Abstract

A new recoverable aerological sonde has been developed for studying mesoscale atmospheric processes. It allows for precise temperature, humidity, pressure, and wind measurements with (i) high spatial resolution (e.g., up to 100 m) as a parachute dropsonde version and (ii) high temporal resolution as balloon sonde version. The sonde comprises sensor elements of a commercial radiosonde, a 12-channel GPS receiver, a mobile telephone, a microcontroller as a central processing unit, a 4-Mbyte flash memory, a power pack, and a UHF transmitter. Data are stored internally and no data telemetry is used except for GPS data of the landing location, which are transmitted via mobile telephone for sonde recovery. Accurate offline differential GPS (DGPS) wind solutions are obtained by simultaneous GPS reception of a stationary receiver. Optionally, DGPS-based wind data may be obtained by reception of GPS corrections transmitted via VHF or satellite. After removal of selective availability from GPS signals in May 2000, winds based on GPS stand-alone solutions only are found to be of similar quality as DGPS winds. Arbitrarily, many sondes (typically 30 sondes) can be operated simultaneously and no ground-based or aircraft-based station is required for this purpose. Extensive tests of the dropsonde version have proved the reliability of the entire system and the acquired data. Due to the high probability of recovery, the possibility of multiple use without calibration or major refurbishment, and the optional extension by other sensors, the system is considered an alternative to standard sondes applied for research purposes.