Correlation curvature radar

Claim 2

In a radiant energy system, the combination of five radiant energy receiving stations, one at the center of a circle having a radius of several miles and the others substantially equally spaced along the circumference of the circle, for locating a source of energy at unknown range from said center station and beyond said circle, a coarse delay means, means for setting said coarse delay means sequentially to discrete time delay values approximately equal to the range-independent portion of the difference in arrival time of said energy at pairs of said stations, each pair consisting of one said outer station and the said center station, a fine delay line having a plurality of taps for providing time delays substantially equal to the rangedependent portions of the difference in said arrival times, a separate multiplier circuit connected to each tap of said fine delay line, switch means for sequentially connecting said pairs of stations one at a time through said coarse delay means and said fine delay line to said multiplier circuits, whereby the signals from each pair of stations are sequentially combined in every multiplier circuit, means for separately integrating the output of each multiplier circuit, and means for determining which integrated value is a maximum, whereby the range-dependent time delays of all pairs of stations are determined sequentially.

Claim 3

The combination according to claim 1, wherein said last means includes means for registering the maximum integrated value and inhibiting means for preventing the registration of integrated values less than said maximum.

Claim 4

The combination according to claim 2, including means for removing the integrated values and restoring the inhibiting means to the normal noninhibiting condition.

Claim 5

The combination according to claim 3, wherein said center station includes a directional radar system and said receiving stations receive echoes of the waves transmitted by said directional radar system.

Claim 6

The combination according to claim 4, wherein said means for setting said coarse delay means includes switching means responsive to azimuthal data provided by said directional radar system.

Claim 7

In a radiant energy system, the combination of five omnidirectional radiant energy receiving stations adapted to receive the same signals, one station at the center of a circle having a radius of several miles and the other stations near the ends of orthogonal diameters of said circle, for locating a source of energy at unknown range from said center station and beyond said circle, a coarse time delay means, means for setting said coarse delay means sequentially to discrete time delay values approximately equal to the range-independent portion of the difference in arrival time of said energy at pairs of said stations consisting of one outer station and the center station, a fine delay means having a plurality of taps for providing time delays substantially equal to the range-dependent portions of the difference in said arrival times, a separate multiplier circuit connected to each tap of said fine delay means, switch means for sequentially connecting said pairs of stations through said coarse and fine delay meanS to said multiplier circuits to bring signals of each pair approximately into time coincidence, whereby said multiplier circuits combine the signals from each pair of stations, means for separately integrating the output of each multiplier circuit, and means for only selecting the maximum integrated output, whereby said range-dependent delays of all pairs of stations are determined sequentially.

Claim 8

In a radiant energy system, the combination of five omnidirectional radiant energy receiving stations adapted to receive the same signals, one station at the center of a circle having a radius of several miles and the other stations near the ends of orthogonal diameters of said circle, for locating a source of energy at unknown range from said center station and beyond said circle, a coarse time delay means, means for setting said coarse delay means sequentially to discrete time delay values approximately equal to the range-independent portion of the difference in arrival time of said energy at pairs of said stations consisting of one outer station and the center station, a fine delay means having a plurality of taps for providing time delays substantially equal to the range-dependent portions of the difference in said arrival times, a separate multiplier circuit connected to each tap of said fine delay means, switch means for sequentially connecting said pairs of stations through said coarse and fine delay meanS to said multiplier circuits to bring signals of each pair approximately into time coincidence, whereby said multiplier circuits combine the signals from each pair of stations, means for separately integrating the output of each multiplier circuit, and means for only selecting the maximum integrated output, whereby said range-dependent delays of all pairs of stations are determined sequentially.

Claim 9

In a radiant energy system, the combination of a plurality of radiant energy stations adapted to receive the same signals, one station being at the center of a circle and the other stations being equally spaced along the circumference of said circle, for locating a source of energy at unknown range from said center station and beyond said circle, an adjustable delay means, means for setting said delay means sequentially to time delay values each approximately equal to the range-independent portion of the difference in arrival time of said energy at pairs of said stations consisting of one said outer station and said center station, fine delay means having a plurality of output connections for providing different time delays, said fine delay means providing a delay substantially equal to the range-dependent portion of the difference in said arrival times, a separate multiplier circuit connected to each tap of said fine delay means, switch means for sequentially connecting said pairs of stations through said coarse and fine delay means to said multiplier circuits, whereby every multiplier circuit combines the signals from each pair of stations, means for separately integrating the output of each multiplier circuit, means for determining which integrated output is a maximum, whereby the range-dependent delays of all pairs of stations are determined sequentially.

