Field testing of recoverable sounding systems in South Africa.


Fig 01: Position of powersonde every second during its last flight, based on ~33 minutes of telemetry data. Maximum distance away from the home point (center of plot) was less than 1 km.


Fig 02: Plot of height versus time for the last flight (until telemetry ended). The Powersonde actually reached 6000 feet above ground level (AGL), but data have been shifted downward to correct for low offset in data reported from a pressure sensor below 3000 ft (rather than GPS altitude). Vertical lines are every minute


Fig 03: Plot of powersonde position based on data from third ascent during last flight. Note than maximum offset from home point is less than 300 m.


Fig. 04: Altitude versus time plots for the four ascents during the last flight of the powersonde. Vertical lines are every minute.


Fig. 05: Groundspeed from the GPS position information during the first ascent of the last powersonde flight. The linear fit shows the increase in flight speed with height/time as the powersonde ascended. Vertical lines are every minute.


Fig 06: Same as figure 05 except for the third ascent. Both figures suggest that the powersonde can fly at ~27 m/s (~52 knots) at ~11,000 feet above sea level (ASL). Vertical lines are every minute.


Fig 07: Temperature, pressure and Relative humidity traces from a RS-80 radiosonde on the powersonde from a flight on February 20th 2002. The powersonde cycled between the surface/500 ft and 6000 ft AGL twice during this flight.


Fig 08: A plot of temperature versus pressure obtained during the two ascents and two descents on February 20th. There is a ~2 °C offset between the ascending and descending flight temperatures; the cause is unknown and is being investigated.