Direction finding and ranging system for locating scanning emitters

Claim 1

An apparatus for passively locating a distant scanning source of radiant energy transmission, comprising: first, second and third receiving devices arranged in a spatial array that forms a triangle in which said devices are located at the apexes of said triangle having a side designated AB between said first and second receiving devices, a side AC between said first and third receiving devices and a side BC between said second and third receiving devices, wherein the lengths of said sides are l AB , l AC , l BC , respectively and the interior angles at the apexes are α associated with said first device, β associated with said second device and γ associated with said third device, each of said devices being responsive to the receipt of said radiant energy transmission to produce an electrical signal representative thereof such that when said array is oriented generally coplanar with a scan sweep of said transmission, the resulting electrical signals from at least two differently constituted pairs of said devices have a measurable time differential; time differential signal processing means coupled to said devices for producing at least first and second time differential signals representing said measurable time differentials associated with said two differently constituted pairs of devices; and at least a first angle of arrival processor means having inputs coupled to receive said first and second time differential signals and having an output, said first angle of arrival processor means producing at said output a first signal representing a first angular direction at which said transmission arrives at said array measured as the following function of said first and second time differential signals which are respectively represented by t AB and t BC : ##EQU10## wherein φ 1 is an angle referenced to the side of said triangle designated AB and represents said first angular direction.

Claim 2

An apparatus for passively locating a distant scanning source of radiant energy transmission, comprising: first, second and third receiving devices arranged in a spatial array that forms a triangle in which said devices are located at the apexes of said triangle having a side designated AB between said first and second receiving devices, a side AC between said first and third receiving devices and a side BC between said second and third receiving devices, wherein the lengths of said sides are l AB , l AC , l BC , respectively and the interior angles at the apexes are α associated with said first device, β associated with said second device and γ associated with said third device, each of said devices being responsive to the receipt of said radiant energy transmission to produce an electrical signal representative thereof such that when said array is oriented generally coplanar with a scan sweep of said transmission, the resulting electrical signals from at least two differently constituted pairs of said devices have a measurable time differential; time differential signal processing means coupled to said devices for producing at least first and second time differential signals representing said measurable time differentials associated with said two differently constituted pairs of devices; and at least a first angle of arrival processor means having inputs coupled to receive said first and second time differential signals and having an output, said first angle of arrival processor means producing at said output a first signal representing a first angular direction at which said transmission arrives at said array measured as the following function of said first and second time differential signals which are respectively represented by t AB and t BC : ##EQU10## wherein φ 1 is an angle referenced to the side of said triangle designated AB and represents said first angular direction.

Claim 11

An apparatus for passively locating a distant scanning source of radiant energy transmission, comprising: first, second and third receiving devices arranged in a spatial array that forms a triangle in which said devices are located at the apexes of said triangle, each of said devices being responsive to the receipt of said radiant energy transmission to produce an electrical signal representative thereof such that when said array is oriented generally coplanar with a scan sweep of said transmission, the resulting electrical signals from at least two differently constituted pairs of said devices have a measurable time differential; time differential signal processing means coupled to said devices for producing at least first and second time differential signals representing said measurable time differentials associated with said two differently constituted pairs of devices; at least a first angle of arrival processor means having inputs coupled to receive said first and second time differential signals and having an output, said first angle of arrival processor means producing at said output a first angle signal representing a first angular direction at which said transmission arrives at said array measured as a function of said first and second time differential signals; and scan rate detector means for detecting a scan rate ω s of said source of transmission and for producing a signal representative thereof, and range processor means having a first input for receiving said first angle signal from said output of said first angle of arrival processor representing a measured angle of arrival and having a second input for receiving a signal representing a time differential between a predetermined pair of said first, second and third receiving devices with respect to which the angle of arrival represented by said first angle signal is referenced and a third input for receiving the signal representing said scan rate ω s from said detector means, and wherein said range processor means has an output at which a signal is produced which varies as a function of a distance between said array and said source of transmission.

Claim 12

An apparatus for passively locating a distant scanning source of radiant energy transmission, comprising: first, second and third receiving devices arranged in a spatial array that forms a triangle in which said devices are located at the apexes of said triangle, each of said devices being responsive to the receipt of said radiant energy transmission to produce an electrical signal representative thereof such that when said array is oriented generally coplanar with a scan sweep of said transmission, the resulting electrical signals from at least two differently constituted pairs of said devices have a measurable time differential; time differential signal processing means coupled to said devices for producing at least first and second time differential signals representing said measurable time differentials associated with said two differently constituted pairs of devices; at least a first angle of arrival processor means having inputs coupled to receive said first and second time differential signals and having an output, said first angle of arrival processor means producing at said output a first angle signal representing a first angular direction at which said transmission arrives at said array measured as a function of said first and second time differential signals; and scan rate detector means for detecting a scan rate ω s of said source of transmission and for producing a signal representative thereof, and range processor means having a first input for receiving said first angle signal from said output of said first angle of arrival processor representing a measured angle of arrival and having a second input for receiving a signal representing a time differential between a predetermined pair of said first, second and third receiving devices with respect to which the angle of arrival represented by said first angle signal is referenced and a third input for receiving the signal representing said scan rate ω s from said detector means, and wherein said range processor means has an output at which a signal is produced which varies as a function of a distance between said array and said source of transmission.

