<title>Wind scatterometry and the status of the NASA scatterometer</title>

Abstract

The NASA Scatterometer (NSCAT) was launched in August 1996 aboard the Japanese Advanced Earth Observation System-I (ADEOS-I) as part of the NASA Earth Probes program. NSCAT is an active microwave remote sensor designed to measure winds over the ocean from space. NSCAT can measure vector (speed and direction) winds over 90% of the Earth's ice-free oceans every two days. Such data is important in weather prediction and air-sea interaction studies since winds modulate all air-sea fluxes. The Ku-band NSCAT is a follow-on to the Seasat scatterometer but has improved resolution and coverage. NSCAT is a Doppler scatterometer with 600 km wide swaths on either side of the nadir track. In comparison the C-band ERS-1/2 Active Microwave Instrument scatterometer system has only a single swath. A follow-on to NSCAT, known as SeaWinds, is in development and will be launched in 1999. The on-orbit performance of NSCAT is superb with initial data products delivered to the science team within two months of the start of data collection. This paper provides a brief overview of the NSCAT mission and its status and briefly discusses the results of the calibration and validation study and some new applications of NSCAT data.