Abstract: The present invention combines the relative insensitivity of the phase angle differences of a radio signal to the signal distortions inherent in an urban environment with digital signal processing techniques to produce an accurate and economical way to locate a mobile transmitter station such as a mobile telephone in a cellular telephone network. Phase angle measurements indicative of the angle of direction of a mobile transmitter station from each of a plurality of land stations are obtained by translated Hilbert transformation and are processed to produce a probability density function. The probability density functions are combined after a CHI-squared analysis to produce an area of uncertainty representing the position of the mobile transmitter station. The radio frequency signals emitted from the mobile transmitter station need have no special characteristic for the localization process.

Abstract: An aircraft locating system identifies on a TV format radar display the position of a specific aircraft based on an RF transmission from the aircraft on an RF channel. The locating system includes at least a pair of receive stations located within several miles of an airport and separated by a base line which is in near proximity to at least one runway at the airport or a theoretical extension thereof. Each receive station includes a passive receiver for determining a bearing angle to a source of RF on the RF channel for generating a signal representative of the bearing angle.The locating system further includes a processor which is responsive to bearing angle signals derived from the receive stations for generating line count and line delay information. The line count and line delay information correlate a position determined by the bearing angle signals from at least a pair of receive stations with a frame of reference of the TV display.

Abstract: A golf playing arrangement which includes a fairway, a tee area at one end of the fairway, a plurality of radar ground surveillance units located on the fairway at successively greater distance from the tee area, a central processing unit and a video display terminal and putting green adjacent the tee area. Each of the ground surveillance units detects golf balls moving on the ground in a predetermined circular area containing the unit. The central processing unit calculates and the computer terminal visually displays the distance of the unit furthest from the tee area which detects a golf ball moving therethrough, and the sum of a succession of such distances. This arrangement permits a golfer to play a golf-like game without the need to follow a ball from tee to green.

Abstract: A passive system and related methods for detecting the location of a plurality of N targets by using two X-beam antenna systems and by (i) measuring the time delay between receipt of signals in the two planes of each X-beam which are received directly from the target and by (ii) measuring the time delay between the receipt of signals in the two planes of each X-beam which signals are emitted by the target but reflected from a remote surface. By known these two time delays for each antenna system, the heights of the antenna systems, the fixed angle between the two planes of the X-beam for each system, and the rate of rotation of the X-beam for each system, a direct calculation is established to determine the altitude of each target as viewed from each of the two antenna systems. Bearing or azimuth angles are determined for each target at each antenna system, and the actual N target locations of the N.sup.