High-Precision Measurement of Height Differences from Shadows in Non-Stereo Imagery: New Methodology and Accuracy Assessment

The shadow-height method has been extensively used to extract the heights of buildings from shadows they cast in non-stereo (single view) aerial and satellite imagery. However, use this Earth sciences limited, partially due relatively low accuracy reported, fuzziness shadow edges, complexities scanning sensors, a lack software tools. In paper, we present an enhanced methodology offering significant improvement. These improvements are mainly result using physical approach model illumination gradient through edge by leveraging meteorological data precisely estimate atmospheric refraction. We validated 91 shadow-derived height estimations images obtained Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) at three sites with latitudes between 33 78°S: Andes Mountains, Sentinel Range, Abbot ice shelf. Reference measurements were Global Navigation Satellite System (GNSS) surveys Ice, Cloud, land Elevation (ICESat). observed errors fell below 6% for small differences (∼20 m) 2% larger (≳300 m). Our validation cover solar elevations ranging 3.7 42.2°, smaller absolute lower elevations. This novel information can be valuable studying surface elevation changes old imagery extending glacier volume variation time-series.