Claim 13

An apparatus for passively locating a distant scanning source of radiant energy transmission, comprising: first, second and third receiving devices arranged in a spatial array that forms a triangle in which said devices are located at the apexes of said triangle, each of said devices being responsive to the receipt of said radiant energy transmission to produce an electrical signal representative thereof such that when said array is oriented generally coplanar with a scan sweep of said transmission, the resulting electrical signals from at least two differently constituted pairs of said devices have a measurable time differential; time differential signal processing means coupled to said devices for producing first, second and third time differential signals representing said measurable time differentials associated with said three differently constituted pairs of devices; a first angle of arrival processor means having inputs coupled to receive said first and second time differential signals and having an output, said first angle of arrival processor means producing at said output a first angle signal representing a first angular direction at which said transmission arrives at said array measured as a function of said first and second time differential signals; a second angle of arrival processor means having inputs coupled to receive said first and third time differential signals and having an output, for producing at such output a second angle signal representing said first angular direction as a function of said first and third time differential signals; and a third angle of arrival processor means having inputs coupled to receive said second and third time differential signals and having an output, for producing at such output a third angle signal representing said first angular direction as a function of said second and third time differentials signals; and a scan rate detector means for producing a signal representing a scan rate ω s of said source of transmission, and a range processor means, said range processor means having a first input for receiving one of said first, second and third angle signals respectively from said first, second and third angle of arrival processor means representing said first angular direction, a second input for receiving a signal representing one of said first, second or third time differentials produced by said time differential signal processing means, and at least a third input for receiving a signal representing said scan rate ω s from said scan rate detector means, said range processor means having an output at which a signal is produced that is proportional to a distance of said source of transmission from said array as a function of signals applied to said first, second and third inputs.

Claim 14

An apparatus for passively locating a distant scanning source of radiant energy transmission, comprising: first, second and third receiving devices arranged in a spatial array that forms a triangle in which said devices are located at the apexes of said triangle, each of said devices being responsive to the receipt of said radiant energy transmission to produce an electrical signal representative thereof such that when said array is oriented generally coplanar with a scan sweep of said transmission, the resulting electrical signals from at least two differently constituted pairs of said devices have a measurable time differential; time differential signal processing means coupled to said devices for producing first, second and third time differential signals representing said measurable time differentials associated with said three differently constituted pairs of devices; a first angle of arrival processor means having inputs coupled to receive said first and second time differential signals and having an output, said first angle of arrival processor means producing at said output a first angle signal representing a first angular direction at which said transmission arrives at said array measured as a function of said first and second time differential signals; a second angle of arrival processor means having inputs coupled to receive said first and third time differential signals and having an output, for producing at such output a second angle signal representing said first angular direction as a function of said first and third time differential signals; and a third angle of arrival processor means having inputs coupled to receive said second and third time differential signals and having an output, for producing at such output a third angle signal representing said first angular direction as a function of said second and third time differentials signals; and a scan rate detector means for producing a signal representing a scan rate ω s of said source of transmission, and a range processor means, said range processor means having a first input for receiving one of said first, second and third angle signals respectively from said first, second and third angle of arrival processor means representing said first angular direction, a second input for receiving a signal representing one of said first, second or third time differentials produced by said time differential signal processing means, and at least a third input for receiving a signal representing said scan rate ω s from said scan rate detector means, said range processor means having an output at which a signal is produced that is proportional to a distance of said source of transmission from said array as a function of signals applied to said first, second and third inputs.

Claim 16

A method of locating a distant source of scanning radiant energy transmission, comprising the steps of: receiving said transmission at each of first, second and third receiving devices that have been arranged in a triangular array which lies generally coplanar with a scan sweep of said transmission, and in which said first, second and third receiving devices are disposed at the apexes of said triangular array; developing electrical time differential signals from the receipt of said transmission by at least two differently constituted pairs of said first, second and third receiving devices; processing said time differential signals so as to produce a first output signal representing a first angular direction at which said transmission arrives at said array as a predetermined function of said time differential signals; and detecting a scan rate ω s of said source of transmission and producing a signal representative of said scan rate ω s , and processing said signals representing said first angular direction and a corresponding one of said time differentials together with said signal representing said scan rate ω s to yield a signal representing a range measurement of the distance between said array and said source.

Claim 17

A method of locating a distant source of scanning radiant energy transmission, comprising the steps of: receiving said transmission at each of first, second and third receiving devices that have been arranged in a triangular array which lies generally coplanar with a scan sweep of said transmission, and in which said first, second and third receiving devices are disposed at the apexes of said triangular array; developing electrical time differential signals from the receipt of said transmission by at least two differently constituted pairs of said first, second and third receiving devices; processing said time differential signals so as to produce a first output signal representing a first angular direction at which said transmission arrives at said array as a predetermined function of said time differential signals; and detecting a scan rate ω s of said source of transmission and producing a signal representative of said scan rate ω s , and processing said signals representing said first angular direction and a corresponding one of said time differentials together with said signal representing said scan rate ω s to yield a signal representing a range measurement of the distance between said array and said source.