Abstract: A relative humidity sensor includes a printed circuit board having a central passageway therethrough and a dielectric film extending across the passageway with electrodes mounted on that portion of the film in the passageway so as to generate a capacitance which will vary directly with the amount of moisture content in the film.

Abstract: A method and system for tracking the position of at least one moving object, such as, an airborne meteorological instrument from a ground processing station by intercepting wideband spread spectrum signals transmitted from a plurality of satellites in which the code sequence of the signals is not known comprises a receiver circuit in the moving object which compresses the wideband signals received into a narrow band, removes any frequency bias with a reference oscillator having a frequency offset value, forms a narrow analog base-band and transmits to the processing station at which spectral lines are produced and compared with synthetic spectrum values to determine the identity of each satellite, the reference oscillator frequency offset value is estimated, and the location and velocity of the moving object is determined.

Abstract: A radiosonde has a novel and improved measuring circuitry for measuring atmospheric conditions, such as, temperature, humidity and pressure through the direct conversion of resistance and capacitance values into binary numbers. The binary numbers are transmitted in digital form along with calibration coefficients to a remote ground station. The measuring circuitry can be mounted on the same substrate with the pressure transducer, and the electrical connections between the pressure transducer and measuring circuitry are simplified by utilization of an offset diaphragm, pressure cell arrangement.