A to Z GIS | Explore this related guide, featuring updated terms and graphics and developed in coordination with Esri’s GIS Dictionary team.
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[photogrammetry]
In raster data, a unitless digital value of a pixel, sometimes called a density number (DN), representing a measurement of light, intensity, energy, elevation, temperature, or another physical characteristic of an object. This is a relative value subject to sensor sensitivity, bit depth, and material properties of the object captured.