Advances in adaptive sampling science as applied to tropical cyclones indicate that additional observations in relatively small areas of the environment of the storms would improve track predictions. It is proposed that these targeted observations may be acquired by an Unmanned Aerial Vehicle (UAV) equipped with Global Positioning System (GPS) dropwindsondes that would be deployed from 35,000 feet in the sensitivity areas indicated by two adaptive sampling techniques. The specific proposal is to use the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Altus UAV for field experiments in the western North Pacific during 1999 and 2000. Feasible flight plans have been developed that would yield the targeted observations in the sensitive areas indicated by adaptive sampling. Seven science missions averaging 23 h in duration and deploying 35 to 40 dropwindsondes are planned during 1999, and ten missions of similar duration and dropwindsonde deployments are planned during 2000. The impact of the observations in the sensitivity area will be demonstrated after the field experiment with data-denial experiments using state-of-the-art numerical weather prediction models.
This presentation will describe the Altus UAV and its flight performance characteristics, the development and testing of the miniaturized HiMetSonde GPS dropwindsonde, and representative flight plans derived from adaptive sampling. Preliminary operation plans have been developed for aircraft staffing, science team staffing, and science mission flight operations during 1999 and 200l. Although these plans are ambitious and challenging, a great potential exists for contributing to improved tropical cyclone track prediction via adaptive sampling using UAVs. Accumulated over two field experiments, enough independent cases of track improvements and more accurate UAV life cycle costs will be gained for cost-benefit analysis.