User manual VAISALA RD94 DATASHEET

[. . . ] www. vaisala. com Vaisala Dropsonde RD94 and the Vaisala RS92 radiosonde family. The winds are measured using a commercial GPS receiver, which has a custom made firmware to ensure proper wind measurement. [. . . ] The delayed deployment mechanism ensures proper clearance from the aircraft, and allows the parachute to open safely. The specially designed parachute stabilizes the RD94 aligning it properly for measurements, and its small gliding factor ensures proper measurement of the wind speed and direction. The descent speed of the RD94 is approximately 11 m/s at the sea level, and about 21 m/s at a 12 km altitude. In strong convective situations the descent rate can vary a lot, and even negative (descent) rates are measured. The RD94 measures the PTU twice and wind speed and direction four times a second. the last measured pressure level is at maximum about 5 - 6 meters above the surface. The robust design of the RD94 ensures safe use of the legacy launchers and high speed deployment of the parachute. Intellectual Property Rights and Development Vaisala Inc. , USA, manufactures and markets the Dropsonde RD94 and AVAPS Dropsonde Receiving System under license to University Corporation for Atmospheric Research Foundation (UCARF). The dropsonde and receiving system hardware and software have been developed at the Earth Observing Laboratory (EOL) of the National Center of Atmospheric Research (NCAR), in Boulder, Colorado, USA. The Vaisala Dropsonde RD94 is a meteorological measurement device to be used in atmospheric profilings from aircraft flight level to surface. Descending through the atmosphere by a parachute, it measures the profiles of pressure (P), temperature (T), relative humidity (U) and wind direction and speed from the point of launch to the ground. The RD94 transmits data using a narrow bandwidth FSK (Frequency Shift Key) modulation in the 403 MHz meteorological band to the AVAPS (Airborne Vertical Atmospheric Profiling System) onboard the aircraft. Vaisala Dropsonde References Since 1996, about 50, 000 earlier versions of the Vaisala Dropsonde RD93, have been used in eight countries by various operators. [. . . ] The reproduction, transfer, distribution or storage of information contained in this brochure in any form without the prior written consent of Vaisala is strictly prohibited. All specifications -- technical included -- are subject to change without notice. [. . . ]