An aerial view of Guwahati. File picture

April 17: The Assam-Nagaland Geospatial Data Centre under the Survey of India has chalked out a Rs 1.4-crore plan for aerial mapping of the city.

Acting upon a request from the state’s Directorate of Land Records, the centre prepared a plan for the 300 square km expanse of the city and its suburbs to be aerially photographed. The project — a first for the state — will be executed either by the ministry of defence or the National Remote Sensing Agency.

“We will start the job as and when the government approves the plan. After getting clearance, we will approach the surveyor general of India, Dehradun, for permission to go ahead,” said P.K. Ganguly, the director of the centre.

Ganguly said the surveyor general’s office would subsequently get in touch either with the ministry of defence or with the National Remote Sensing Agency to execute the plan.

Survey of India will provide baseline information for the mapping project, which is expected to take a couple of days. After the photography is completed, Survey of India will scan the information and begin work on drafting the map.

A flight plan will be prepared by the authorities on the aerial route to be taken.

“There are mainly two criteria which are taken into consideration before undertaking aerial photography — the cloud cover should be thin and the atmosphere should be clear,” Ganguly said.

Dispur has also asked the centre to prepare a digital terrain model of the city. A digital map of the city showing almost every structure on the land surface, including the road and sewerage network, has already been prepared by the data centre.

Ganguly said the map would be released to the public after getting the necessary clearance. “The map will come in very handy while planning development projects as it will provide images of every possible structure,” he said.

“The best thing about the digital map is that information can be updated on any new structure which needs to incorporated,” he said.

A marketing division has been opened at the centre’s office to help market the map to civic agencies in need of such documents.

Survey of India is the national survey and mapping organisation of the country under the department of science and technology. It is the principal mapping agency, whose main task is to ensure that the country’s domain is explored and documented suitably through base maps.