ustopo-qmapshack¶
The US Topo sheets as one seamless QMapShack map, collars cropped
- Version recorded: station
- Categories:
navigation-maps - Upstream: https://gdal.org/
- Needs first:
usgs-ustopo,gdal-bin
What it does¶
Turns the US Topo sheets into one map QMapShack can open, under /usr/local/share/hammunition/data/ustopo-qmapshack/: each sheet reprojected to Web Mercator and cropped to its own quadrangle, so the white margin and legend around every printed sheet are gone and neighbouring sheets meet edge to edge, with overviews so it draws quickly zoomed out; then ustopo.vrt, one virtual raster over all of them, which the qmapshack-offline launcher adds to QMapShack's map list. If you have installed the Forest Service's FSTopo sheets (hammunition install usfs-fstopo, by name only), they become a second map in the same directory, FSTopo.vrt: each sheet's colour palette expanded to RGB, tiled and given overviews (the sheets come as strips with no overviews, and a mosaic of differing palettes keeps only the first one's colours).
Why you would want it¶
A US Topo GeoTIFF is the whole printed page, each in its own projection; QMapShack cannot lay them side by side as they come, and stacked uncropped each margin hides its neighbour. This makes them one map, with the archive's GDAL and nothing else.
Before it will work¶
usgs-ustopo and gdal-bin, which install first. usfs-fstopo is read when installed and never pulled in.
How it installs¶
- converted from usgs-ustopo by ustopo-mosaic (Public domain (USGS), https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits)
Known problems¶
Measured on one Delaware sheet on 2026-09-29: 2.5 s to warp a 9.2 MB sheet to 6.0 MB and 0.9 s to add overviews, 8.9 MB in all; the plan estimates the same size as the download, measured on one quad. Keeping the downloaded sheets and the warped ones about doubles the disk the sheets take. QMapShack showing this map has not been measured yet: in the one run so far QMapShack opened the VRT and listed it, and the map area stayed blank for a reason not found. If it stays blank for you, see the guide's troubleshooting. FSTopo, measured on one sheet on 2026-10-01: 7.0 s to expand a 21.2 MB sheet and 3.6 s for overviews, 24.5 MB, about 1.2 times the download; QMapShack drawing FSTopo.vrt has not been measured either.
Keeping it current¶
- probe: none
- strategy: reinstall
- Follows usgs-ustopo: a new sheet is warped on the next install and the map is rebuilt when the set of sheets changes.
Where to get help with the software itself¶
The GDAL documentation (https://gdal.org/) for the tools; QMapShack's wiki (https://github.com/Maproom/qmapshack/wiki) for how it shows raster maps.