1965 (KH-4B) Corona image of river Ganga adjoining Varanasi showing three areas with well defined changes in r... Read More

NEW DELHI: Indian scientists are using declassified satellite images of US military intelligence to “reconstruct the river Ganga of the past”. The images were originally used for reconnaissance and to produce maps for the American intelligence agencies including CIA.

The classified military satellite system (code-named CORONA) had acquired photographic images of the entire Ganga river basin during 1960s.

“Idea of this exercise is to establish reference condition of the Ganga river and quantify the changes in morphological characteristics and land-use/land-cover within the Ganga valley between 1960s and present. The move will help in framing policy for ‘desirable’ land-use within the entire river basin,” said Rajiv Ranjan Mishra, director general of the National Mission for Clean Ganga (NMCG).

The task to reconstruct the Ganga river basin of the past ‘from Corona archival imagery’ has been given by the ministry of earth sciences to IIT, Kanpur.

Mishra told TOI the reconstruction would help us understand the extent of encroachment and siltation over the years. “We will use the imagery to formulate the best practices, taking lessons from the past about natural course of the flow. It’ll help us in our ongoing efforts at multiple levels to rejuvenate the river and ensure its ecological flow”, he said.

Deliverables of project will be to make all processed Corona images available for upload on public portal such as the ISRO-backed Bhuvan geo-portal and develop an Atlas of the Ganga river showing a comparison between 1960s and the present.

According to information available on website of the United States Geological Survey (USGS), the first generation of the US photo intelligence satellites collected more than 8,60,000 images of the Earth’s surface between 1960 and 1972. The classified military satellite systems acquired photographic images from space and returned the film to Earth for processing and analysis. The images were declassified in 1995.

“The first successful CORONA mission was launched from Vandenberg Air Force Base in 1960. The satellite acquired photographs with a telescopic camera system and loaded the exposed film into recovery capsules. The capsules or buckets were de-orbited and retrieved by aircraft while the capsules parachuted to earth. The exposed film was developed and the images were analyzed for a range of military applications,” said the USGS on its website.

The NMCG - a nodal authority to implement and monitor the centre’s ongoing ‘Namami Gange’ (Ganga rejuvenation) programme - has already been using GIS technology to get minute details of the river basin for its decision-making processes. Besides, the Survey of India has been using Drones and vehicles with cameras to captured 360 degree panoramic views of the Kumb Mela areas in Uttar Pradesh. The move has helped in identifying polluted drains joining the river Ganga.

