초록 ▼

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 atmosph

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.

대표청구항 ▼

A passive ranging system for determining the distance from a radio-silent ground station to a drifting radiosonde, comprising in combination: first receiver means within the radiosonde for detecting range tone signals of constant frequency transmitted from remote radio beacons at diverse geographic

A passive ranging system for determining the distance from a radio-silent ground station to a drifting radiosonde, comprising in combination: first receiver means within the radiosonde for detecting range tone signals of constant frequency transmitted from remote radio beacons at diverse geographic locations of known finite distances relative to the ground station, each of the signals being unique to a respective beacon; oscillator means within the radiosonde for providing data tone signals of frequencies indicative of ambient meteorological data; transmitter means within the radiosonde coupled to said first receiver means and said oscillator means for retransmitting the unique range tone signals; second receiver means at the ground station for detecting the retransmitted unique range tone signals; third receiver means at the ground station for detecting the unique range tone signals transmitted by wireless links from said beacons; selector means coupled to said third receiver means for providing an output of one of the unique signals and an address signal corresponding thereto; filter means coupled to said selector means for providing an output of the unique signal corresponding to the address signal; first and second phase-lock loop means respectively coupled to said selector means and said filter means for sampling and tracking at selected intervals the output signals thereof; comparator means coupled to said first and second loop means for providing an output of the phase lag between the sampled and tracked signals; generating means providing outputs of the direction from the ground station to the radiosonde, and of the distance between the ground station and the beacon transmitting the selected unique signal; and computer means coupled to said comparator means and said generator means for providing an output of the distance from the ground station to the radiosonde as a function of the generating means signals and the phase lag; whereby the position and presence of the ground station is undetectable by radiolocation.