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November 2002 |
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GPS-Security and Restriction
Restriction Policy
Nobody is fully aware as to what in fact is the Restriction Policy of the Government of India as no such consolidated document is available. If such a document is made available it will end all confusion. It is expected that the Government will soon come out with a comprehensive Restriction Policy document in respect of Geo-spatial data capture and distribution, and make it known to the public so that it follows the law of the land that is just and rational and works in the best interests of the country. Restrictions on geo-spatial data are being notified in piecemeal manner through departmental circulars and orders, which are unclear and incomplete. The following is the summary of various restrictions, as the author understands them:
- Topographical Maps: All topographical and geographical maps a) of areas between a line approximately 50 km from external boundary of India and the external boundary on scales 1: 1 million and larger north of 200 latitude; b) areas between a line approximately 50 km from Indian coast-line and the Indian coast-line south of 200 latitude and c) of outlying islands viz. Andaman and Nicobar, Lakshadweep, Minicoy and Amindivi on scales 1:1 million and larger are all restricted. All maps inside of these lines are unrestricted.
- Position data in latitude and longitude: Horizontal control data up to 1 minute of arc of latitude or longitude are restricted. It appears that in a subsequent order it was mentioned that better data can be given without any restriction but meaning of this has not been clear. Do we conclude that data even up to second place of decimal can be made available? This is open to scrutiny and should be clarified. The authorities may be able to explain this.
- Heights: Heights above mean sea level rounded off to 10 metres in restricted zone, and rounded off to 10 cm in unrestricted zone are not restricted. All others are restricted.
- Aerial Photographs: All aerial photographs are classified as secret unless advised to be graded top secret by the Air Headquarters, Air Force. It is learnt that some photographs as decided by the authorities are made available for educational purposes on payment by requesting Director Survey Air of Survey of India New Delhi.
- Export of Maps: Even unrestricted Survey of India maps of scales even smaller than 1:250,000 should not be exported.
- Satellite Imageries: All Satellite imageries of 10 metres and better resolution are restricted.
- Gravity Data: There are restrictions on gravity and magnetic data also. It is not clear as to what extent gravity values and gravity anomalies are restricted. Similar is the case with magnetic data. These will have to be ascertained by the authorities.
- Indian Grid Data and Maps with Indian Grid: Indian Grid is on Lambert Conformal Conic Projection. India is divided into 9 zones. These grids are superimposed on topographical maps which are in so called Polyconic Projection. Once this grid is superimposed on any map even of unrestricted area, the map is classified as restricted. All parameters and all data in rectangular coordinates (x, y or Easting, Northing) pertaining to these grids are restricted.
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