Monopulse system for target location
First Claim
1. A method for identifying the locations of plural targets lying within the main beam of a monopulse antenna which includes four ports, namely sum, elevation difference, azimuth difference, and double difference ports, said method comprising the steps of:
- generating a covariance matrix from the sum, elevation difference, azimuth difference, and double difference signals;
determining the number of targets within the main beam based on the eigenvalues of said covariance matrix;
if the number of targets is two, determining, from a system of two-dimensional equations derived from noise eigenvectors of said covariance matrix, the angular locations of said two targets within said main beam.
1 Assignment
0 Petitions
Accused Products
Abstract
A monopulse system generates sum (Σ), elevation difference (ΔEL), azimuth difference (ΔAZ), and double difference (Δ.sub.Δ) signals, and generates a covariance matrix. The covariance matrix is decomposed to produce at least the principal eigenvector. The location or angular direction within the main beam of a single target is determined from the real component of the quotient of elements of the principal eigenvector, by the use of a look-up table. In another embodiment of the invention, the eigenvalues are generated from the covariance matrix, and the number of significant eigenvalues determines the number of targets within the main beam. If a single target is found, its location is found as described above. If two targets are found in the main beam, the locations of the two targets are determined by a closed-form solution of quadratic equations. A missile using a monopulse radar according to an aspect of the invention determines the presence of two targets within the main beam, which targets may be a real target and a decoy, and uses extrinsic information to identify a selected target as being the true target. The missile is homed in the direction of the selected target.
59 Citations
9 Claims
-
1. A method for identifying the locations of plural targets lying within the main beam of a monopulse antenna which includes four ports, namely sum, elevation difference, azimuth difference, and double difference ports, said method comprising the steps of:
-
generating a covariance matrix from the sum, elevation difference, azimuth difference, and double difference signals; determining the number of targets within the main beam based on the eigenvalues of said covariance matrix; if the number of targets is two, determining, from a system of two-dimensional equations derived from noise eigenvectors of said covariance matrix, the angular locations of said two targets within said main beam. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method for controlling a missile for causing it to home on a target which is generating spoofing signals which are radiated within a main beam of a monopulse antenna of said missile, which monopulse antenna includes four ports, namely sum, elevation difference, azimuth difference, and double difference ports, said method comprising the steps of:
-
generating a covariance matrix of said sum, elevation difference, azimuth difference, and double difference signals; determining the number of targets within said main beam based on the eigenvalues of said covariance matrix; if the number of targets is two, determining, from a system of two-dimensional equations derived from noise eigenvectors of said covariance matrix, the angular locations of said two targets within said main beam. from other information, identifying one of said two targets as the selected target; and homing said missile toward said selected target.
-
-
8. A method for identifying the location or angular direction of a single target within the main beam of a monopulse antenna, said method comprising the steps of:
-
generating sum, elevation difference, azimuth difference, and double difference signals from the signals of said monopulse antenna; generating a covariance matrix of said sum, elevation difference, azimuth difference, and double difference signals; determining the direction of said single target by use of at least the principal eigenvector of said covariance matrix. - View Dependent Claims (9)
-
Specification