Conformal array antenna/receiver processor system

Claim 2

A monopluse receiver system for determining the direction to a target comprising: a. a three dimensional antenna array for receiving complex azimuth monopulse sum and difference signals, Sigma and Delta , b. receiver means coupled to the array for producing the ratio of the magnitude of Sigma and Delta , Delta / Sigma , and the phase difference therebetween, < Delta / Sigma , and c. process means coupled to said receiver means for estimating, responsive to monopulse return information, at least the azimuth to a target from a comparison with a predetermined tabulation of said functions Delta / Sigma and < Delta / Sigma .

Claim 3

A system according to claim 1 wherein said processing means includes means for estimating elevation angle to said target.

Claim 4

A receiver according to claim 1 wherein said comparison is a linear estimation of said functions Delta / Sigma and < Delta / Sigma with respect to azimuth.

Claim 5

A monopulse receiver system for determining the direction to a target comprising: a. a three dimensional conformal antenna array for receiving azimuth complex sum and difference monopulse signals, Sigma and Delta , b. receiver means coupled to the array for producing the ratio of the magnitudes of Sigma and Delta , Delta / Sigma , and the phase difference therebetween, < Delta / Sigma , and c. digital memory means coupled to said receiver means for storing the variation of at least the azimuth angle as a function of Delta / Sigma and < Delta / Sigma and producing a signal representative of relative azimuth angle to a target for each of said signals Delta / Sigma and < Delta / Sigma .

Claim 6

A monopulse receiver system for determining the direction to a target comprising: a. a three dimensional conformal antenna array for receiving azimuth complex sum and difference monopulse signals, Sigma and Delta , b. receiver means coupled to the array for producing the ratio of the magnitudes of Sigma and Delta , Delta / Sigma , and the phase difference therebetween, < Delta / Sigma , and c. digital memory means coupled to said receiver means for storing the variation of at least the azimuth angle as a function of Delta / Sigma and < Delta / Sigma and producing a signal representative of relative azimuth angle to a target for each of said signals Delta / Sigma and < Delta / Sigma .

Claim 7

A system according to claim 4 wherein said digital memory means is a read-only memory.

Claim 8

A system according to claim 5 wherein said read only memory further includes means for uniquely defining the elevation angle to said target for each pair of signals Delta / Sigma and < Delta / Sigma .

Claim 9

A system according to claim 4 wherein said antenna is a circular cylindrical array.

Claim 10

A system according to claim 4 wherein said receiver incorporates two parallel channels.

Claim 11

A system according to claim 8 wherein the first channel which has a pair of signals representative of Sigma and Delta as its inputs, comprises: a. a pair of log amplifiers coupled to said Sigma and Delta inputs producing at their outputs the function ln Sigma and ln Delta , respectively, b. A difference circuit coupled to said log amplifiers for producing an output signal ln Delta / Sigma , c. an exponential circuit coupled to said difference circuit for producing an output signal related to Delta / Sigma , and d. an analog to digital converter coupled to the output of said exponential circuit for producing a digital representation of Delta / Sigma .

Claim 12

A system according to claim 9 wherein said second channel has a pair of signals representative of Sigma and Delta as its inputs, comprising: a. a phase detector coupled to said pair of signals to produce an output representative of the phase difference therebetween, < Delta / Sigma , and b. an analog to digital converter coupled to the output of said detector for producing a digital representation of < Delta / Sigma .

Claim 13

A monopulse receiver system for determining the direction to a target comprising: a. a three dimensional antenna array for receiving complex azimuth monopulse sum and difference signals, Sigma and Delta , b. receiver means coupled to the array for producing the ratios of the magnitudes of Delta and Sigma , Delta / Sigma , and the phase difference therebetween, < Delta / Sigma , and c. digital memory means coupled to said receiver means for storing the slope related parameter of the linear estimators of the relationship between Delta / Sigma and the azimuth angle, theta , to said target for various < Delta / Sigma ''s, said slope related parameter defined by the equation: theta K( Delta / Sigma , < Delta / Sigma ) . Delta / Sigma (1) where K( Delta / Sigma , < Delta / Sigma ) is related to the slope of said linear estimators and producing a digital signal representative of the slope parameter for each pair of said Delta / Sigma and < Delta / Sigma signals, and d. combining means coupled to said Delta / Sigma and K( Delta / Sigma , < Delta / Sigma ) signals for producing an output signal representative of relative azimuth as defined by said equation (1) above.

Claim 14

A monopulse receiver system for determining the direction to a target comprising: a. a three dimensional antenna array for receiving complex azimuth monopulse sum and difference signals, Sigma and Delta , b. receiver means coupled to the array for producing the ratios of the magnitudes of Delta and Sigma , Delta / Sigma , and the phase difference therebetween, < Delta / Sigma , and c. digital memory means coupled to said receiver means for storing the slope related parameter of the linear estimators of the relationship between Delta / Sigma and the azimuth angle, theta , to said target for various < Delta / Sigma ''s, said slope related parameter defined by the equation: theta K( Delta / Sigma , < Delta / Sigma ) . Delta / Sigma (1) where K( Delta / Sigma , < Delta / Sigma ) is related to the slope of said linear estimators and producing a digital signal representative of the slope parameter for each pair of said Delta / Sigma and < Delta / Sigma signals, and d. combining means coupled to said Delta / Sigma and K( Delta / Sigma , < Delta / Sigma ) signals for producing an output signal representative of relative azimuth as defined by said equation (1) above.

