Abstract: A radiosonde for measuring atmospheric parameters, such as pressure, temperature, and humidity, includes a microprocessor interfaced with an analog-to-digital converter, which, in turn, receives sequential input signals representing the sensed atmospheric parameters, and converts those signals to corresponding digital data. This digital data is processed in the microprocessor, and applied as a digital data stream to an RF transmitter from where the data is transmitted to a remote ground processing station. A flap member on the radiosonde housing, which is movable between an open and a closed position in response to air flow, cooperates with a switch to provide a signal to the microprocessor indicating the launch and descent of the radiosonde. A preset input to the microprocessor is provided to automatically terminate transmission of meteorological data when the radiosonde has reached a predetermined altitude.

Abstract: A housing for electrical components and equipment sent aloft with a weather balloon to measure atmospheric parameters comprises a light-weight polystyrene case that serves as a shipping container and flight package. The housing also includes an air duct and a humidity sensor in the duct. Means in the duct minimize the reflection of sunlight onto the sensor to maintain at ambient temperature the air which flows over a humidity sensor.

Abstract: A pressure transducer such as for use in a radiosonde includes a substrate and a plurality of conductive contacts formed thereon. An arm is movable over the contacts in accordance with the sensed ambient pressure. A group of resistors of different values of resistance are operatively connected to the contacts whereby each contact is characterized by a unique value of resistance. The resistance may be connected as the frequency-determining element of an oscillator, such that each unique value of resistance may be converted to a unique corresponding frequency and upon decoding determine which unique contact is operatively connected.