A new aerological sonde for dense meteorological soundings

A new recoverable aerological sonde has been developed for studying mesosca le atmospheric processes. It allows for precise temperature, humidity, pres sure, and wind measurements with (i) high spatial resolution (e.g., up to 1 00 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 microcontroll er 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 mob ile telephone for sonde recovery. Accurate offline differential GPS (DGPS) wind solutions are obtained by simultaneous GPS reception of a stationary r eceiver. Optionally, DGPS-based wind data may be obtained by reception of G PS 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. Arbitraril y, many sondes (typically 30 sondes) can be operated simultaneously and no ground-based or aircraft-based station is required for this purpose. Extens ive tests of the dropsonde version have proved the reliability of the entir e system and the acquired data. Due to the high probability of recovery, th e possibility of multiple use without calibration or major refurbishment, a nd the optional extension by other sensors, the system is considered an alt ernative to standard sondes applied for research purposes.