Try a public elevation map in QGIS

About ten minutes. Requires QGIS; no ArrayBridge account, repository checkout or live connector. This exercise uses the public USGS 3DEP fixture retained for our CRS qualification. The live connector was tested with Mac QGIS 4.2.2; this independent GeoTIFF exercise uses ordinary QGIS layers.

Download the original evidence

Download the USGS Boulder fixture ZIP and extract it. It contains the original 32×32 and 64×64 GeoTIFFs, service requests/responses, metadata, acquisition checksums and numerical exports. The file is hosted with these docs so the exercise does not depend on a temporary service download URL.

ZIP SHA-256:

421b0839a2678a211c9c3ed2959632f8de6e63b8e533ad3d1397668b80b113bd

These are service-resampled elevation extracts of the same area near Boulder, Colorado. They are not full-resolution survey data and are not authored by ResInsight. The fixture records the USGS service, USGS product/rights information and vertical-reference specification. Horizontal CRS is EPSG:4326; vertical metadata declares NAVD88 meters, positive upward. We have not independently surveyed the heights.

Compare display coordinate systems

1. Open a new QGIS project and add elevation-32.tif by dragging it onto the map.
2. Inspect the layer’s information: its CRS should be EPSG:4326. Do not relabel it.
3. Select EPSG:4326 as the project CRS using QGIS’s project CRS control, then zoom to the layer.
4. Change only the project CRS to EPSG:3857. The map is redrawn in projected coordinates; its stored pixels and layer CRS remain unchanged.
5. Add elevation-64.tif and compare the layers by toggling visibility. Both cover the same requested area at different sampling resolutions. This difference does not show terrain changing over time.

This proves independent reading and illustrates QGIS display reprojection. It does not run ArrayBridge’s derived-raster conversion or subscription pipeline.

Try ArrayBridge’s conversion or live pilot

Developers with a checkout can build, convert and verify the retained fixture without a server. The derived representation uses EPSG:3857, explicit 100-meter target-grid spacing and nearest-neighbor resampling. Web Mercator grid spacing is not uniform ground-distance accuracy.

In the operator-provisioned live CRS demo, QGIS displays the EPSG:3857 raster in an EPSG:4326 project alongside an original request-footprint layer. Switching the project CRS changes display only; advancing the fixture publishes a new revision and moves follow while pin stays fixed. The demo alternates the two retained resolutions, not real-time USGS terrain observations.

Understand the three CRS settings · Live-map controls · Availability.