Claim 15

A monopulse receiver system for determining the direction to a target comprising: a. a three dimensional antenna array for receiving complex azimuth monopulse sum and different signals, Sigma and Delta , b. receiver means coupled to the array for producing the ratios of the magnitudes of Delta and Sigma , Delta / Sigma , and the phase difference therebetween, < Delta /and c. digital memory means coupled to said receiver means for storing the slope and intercept related parameters of the linear segment estimations of the relationship between Delta / Sigma and the azimuth angle, theta , to said target for various < Delta / Sigma , said parameters defined by the equation theta K( Delta / Sigma , < Delta / Sigma ) . Delta / Sigma + B( Delta / Sigma , < Delta / Sigma ) (1) where K( Delta / Sigma , < Delta / Sigma ) is related to the slope of said linear estimators and B( Delta / Sigma , < Delta / Sigma ) is related to the intercept thereof and producing digital signals representative of the slope and intercept parameters for each pair of said Delta / Sigma and < Delta / Sigma signals, and d. combining means coupled to said Delta / Sigma , K( Delta / Sigma , < Delta / Sigma ) and B( Delta / Sigma , < Delta / Sigma ) signals for producing an output signal representative of relative azimuth as defined by said equation (1) above.

Claim 16

A monopulse receiver system for determining the direction to a target comprising: a. a three dimensional antenna array for receiving complex azimuth monopulse sum and different signals, Sigma and Delta , b. receiver means coupled to the array for producing the ratios of the magnitudes of Delta and Sigma , Delta / Sigma , and the phase difference therebetween, < Delta /and c. digital memory means coupled to said receiver means for storing the slope and intercept related parameters of the linear segment estimations of the relationship between Delta / Sigma and the azimuth angle, theta , to said target for various < Delta / Sigma , said parameters defined by the equation theta K( Delta / Sigma , < Delta / Sigma ) . Delta / Sigma + B( Delta / Sigma , < Delta / Sigma ) (1) where K( Delta / Sigma , < Delta / Sigma ) is related to the slope of said linear estimators and B( Delta / Sigma , < Delta / Sigma ) is related to the intercept thereof and producing digital signals representative of the slope and intercept parameters for each pair of said Delta / Sigma and < Delta / Sigma signals, and d. combining means coupled to said Delta / Sigma , K( Delta / Sigma , < Delta / Sigma ) and B( Delta / Sigma , < Delta / Sigma ) signals for producing an output signal representative of relative azimuth as defined by said equation (1) above.

Claim 17

A system according to claim 12 wherein said receiver means incorporates two parallel channels.

Claim 18

A system according to claim 13 wherein the first channel which has a pair of signals representative of Sigma and Delta as its inputs, comprises: a. a pair of log amplifiers coupled to said Sigma and Delta inputs producing at their outputs the function ln Sigma and ln Delta , respectivelY, b. a difference circuit coupled to said log amplifiers for producing an output signal ln Delta / Sigma , c. an exponential circuit coupled to said difference circuit for producing an output signal related to Delta / Sigma , and d. an analog to digital converter coupled to the output of said exponential circuit for producing a digital representation of Delta / Sigma .

Claim 19

A system according to claim 14 wherein said second channel has a pair of signals representative of Sigma and Delta as its inputs, comprising: a. a phase detector coupled to said pair of signals to produce an output representative of the phase difference therebetween, < Delta / Sigma , and b. an analog to digital converter coupled to the output of said detector for producing a digital representation of < Delta / Sigma .

Claim 20

A system according to claim 12 wherein said digital memory means is a read-only memory.

Claim 21

A system according to claim 16 further including circuit means coupled to said Delta / Sigma and < Delta / Sigma signals for producing an input address to said ROM which uniquely defines K( Delta / Sigma , < Delta / Sigma ) and B( Delta / Sigma , < Delta / Sigma ).

Claim 22

A system according to claim 17 wherein said combining means comprises: a. a multiplier means coupled to said Delta / Sigma and K( Delta / Sigma , < Delta / Sigma ) signals for producing a multiplier output signal representative of Delta / Sigma . K( Delta / Sigma , < Delta / Sigma ), and b. adder circuit means coupled to said multiplier and said ROM for combining said multiplier output signal with the intercept related function B( Delta / Sigma , < Delta / Sigma ) to produce an adder output signal representative of Delta / Sigma . K( Delta / Sigma , < Delta / Sigma ) + B( Delta / Sigma , < Delta / Sigma ).

Claim 23

A system according to claim 18 further including gross pointing address means to provide an output representative of the pointing angle of said array antenna and adder means coupled to said gross pointing address means and said adder output signal to produce an absolute azimuth angle indication of the target.

Claim 24

A system according to claim 12 wherein said antenna is a circular cylindrical array.

Claim 27

A method according to claim 21 further including the step of estimating the elevation angle to said target from said comparison with a predetermined tabulation of said functions Delta / Sigma and < Delta / Sigma .

Claim 28

A method according to claim 21 wherein said comparison is a linear estimation of said functions Delta / Sigma and < Delta / Sigma with respect to relative azimuth.