Test Location: Morro Bay, CA (35.3°N, -120.8°W)
Request: res_m=1 (1 meter resolution)
Result: ✅ Successfully downloaded 1m resolution GeoTIFF
- Dimensions: 1,872 × 2,262 pixels
- Pixel Size: 1.00m × 1.00m (exactly 1 meter)
- Coverage: ~1,872m × 2,262m area
- File Size: 13.2 MB
- Data Source: USGS 3DEP 1m (confirmed from point query)
- Format: Cloud-optimized GeoTIFF
- Morro Bay, CA:
us_3dep_1m(1m resolution) ✅ - Germany:
germany_bayern_1m_dtm(1m resolution) ✅ - Norway:
norway_10m(10m resolution) - Australia:
copernicus_30m(30m resolution)
- Up to 0.5m (50cm) in areas with lidar data
- 1m in areas with USGS 3DEP coverage (USA)
- 10m in some countries (Norway, etc.)
- 30m global fallback (Copernicus DEM)
- USA: 1m (USGS 3DEP) - highest quality
- Some European countries: 1m (country-specific lidar)
- Global: 30m (Copernicus DEM) - fallback
- Minimum
res_m: 1m (can request finer, but may not have data) - Maximum
res_m: 30m (cannot request coarser) - Best practice: Request 1m-30m based on area coverage
GPXZ DOES provide 1m resolution data where available:
- ✅ Verified with actual raster download
- ✅ Pixel size confirmed: exactly 1.00m × 1.00m
- ✅ Uses USGS 3DEP 1m for USA regions
- ✅ Can go as fine as 0.5m in lidar-covered areas
However:
- Resolution varies by location (not all areas have 1m)
- Falls back to 30m globally (Copernicus)
- Cannot request >30m (no support for 250m/500m/1000m)
GPXZ is excellent for:
- High-resolution regions (1m-30m)
- USA regions (1m USGS 3DEP)
- Small, detailed areas
- When better quality than OpenTopography needed
GPXZ is NOT suitable for:
- Coarse resolutions (>100m)
- Large regions needing 250m/500m/1000m
- When OpenTopography 30m/90m is sufficient