The role of satellite derived maps in National Spatial Data Infrastructure

PVSP.Prasada Raju Sujata Ghosh and J. Saibaba
ADRIN, Dept.of.Space, Govt.of.India
203, Akbar Road, Tarbund Secunderabad-500 009


Abstract
A vista of satellites comprising, Indian Remote Sensing (IRS) series and other satellites launched by Space Imaging, European Space Agency, Earth watch, Radarsat etc, will provide remotely sensed data in Multi-spectral, Multi-resolution and Multi-sensor on a repetitive basis. Data from various satellites will cater the requirements of decision makers at regional to Micro (Village) level. In fact, the Dept.of.Space has carried out many Remote-sensing application projects at the country, regional and local scales using multi-resolution imagery. These projects proved the capability of remotely sensed data in natural resources mapping. The latest technological developments in the fields of Remote sensing, Geographic Information system (GIS), and Global positioning Systems (GPS) offering a wide variety of tools for integration, conversion and manipulation of data (with heterogeneous nature) into flexible, efficient and precise spatial databases. The geospatial database (information) available at the National Spatial Data Infrastructure (NSDI) will be used in a wide range of applications through a centralized database at various government organizations, public undertakings and Non-governmental organizations. The database available at the NSDI has to cater the data requirements at least three levels, namely, National, Regional and Local scales. Data in the form of small-scale maps already available with many organizations like Survey of India, Geological Survey of India, National Atlas and Thematic Map organization etc. The premier institute, Survey of India (SOI) has been preparing and supplying topographic maps for the country on 1:250, 000, 1:50, 000 and 1:25, 000 scales and moreover many of these maps are few decades old. In the context of NSDI, it is pertinent here, describe the capability of remote sensing technology visa-vis map requirements and availability of maps in the country.

It will be appropriate here to discuss the technical lag between the large-scale topographic maps on 1:25,000 scale published by SOI and the utilization of information provided by finer resolution (around 1 meter) offered by recently launched satellites. The utility of remotely sensed derived information/maps, especially from finer resolution satellites was described in the context of National Spatial Data Infrastructure.