Abstract: A passive ranging system for determining the slant range from a ground station to a drifting radiosonde. In one embodiment, the ground station receives meteorological data ranging and internal temperature signals from the radiosonde. The data signals are read out as ambient conditions of the atmosphere and the range signal is phase-compared to a reference signal at periodic intervals. Changes in frequency due to temperature fluctuations in the radiosonde components are factored into the phase-comparison, and the resultant change in phase represents movement of the radiosonde. In another embodiment the range tone from a remote broadcast station is retransmitted by the radiosonde and received at the ground station simultaneously with the same tone directly from the broadcast station. The phase lag is measured and coupled with measurements of direction from the ground station to the radiosonde, and with the distance between the ground station and the broadcast station for determining the slant range.

Abstract: A passive ranging system for determining the slant range from a ground station to a drifting radiosonde. In one embodiment, the ground station receives meteorological data ranging and internal temperature signals from the radiosonde. The data signals are read out as ambient conditions of the atmosphere and the range signal is phase-compared to a reference signal at periodic intervals. Changes in frequency due to temperature fluctuations in the radiosonde components are factored into the phase-comparison, and the resultant change in phase represents movement of the radiosonde. In another embodiment the range tone from a remote broadcast station is retransmitted by the radiosonde and received at the ground station simultaneously with the same tone directly from the broadcast station. The phase lag is measured and coupled with measurements of direction from the ground station to the radiosonde, and with the distance between the ground station and the broadcast station for determining the slant range.

Abstract: A flexible cord and antenna is paid out at a controlled rate from a radiosonde as it is lifted into the upper atmosphere by a balloon. The cord is knit into a tubular body and folded into a compartment in the radiosonde. The extended end is wrapped around the rotor of a centrifugal brake which limits the pay out rate. The knit tubular body unravels as the cord and antenna are paid out.

Abstract: A sensing system and method suitable for use in humidity sensing instruments such as radiosondes to determine the true relative humidity of the atmosphere contemporaneously with other parameters at the same altitude as the radiosonde rises or descends. The indicated relative humidity of the air contiguous with a humidity sensing element and the temperature of the humidity sensor and the surrounding air temperature, remote from the sensor, are measured. The true relative humidity of the surrounding air is determined by the product of the indicated relative humidity and the ratio of the saturated vapor pressure at the sensor temperature to that at the surrounding air temperature.

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.