Claim 10

In a radiant energy system, the combination of a plurality of radiant energy stations adapted to receive the same signals, one station being at the center of a circle and the other stations being equally spaced along the circumference of said circle, for locating a source of energy at unknown range from said center station and beyond said circle, an adjustable delay means, means for setting said delay means sequentially to time delay values each approximately equal to the range-independent portion of the difference in arrival time of said energy at pairs of said stations consisting of one said outer station and said center station, fine delay means having a plurality of output connections for providing different time delays, said fine delay means providing a delay substantially equal to the range-dependent portion of the difference in said arrival times, a separate multiplier circuit connected to each tap of said fine delay means, switch means for sequentially connecting said pairs of stations through said coarse and fine delay means to said multiplier circuits, whereby every multiplier circuit combines the signals from each pair of stations, means for separately integrating the output of each multiplier circuit, means for determining which integrated output is a maximum, whereby the range-dependent delays of all pairs of stations are determined sequentially.

Claim 11

In a radiant energy system, the combination of five like radiant energy receiving stations, one at the center of a circle having a radius of several miles and the others substantially equally spaced along the circumference of said circle, for locating a source of energy at unknown range from said center station and beyond said circle, a coarse delay means, means for setting said coarse delay means sequentially to discrete time delay values approximately equal to the range-independent portion of the difference in arrival time of said energy at pairs of said stations, each pair consisting of one said outer station and said center station, a fine delay line having a plurality of taps for providing time delays substantially equal to the range-dependent portions of the difference in said arrival times, switch means for sequentially connecting said pairs of stations one at a time through said delay means and delay line to bring the signals from the stations of each pair into approximate time coincidence at a particular tap of said fine delay line, and means for identifying that particular tap, whereby the range-dependent delays of all pairs of stations are determined sequentially.

Claim 12

In a radiant energy system, the combination of five like radiant energy receiving stations, one at the center of a circle having a radius of several miles and the others substantially equally spaced along the circumference of said circle, for locating a source of energy at unknown range from said center station and beyond said circle, a coarse delay means, means for setting said coarse delay means sequentially to discrete time delay values approximately equal to the range-independent portion of the difference in arrival time of said energy at pairs of said stations, each pair consisting of one said outer station and said center station, a fine delay line having a plurality of taps for providing time delays substantially equal to the range-dependent portions of the difference in said arrival times, switch means for sequentially connecting said pairs of stations one at a time through said delay means and delay line to bring the signals from the stations of each pair into approximate time coincidence at a particular tap of said fine delay line, and means for identifying that particular tap, whereby the range-dependent delays of all pairs of stations are determined sequentially.

Claim 13

In a radiant energy system, the combination of a plurality of radiant energy receiving stations adapted to receive the same signals, one station at the center of a circle having a radius of several miles and the others at substantially diametrically opposite points on said circle, for locating a source of energy at unknown range from said center station and beyond said circle, an adjustable coarse delay means, means for setting said coarse delay means sequentially to time delay values each approximately equal to the range-independent portion of the difference in arrival time of said energy at pairs of said stations consisting of one said outer station and said center station, fine delay means having a plurality of taps for providing different time delays so that the delay at one particular tap is substantially equal to the range-dependent portion of the arrival times, switch means for sequentially connecting the pairs of stations one pair at a time through the coarse and fine delay means to bring the signals of a pair of stations into approximate time coincidence at said particular tap, and means for identifying said particular tap and registering its value, whereby the range-dependent delays of all pairs of stations are determined sequentially.

Claim 14

In a radiant energy system, the combination of a plurality of radiant energy receiving stations adapted to receive the same signals, one station at the center of a circle having a radius of several miles and the others at substantially diametrically opposite points on said circle, for locating a source of energy at unknown range from said center station and beyond said circle, an adjustable coarse delay means, means for setting said coarse delay means sequentially to time delay values each approximately equal to the range-independent portion of the difference in arrival time of said energy at pairs of said stations consisting of one said outer station and said center station, fine delay means having a plurality of taps for providing different time delays so that the delay at one particular tap is substantially equal to the range-dependent portion of the arrival times, switch means for sequentially connecting the pairs of stations one pair at a time through the coarse and fine delay means to bring the signals of a pair of stations into approximate time coincidence at said particular tap, and means for identifying said particular tap and registering its value, whereby the range-dependent delays of all pairs of stations are determined sequentially.

Claim 15

The combination according to claim 9, wherein the center station includes a directional radar system and said receiving stations receive echoes of the waves transmitted by said directional radar system.

Claim 16

The combination according to claim 10, wherein the means for setting said coarse delay means includes switching means responsive to azimuthal data provided by said directional radar system.