A new class of robotic aircraft are being developed to carry a suite of sensors to collect meteorological data in remote areas of the Earth. These aircraft are capable of flying at altitudes above 18 km and remaining aloft for over 12 hours. They are seen as a complement to existing manned aircraft and satellites now used to collect meteorological data. These aircraft place no human crew at risk and will be less expensive to operate compared to traditional manned aircraft. However, the near-term robotic aircraft have limited payload capacity so lightweight sensors must be selected. Also, airspace operations must be planned so that they will not interfere with other air traffic or place people or property at risk on the ground or at sea.
NASA’s Environmental Research Aircraft and Sensor Technology (ERAST) program is sponsoring development of several aircraft which could be used in a series of missions to demonstrate how meteorological data can be collected and delivered to improve weather forecasts and improve scientific modeling of the global climate. Descriptions of these aircraft and their enabling technologies are provided.
To perform meteorological missions, these aircraft will carry dropwindsondes. NASA is co-sponsoring an effort to modify an existing sonde to be used on high altitude aircraft. A description of these sensors is provided. A satellite communications system is being used to control the aircraft and send some data back in real time. This communications system is also described.
The planned demonstrations are described. Initial emphasis of the NASA demonstrations is to collect data on tropical cyclones far from land—beyond the range of current manned aircraft. Initial demonstrations will use dropwindsondes to gather data. An adaptive sampling experiment proposed to demonstrate improved track forecasting in the Pacific is highlighted. Subsequent demonstrations will gather data to improve cyclone intensity prediction and to study cyclogenesis.
Future systems are also presented. For cyclone observations, plans are to make use of airborne expendable bathythermographs (AXBTs) as an additional aid in understanding cyclone intensity, based on ocean temperatures. The possibility of larger aircraft that can carry Doppler radars is also discussed. These radar-equipped aircraft could be used to observe windfields, such as cyclones during landfall or supercell formation over land.