Defence research organisation DRDO has indigenously developed Aerostat radar which will help strengthen the air defence network of the armed forces. AIR correspondent reports, the Aerostat radar developed by DRDO's Agra-based Aerial Delivery Research and Development Establishment laboratory will boost the country's surveillance capabilities. It is undergoing final trials with full payload and is expected to be delivered to the armed forces in the near future.The Aerostat radars, which basically include sensors mounted on blimp-like large balloons tethered to the ground with long cables, are a long-standing requirement of the air force.The DRDO-made aerostat radar has been designed to rise one kilometer above the ground and its payload includes electro-optical sensors and equipment for communication intelligence.