Abstract

 

           A map scale of 1:25,000 satisfies the needs for a wide range of map users including urban city planners, as well as several GIS applications. Nowadays because of high potential of satellite images, maps production procedure and their updating increasingly go towards using satellite photogrammetry. The advantages of using satellite images show the necessity of more evaluation and studying on satellite images more than ever. This study includes a comprehensive comparison of geometric accuracy and information content between two most commonly used imageries, IRS-P5 and ALOS-PRISM for updating of 1:25,000 -scale maps. Information content of imageries was evaluated based on object identification and extraction for all features of 1:25,000- scale maps. Accuracy in the vertical direction was calculated by comparing the spot height values of more than 170 points with elevation values measured on aerial photographs. More than 150 points extracted from planimetric features were used for accuracy assessment in planimetric direction. The results of these evaluations show that IRS-P5 stereo images, from the point of geometric accuracy, have the capability of 1:25,000- scale maps revision, also, from the point of information content, have the capability of revision for most objects in 1:25,000- scale maps. The planimetric accuracy of ALOS-PRISM satisfies needed accuracy for 1:25,000- scale maps, but some block noises that adversely affect the legibility of image, reduce the altimetric accuracy. Values of accuracy statistics show that ALOS-PRISM stereo images are not suitable to acquire heights of features by stereo plotting.

 

Summary: a comprehensive comparison of geometric accuracy and information content between IRS-P5 and ALOS-PRISM for updating of 1:25,000 -scale maps

 

Abstract: IRS-P5 imageries are more suitable than ALOS-PRISM for updating of 1:25,000 - scale maps because of more reliable altimetric accuracy and better information content.

 

What attendees will learn: more information about orientation, stereo mapping, accuracy assessment and other specifications of ALOS-PRISM and IRS-P5 imageries