Systems and methods for antenna analysis and validation

• US 10,302,743 B2
• Filed: 06/09/2015
• Issued: 05/28/2019
• Est. Priority Date: 06/09/2015
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Huard, Andrew, Larussi, Amedeo, Mcinturff, Kim
• Primary Examiner(s): Bythrow, Peter M
• Assistant Examiner(s): Pervin, Nuzhat
• Application Number:
  US14/734,844
• Publication Number:
  US 20180113194A1
• Time in Patent Office: 1,449 Days
• Field of Search: 342173
• CPC Class Codes: G01S 3/023 Monitoring or calibrating
• CPC Class Codes: G01S 3/14 Systems for determining direction or deviation from predetermined direction aerial arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00; combinations of different interacting aerial units for giving a desired directional characteristic H01Q21/29; aerials or aerial systems providing at least two radiation patterns H01Q25/00
• CPC Class Codes: G01S 7/021 Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals
• CPC Class Codes: G01S 7/4004 of parts of a radar system
• CPC Class Codes: G06N 20/00 Machine learning

Abstract

Systems and methods are disclosed herein which facilitate generating and utilizing look-up tables for determining an AoA of a radar signal received from an emitter. In example embodiments, the systems and methods may involve a selectivity process for selecting, for each of a plurality of installation positions, an installation-representative antenna pattern as selected from an option set. Thus, the selectivity process may, for example, include indexing a plurality of data sets of antenna patterns associated with an antenna position and selecting a most representative data set from at least one of the indexed data sets. In some embodiments, the system and methods may further apply a compression algorithm which identifies changes in slope with respect to adjacent pairs of antenna positions (vertex pairs) in the look-up table. The algorithm may then discard any antenna position (any vertex) that does not meet a slope difference threshold with respect to changes in the slope.

Claims

1. A method for generating a look-up table for determining an angle of arrival (AoA) of a radar signal received from an emitter, the method comprising:

a. for each of a plurality of antenna installation positions, selecting an installation-representative antenna pattern from an indexed plurality of data sets of antenna patterns associated with the antenna installation position, wherein the selected installation-representative antenna patterns are a most representative data set as scored against a predetermined set of weighted criteria; and

b. calculating and recording in the look-up table differences between the selected installation-representative patterns for each set of adjacent antenna installation positions of the plurality of antenna installation positions,

wherein the indexed plurality of data sets of antenna patterns includes a plurality of measured family-representative installed antenna patterns,

wherein the measured family-representative installed antenna patterns are calculated by normalizing a set of measured installed antenna patterns to fit an average antenna chamber pattern for a family of measured chamber antenna patterns,

wherein the indexed plurality of data sets further includes mirrored antenna patterns of the measured family-representative installed antenna patterns for other antenna installation positions, mirrored with respect to a mounting platform, and

wherein, for each antenna installation position;

each indexed antenna pattern, comprising an original and mirrored family average chamber pattern and measured family-representative installed antenna pattern set, is graphically superimposed; and

the measured chamber patterns are adjusted such that a chamber mechanical boresight angle matches an installed mechanical boresight angle.

2. The method of claim 1, wherein the selected installation-representative antenna patterns are stored in a selectivity table.

3. The method of claim 1, wherein mirrored antenna patterns are mirrored front to back.

4. The method of claim 1, wherein mirrored antenna patterns are mirrored side to side.

5. The method of claim 1, wherein the indexed plurality of data sets further includes mirrored antenna patterns of the measured family-representative installed antenna patterns, mirrored with respect to the antenna.

6. The method of claim 1, wherein the plurality of data sets of antenna patterns are evaluated with respect to each of a plurality of angle bins around a boresight.

7. The method of claim 1, wherein selecting the installation-representative antenna pattern from the indexed plurality of data sets includes scoring each indexed data set against the predetermined set of weighted criteria and choosing a data set having the greatest possible score.

8. The method of claim 1, wherein a training set of preselected antenna patterns is utilized to facilitate determining relative weighting factors for the predetermined set of weighted criteria.

9. The method of claim 1, wherein a machine learning approach is applied to determine a scoring algorithm as a function of the predetermined set of weighted criteria.

10. The method of claim 1, wherein the differences between selected installation-representative patterns for each set of adjacent installation positions is indexed by true azimuth angle.

11. The method of claim 1, wherein a ratio of antenna pattern gains is calculated for each set of adjacent installation positions based on the selected installation-representative antenna patterns for those positions.

12. The method of claim 11, wherein the ratio of antenna pattern gains is expressed as a difference in decibel units.

13. The method of claim 11, wherein the calculation of the ratio of antenna pattern gains uses an optimized monotonic process.

14. The method of claim 13, wherein the ratio of antenna pattern gains is calculated based on an absolute value of the difference between optimized monotonic fits for the selected installation-representative antenna patterns.

15. The method of claim 1, wherein the look-up table relating pattern difference data with respect to antenna installation position is utilized to calculate the AoA of a radar signal.

16. The method of claim 11, further comprising compressing the data in the look-up table utilizing a compression algorithm which (i) identifies changes in the ratio of antenna pattern gains with respect to adjacent pairs of antenna installation positions in the look-up table and (ii) discards any antenna installation position that does not meet a threshold with respect to the changes in the ratio of antenna pattern gains.

17. The method of claim 16, wherein at least a portion of the compressed data is represented linearly.

18. The method of claim 16, wherein at least a portion of the compressed data is represented by a piecewise function calculated based in part on points of inflection where the ratio of antenna pattern gains changes sign.