This multitemporal radar image, acquired by Envisat's Advanced Synthetic Aperture Radar (ASAR) instrument, is composed of two images - one acquired on 26 July 2007 and another on 12 April 2007 - and highlights the flooding in Bangladesh and parts of India brought on by two weeks of persistent rain.
ASAR is able to peer through clouds, rain or local darkness, and is well suited for differentiating between waterlogged and dry land. Areas in black and white denote no change, while areas outlined in blue are potentially flooded spots. Areas in red may also indicate flooding, but could also be related to agricultural practices.
The bright white area on the bottom left of the image is Calcutta, and Dhaka, the capital of Bangladesh, is visible as the bright white area in the centre right. The mouth of the Ganges is visible in the centre, and the Brahmaputra River is seen (blackish colour) splitting into two branches.