(meters).
  8. Activate the checkbox Avoid overlap.
  9. Activate Topological Editing and Snapping on Intersection

Qgis snap opt.png

[edit] Start digitizing

  1. Mark the new vector file in the Layers window. Start the edit mode by clicking the Toggle editing button QGIS 2.0 Edit.png.
  2. Let's start with land cover class Water. Use the European Urban Atlas to find water bodies. Zoom in to a lake.
  3. Click Add feature QGIS 2.0 Addpolygon.png to start digitizing. Start drawing polygons with left click. Finish the geometry by right-clicking.
  4. Enter the LUC class in the C_ID field. OK

Qgis digitizing.png

You may always delete a polygon by simply clicking Cancel in the attributes dialogue, or by selecting it QGIS 2.0 Select.png and deleting with the Delete selected QGIS 2.0 Delete selected.png button. Save your edits by clicking at times on Qgis save edits button.png. Finish the edit mode by clicking Toggle editing QGIS 2.0 Edit.png.

Retrieved from "http://wiki.awf.forst.uni-goettingen.de/wiki/index.php?title=Collecting_training_data&oldid=16514"
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