THE ELDORA ASTRAIA AIRBORNE DOPPLER WEATHER RADAR - GOALS, DESIGN, AND FIRST FIELD-TESTS/

This paper describes the development and first operation of an innovat ive research tool for observing atmospheric storms: art airborne X-ban d Doppler radar. The radar has been built jointly by the National Cent er Sor Atmospheric Research (NCAR) in Boulder, CO and the Centre de Re cherche en Physique de l'Environnement Terrestre et Planetaire (CRPE) in Paris, France. The radar is called ELDORA/ASTRAIA for Electra Doppl er Radar/Analyse Stereoscopic par Radar Aeroporte sur Electra. The rad ar is designed to provide high-resolution measurements of the air moti on and rainfall characteristics of very large storms. storms which are frequently too large and/or too I-emote to be adequately observed by ground-based radars. This paper includes discussions of the scientific impetus and design criteria, as well as the engineering solutions to these design needs. The design options and tradeoffs and the resulting capabilities are discussed. The paper concludes with an evaluation of the performance of the system at its first field lest, conducted as a part of the international global warming experiment in the equatorial Pacific Ocean known as the Tropical Ocean Global Atmosphere Coupled O cean-Atmosphere Response Experiment (TOGA COARE). This evaluation illu strates that the major design goals for the radar-collection of relati vely noise-free velocity and reflectivity data using a rapid scanning radar-have been adequately met. Future options for further improvement s to the radar are discussed.