Cartosat-1 hails Earth

on Sunday. "Regular operational fine tuning," was on, he said, which will take between a month and six weeks.

The spacecraft, being tracked by ISRO Telemetry, Tracking and Command Network, a facility here that monitors ISRO's remote sensing spacecraft, will be operational in six weeks. It will then start sending data to another ISRO facility, the National Remote Sensing Agency in Hyderabad, he said.

Two panchromatic cameras on board the spacecraft, which can pick up objects only 2.5 metre across, have started sending encoded signals.

As the satellite's name suggests, the data will be used to build accurate maps of the swaths of land the cameras can photograph.

The Rs 250 crore, 1.56 tonne spacecraft has been placed in a sun-synchronous polar orbit of 618 km by an indigenous Polar Satellite Launch Vehicle, the PSLV-C6, and goes round the Earth every 97 minutes, revisiting a given spot every five days.

Antrix, the department of space's commercial arm, sells data from the remote sensing satellites in Europe, Russia, the Americas and China, ISRO officials said.