Function lupnt::LoadLolaDem

Function Documentation

LunarDem lupnt::LoadLolaDem(double lat_deg, double lon_deg, double half_width_m = 5000.0, double max_res = 20.0, const std::filesystem::path &dem_file = {})

Load the appropriate PGDA product-78 DEM for a query latitude/longitude.

Selects the nearest site (SelectLolaSite), ensures its GeoTIFF is downloaded/cached (DownloadLolaDem), then crops a 2*half_width_m square window centered on the tile and downsamples it to at most max_res grid spacing via the existing LoadTiff.

When dem_file is non-empty it overrides the site download entirely: the given GeoTIFF is loaded/cropped/downsampled directly (no DownloadLolaDem, no network access). The site metadata attached to the returned LunarDem is still the nearest SelectLolaSite entry for the query lat/lon (a synthetic label, since the explicit file may be any tile). This is the path used to run surface scenarios against a small bundled fixture tile.

Parameters:

  • lat_deg – Query latitude [deg] (negative near the south pole).

  • lon_deg – Query east longitude [deg].

  • half_width_m – Half-width of the square crop window [m] about the tile center.

  • max_res – Maximum output grid spacing [m] (downsampling target).

  • dem_file – Optional explicit GeoTIFF path; if set, skips site select/download.

Returns:

The cropped/downsampled LunarDem.