 ORTHOPHOTO PREPARATION
Source:Scanned images
Satellite images of adjacent land areas (Scale: 1:30,000) were merged, grey scale adjusted and different land cover types were classified. AABSyS created an ortho-photo (composite image) from four satellite images (in TIFF format). The four images were merged with a minimum loss of contrast, the grey scale was adjusted and minor mismatched at the edges were fine-tuned. The same gray scale was maintained across the composite image so that different land types such as forest, agriculture, urban are easily distinguishable. Different land cover types were classified such as forests, urban and rural settlements, highways, main roads, side roads, buildings, rivers, trenches, railway tracks, TV towers, windmills, electric lines, trees, parks, fields, cultivated lands. Different land classifications were shown as area objects in different polygons. The work was performed using ERDAS Imagery software. The ortho-photo image was delivered in TIFF format, and the vectorized land classification file was delivered in Arcview SHP format and AutoCAD DXF format. |
