Abstract

LARGE SCA LE DIGITAL TOPOGRAPHIC DATABASE FOR SUSTAINABLE PLANNING & SC IENTIFIC DESIGN OF COAL MINING
The map data in the form of computer readable file/(s) is referred to as Topographical Data Base and its scale in expressed by a representative factor ( viz. 1:10K). Topographical Data Bases are described either Small Scale or Large scale. CMPDI felt the need of Large scale GIS ready Digital Topographic Data and thus approached Survey of India , the national surveying & mapping organisation for preparing map of around 27 coalfields spanning over 7 states of India. Aerial Photographs on 1:15,000 scale of 0.3 metres ground resolution were used as input for coalfields of larger pockets and World View Stereo Imagery of spatial resolution 0.46m and 11 bit radiometric resolution for coalfields of smaller pockets. The output is the Topographical map sheets in UTM projection, WGS-84 datum & heights above Mean Sea Level both in digital and hard copy formats. Photogrammetric technique using Aerial photo/ Imagery were adopted to create the orthophotos for 2D feature extraction.3D features also were extracted from stereo models of high hill region in order to achieve required accuracy. The contours were digitally generated using corrected/edited DTM, orthomorphic features & ground height etc. as the input.