Alfred-Jose
New member
I am attempting to ingest a custom high-resolution SRTM dataset into WPS (Geogrid). I have successfully converted the GeoTIFFs to the WPS binary format and updated GEOGRID.TBL and index, but the resulting geo_em.d0X.nc topography field (HGT_M) is entirely zeros.
Diagnostics performed:
Diagnostics performed:
- Binary Validity: Verified. I reverse-engineered one of the generated binary tiles back to GeoTIFF; the data is valid (signed int16, elevation ~2600m). od -t d2 confirms non-zero integer values in the files.
- Naming Convention: Files are tiled and named xxxxx-XXXXX.yyyyy-YYYYY (e.g., 32001-34000.27450-29449).
- Metadata: index file specifies projection = regular_ll, row_order = bottom_top, and known_lat/known_lon correspond to the bottom-left corner of the full dataset.
- TBL/Namelist: GEOGRID.TBL rel_path is confirmed correct. geogrid.log shows "Processing data source..." followed by "Computed", indicating the files are found but interpolation yields zeros.
- Source: SRTM (Lat/Lon), dx/dy ~ 0.000808 deg.
- Domain: Mercator, centered at 33.3N, 77.1E (Ladakh region).
- Index Params: known_x=1, known_y=1, known_lat=14.99, wordsize=2, signed=yes.
Since the binary data is valid and covers the domain area, why would Geogrid fail to map it? Is there a known issue with regular_ll indexing precision or known_lat definition (pixel center vs. corner) that could cause a total shift?