Chennai, May 21 (IANS) The countdown for the Wednesday launch of India's Polar Satellite Launch Vehicle (PSLV) carrying the radar imaging earth observation satellite, RISAT-2B began on Tuesday, said an ISRO official.

According to the Indian Space Research Organisation (ISRO) official, the 25-hour countdown for the PSLV launch started at 4.30 a.m. on Tuesday.

The PSLV-C46 as per ISRO's numbering system, will lift-off from the first launch pad at the rocket port in Sriharikota, Andhra Pradesh at about 5.30 a.m. on Wednesday.

The rocket will carry the RISAT-2B weighing 615 kg which will beef up India's surveillance capabilities from the sky.

India also plans to launch another radar imaging satellite named RISAT-2BR later this year.

According to the ISRO, the RISAT-2B satellite will be used for agriculture, forestry and disaster management.

About 15 minutes into its flight, the rocket will place the RISAT-2B into an orbit of about 555 km.

The PSLV rocket, that will fly on Wednesday, is the core alone variant without the strap on motors.

--IANS vj/ksk