A high resolution scatterometer for radar backscatter measurements of wind generated waves in wind/wave tanks

In February 1988, combined measurements of microwave backscatter, wind, waves and gas exchange have been carried out in the large Delft Hydraulics wind/wave tank, with wind generated waves. In March 1989 a second exaperiment took place in the huge outdoor wave tank, the Delta tank, with wind generated waves and mechanically generated waves. These experiments were perfonned in the framework of the VIERS-1 project. In this project a number of Dutch and German institutes cooperate. Main objective is to increase the knowledge about the physics involved in the interaction of microwaves and the ocean surface and, from that point, to an improvement of the algorithms used for determination of wind speed and direction from satelliteborne microwave scatterometers. A second objective is to study the relation between the gas exchange at the water surface and the microwave backscatter. To achieve these objectives two wind/wave tank experiments and one ocean based platform experiment are scheduled. In this paper, the VIERS-l program will be outlined. The features of a specially designed high resolution scatterometer will be described and some results of both tank expermnents will be shown.