Co-registration with SNAP
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= Stack single bands to multiband file = | = Stack single bands to multiband file = | ||
* Create a stack of all coregistered single bands. {{mitem|text=Raster --> Geometric --> Collocation}} | * Create a stack of all coregistered single bands. {{mitem|text=Raster --> Geometric --> Collocation}} | ||
| + | * Resampling: {{button|text=Bilinear Resampling}} | ||
[[File:snap_collocation.png|400px]] | [[File:snap_collocation.png|400px]] | ||
Revision as of 12:40, 16 November 2020
Contents |
Visualize geometric offset
- Start SNAP Desktop
- File --> Open Product.... Browse for Unmanned Aerial System (UAS) ortho mosaics:
\geodata\uas\clip_ebee_ortho_align.tif is a reference image which is very well georeferenced. \geodata\uas\clip_mavic_ortho_align.tif is an image with a positional offset. It needs to be registered to the reference image. Open or drag and drop marked files from Windows File Explorer into the SNAP Product Explorer tab.
- Mark the reference image clip_ebee_ortho_align.tif in ToC. Right click Open RGB Image Window --> OK.
- Mark the image to be registered clip_mavic_ortho_align.tif in ToC. Right click Open RGB Image Window --> OK.
- Window --> Tile Vertically. Both side-by-side windows are spatially linked. Zoom in and use the Panning tool to see the offset between both images
Split multiband to single band files
- Mark the image to be registered clip_mavic_ortho_align.tif in ToC. Raster --> Subset --> Band Subset. Check exclusivly band_1.
- Repeat this step for band_2 and band_3 creating separated single bands of the image to be registered .
Co-registration of single band raster files
- Raster --> Geometric operations --> GeFolki Co-registration.
- Define I/O Parameters and Processing Parameters:
- Click Run.
- Repeat this step for band_2 (subset_1) and band_3 (subset_2). Adjust processing parameters for each band, accordingly.
Stack single bands to multiband file
- Create a stack of all coregistered single bands. Raster --> Geometric --> Collocation
- Resampling: Bilinear Resampling
Convert data type from float32 to uint8
- Raster --> Data Conversion --> Convert Datatype
- Check Save as and select GeoTIFF from drop downlist.
- Target Data type: uint8
- Scaling: Linear (slope and intercept)
- Mark the coregistered image collocate_cnv in ToC. Right click Open RGB Image Window --> OK. Check the geometric quality of the co-registration comparing clip_ebee_ortho_align.tif (bottom), clip_ebee_ortho_align.tif (middle) and collocate_cnv.tif (top).
