New Delhi, Aug 9 - The Indian Space Research Organisation (ISRO) is developing a constellation of seven satellites to give a boost to the country's security apparatus, a top scientist said here Sunday.

ISRO chief G. Madhavan Nair said the Indian Regional Navigational Satellite System (IRNSS) was being developed 'considering security related issues'.

Speaking at the Indian Institute of Technology-Delhi, Nair said: 'The proposed system would consist of a constellation of seven satellites and a ground support segment. Three of the satellites will be placed in the geostationary orbit and four near the geostationary orbit.

'Such an arrangement would mean all seven satellites would have continuous radio visibility with the Indian control stations.