High resolution elevation data derived from stereoscopic CORONA imagery with minimal ground control : an approach using IKONOS and SRTM data

摘要

The first space mission to provide stereoscopic imageryudof the Earth’s surface was from the American CORONAudspy satellite program from which it is possible to generateudDigital Elevation Models (DEMs). CORONA imagery andudderived DEMs are of most value in areas where conventionaludtopographic maps are of poor quality, but the problem hasudbeen that until recently, it was difficult to assess theirudaccuracy. This paper presents a methodology to create audhigh quality DEM from CORONA imagery using horizontaludground control derived from Ikonos space imagery andudvertical ground control from map-based contour lines. SuchudDEMs can be produced without the need for field-basedudground control measurements which is an advantage inudmany parts of world where ground surveying is difficult.udKnowledge of CORONA image distortions, satellite geometry,udground resolution, and film scanning are important factorsudthat can affect the DEM extraction process. A study areaudin Syria is used to demonstrate the method, and ShuttleudRadar Topography Mission (SRTM) data is used to performudquantitative and qualitative accuracy assessment of theudautomatically extracted DEM. The SRTM data has enormousudimportance for validating the quality of CORONA DEMs, andudso, unlocking the potential of a largely untapped part ofudthe archive. We conclude that CORONA data can produceudunbiased, high-resolution DEM data which may be valuableudfor researchers working in countries where topographic dataudis difficult to obtain.