Instructions for Covariate Extraction
- Configure Global Settings
- Camera Trap Covariate Settings:
- Set buffer around camera traps for value extraction
- Choose whether to use bilinear interpolation
- Preview map shows camera locations and buffer
- Prediction Raster Settings:
- Choose prediction area: no clipping, camera trap grid, study area, or their intersection
- Set buffer for prediction area (up to 500m for 'no clipping' option)
- Upload raster template (optional) or specify resolution
- Preview map shows selected extent with interactive basemap
- Choose Data Source
- Local Rasters:
- Choose directory containing your covariate rasters, or
- Specify individual raster files
- Set file format (default: .tif)
- Enable recursive search if rasters are in subdirectories
- Elevation & Terrain:
- Downloads elevation data from AWS Terrain Tiles
- Choose zoom level for resolution (z10: ~80m, z11: ~40m, z12: ~20m)
- Select which terrain indices to calculate (slope, aspect, TRI, TPI, roughness)
- Processing Behavior
- Values at camera locations are always extracted from original resolution data
- Prediction rasters are created based on:
- Provided template if available
- Otherwise, existing prediction rasters if available
- Otherwise, specified resolution if provided
- If no specifications given, local rasters will not create prediction rasters and elevation data will use source resolution
- Prediction rasters are masked to selected extent if clipping is requested
- Output
- Covariate values are added to the camera trap table
- Original rasters are stored at their native resolution
- Prediction rasters are created according to specifications
- All covariate data can be cleared at once using the 'Clear All Covariates' button
Notes:
- Large rasters or numerous covariates may take some time to process
- When using elevation data, a minimum 5km buffer is applied for download to ensure proper terrain calculations
- The preview maps update in real-time to show the impact of your buffer and prediction area settings
- You can process local rasters and elevation data independently
- Clearing covariates removes all added columns from the camera trap table and clears both original and prediction rasters