Three rasters have arrived for the London green-infrastructure work — an elevation model, a land-cover map and a Sentinel-2 clip — and the data manager will not release them to the analysts until they have been checked. The acceptance form asks for a handful of measured facts per file, so that a later dispute about a result can start from what was actually delivered.
Report, from the files as delivered:
dem_valid_pixels — DEM pixels that are not nodatadem_min_m, dem_max_m — the DEM's minimum and maximum valid values, two decimalsdem_pixels_below_zero — DEM pixels with a valid value below 0 mlandcover_nodata_pixels — land-cover pixels equal to 0sentinel_epsg — the EPSG code of the Sentinel-2 clip's CRSRead the numbers from the full-resolution data, not from a viewer's statistics panel: a viewer computes its min and max from an overview, and the acceptance form is about the file.
These are where the teaching is. Read them twice.
A raster acceptance form — extent, nodata, range, CRS, measured not assumed — is what lets a team say later which delivered file a result came from.
Work the problem in whatever tool you like, then enter the answers here.
dem_valid_pixelsdem_min_mdem_max_mdem_pixels_below_zerolandcover_nodata_pixelssentinel_epsg6 scored, 0 informational
DEM valid pixel count
18%DEM minimum
18%DEM maximum
18%DEM pixels below zero
18%Land-cover nodata pixels
9%Sentinel-2 CRS
18%