Method for direction finding by means of monopulse formation

• US 8,736,485 B2
• Filed: 11/22/2011
• Issued: 05/27/2014
• Est. Priority Date: 11/27/2010
• Status: Active Grant

• Current Assignee: Airbus DS Electronics And Border Security GmbH
• Original Assignee: EADS Deutschland GmbH (Airbus SE)
• Inventors: Schneider, Robert
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US13/302,117
• Publication Number:
  US 20120133548A1
• Time in Patent Office: 917 Days
• Field of Search: 342149-152, 342/80, 342/165, 342173-174
• US Class Current: 342/149
• CPC Class Codes: G01S 13/4418 with means for eliminating radar-dependent errors in angle measurements, e.g. multipath effects
• CPC Class Codes: G01S 13/4436 with means specially adapted to maintain the same processing characteristics between the monopulse signals
• CPC Class Codes: G01S 13/4445 amplitude comparisons monopulse, i.e. comparing the echo signals received by an antenna arrangement with overlapping squinted beams
• CPC Class Codes: G01S 13/4454 phase comparisons monopulse, i.e. comparing the echo signals received by an interferometric antenna arrangement
• CPC Class Codes: G01S 13/4463 using phased arrays
• CPC Class Codes: G01S 7/40 Means for monitoring or calibrating
• CPC Class Codes: G01S 7/4026 Antenna boresight
• CPC Class Codes: G01S 7/403 in azimuth, i.e. in the horizontal plane
• CPC Class Codes: G01S 7/4034 in elevation, i.e. in the vertical plane

Abstract

A method for direction finding by means of monopulse formation in a radar system with electronically controlled group antenna and analog beam shaping of sum and difference channels, a self-test of the antenna being carried out to identify failed receiving elements, and the result of the self-test going directly into the monopulse formation and the test thereby being error corrected. The result of the self-test is converted into correction values that, independently of the antenna viewing direction, are combined with those from the sum channel signal and the difference channel signals of the antenna.

Claims

1. A method for direction finding by means of monopulse formation in a radar system with electronically controlled group antenna and analog beam shaping of sum and difference channels, the method comprising:

performing a self-test of the antenna to identify failed receiving elements, and a result of the self-test goes directly into the monopulse formation and said test is thereby error corrected;

converting the result of the self-test into correction values (C, μ

_x, μ

_y) that, independently of the antenna viewing direction, are combined as follows with those from the sum channel signal (Σ

) and the difference channel signals (Δ

_x,Δ

_y) of the antenna;

2. The method as claimed in claim 1, wherein the following parameters of group antenna feature in the calculation of the correction values (C, μ

_x, μ

_y);

positions (x_n, y_n) of the receiving elements on an antenna aperture relative to the center thereof, and

actual amplitude weightings (g_n) of the receiving elements on the antenna aperture.

3. The method as claimed in claim 1, wherein, in addition to the failed receiving elements identified by the self-test, known amplitude and phase errors of the receiving elements, or structural deviations of an antenna aperture from an ideal case of a symmetrical divisibility, also feature in the monopulse formation.

4. The method as claimed in claim 2, wherein, in addition to the failed receiving elements identified by the self-test, known amplitude and phase errors of the receiving elements, or structural deviations of the antenna aperture from an ideal case of a symmetrical divisibility, also feature in the monopulse formation.