Entrepreneurs at ESA’s Business Incubation centre in the Netherlands have used radar technology from the agency’s Envisat remote-sensing satellite to develop a compact, high-resolution radar that can monitor land and buildings from small aircraft. The radar can monitor structures such as dams, harbours, canals and buildings, leading to maps for urban planning, territory surveillance and cadastral updating. Several flights over the same location can spot changes between pictures, revealing ground movements that could affect structures. The sensor’s main advantage is that it can be flown on small, readily available and inexpensive aircraft. In comparison, conventional bulky radar requires large, costly planes, while laser systems need more time to take high-resolution pictures, and are therefore often flown on costly helicopters.

Source : http://www.esa.int