A prototype tile server that can overlay a local COG on a proxied global layer.

Eventually, we will extend and integrate this capability with other tools.

This is configured to work with a local or remotely stored COG and a global layer which will be used to fill in data gaps.

Using the service

• Provide a COG URL using the x-overlay-layer query parameter.
• Provide a global overlay URL using the x-fallback-layer query parameter.

The fallback layer defaults to Mapbox Terrain DEM if not specified, or it can be set usign the FALLBACK_LAYER environment variable. The suffix {z}/{x}/{y}.{ext} is appended to layer URLs to fetch tiles.

TODO

• Integrate with JSON Web Token (JWT) authentication
• More flexibility in service configuration
• More options for image processing
• Serve COG footprints