High Resolution 1:10,000 scale Mapping Strategy of Multi ... - NDMA

cent of the country is covered. The condition of the air photos/PT sections
may not be appropriate to undertake mapping at 1:10,000 scale
topographical mapping. The search for such items and then to scan it for
Digital Elevation Model (DEM) generation will take a long time. In some
places, fresh photography will become necessary considering the (a) scale
of photography, (b) condition of photography, and (c) location of such
materials.
Further, with the PT sections which have to be scanned can only generate
contour interval (CI) of 5m while 2.5m CI can be extrapolated. The general
requirement is of 2m CI with extrapolation of 1m. Hence, there will be a
limitation if we use PT section developed earlier for 1:25,000 scale
topographical maps.
3. The third option is of using remote sensing satellite data having stereo
capabilities, i.e. which can generate height or CI at 2m/1m. The Indian
satellite Cartosat 1 which has the stereo capability is not good enough to
provide such CI. Hence we have to consider other options. Here we have
following two options :
(a) WorldView Stereo product by M/s Digital Globe having resolution of
0.5m.
(b) GeoEye stereo products by M/S GeoEye again having a resolution
of 0.5m.
Both the above satellites are US based and are willing to provide data as per
the US regulation, i.e. at 0.5m resolution. WorldView stereo data is available while
the former satellite has just then launched and the first product was to be made
available from November 2008 onwards. Further, considering the WorldView data
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