US 6,856,279 B2 · Methods and apparatus for determining an interferometric angle to a target in body coordinates

Abstract

A method for processing radar return data to determine a physical angle, in aircraft body coordinates to a target, is disclosed. The radar return data includes a phase difference between radar return data received at an ambiguous radar channel and a left radar channel, a phase difference between radar return data received at a right radar channel and an ambiguous radar channel, and a phase difference between radar return data received at a right radar channel and a left radar channel. The method includes adjusting a phase bias for the three phase differences, resolving phase ambiguities between the three phase differences to provide a signal, and filtering the signal to provide a physical angle to the target in aircraft body coordinates.

Claims14

Dependent claims

A method for processing radar return data to determine a physical angle, in aircraft body coordinates to a target, the radar return data including a phase difference between radar return data received at an ambiguous radar channel and a left radar channel, a phase difference between radar return data received at a right radar channel and an ambiguous radar channel, and a phase difference between radar return data received at a right radar channel and a left radar channel, said method comprising:

adjusting a phase bias for the three phase differences;
resolving phase ambiguities between the three phase differences to provide a signal;
and
filtering the signal to provide a physical angle to the target in aircraft body coordinates.

1 more element

A processor configured to:

resolve phase ambiguities between multiple received phase difference signals by determining a plurality of physical angle solutions for each received phase difference;
and
determine a physical angle in aircraft body coordinates to a target based upon the resolved phase ambiguities, the phase difference signals having been determined based upon radar return data received at each of an ambiguous radar channel, a left radar channel, and a right radar channel.

A radar signal processing circuit comprising:

a radar gate correlation circuit configured to sample radar return data from left, right, and ambiguous radar channels at a sampling rate;
a correlation bass pass filter configured to stretch the sampled radar return data to a continuous wave (CW) signal;
a mixer configured to down sample an in-phase component and a quadrature component of the CW signal to a doppler frequency;
a band pass filter centered on the doppler frequency;
a phase processor configured to receive processed radar return data from said band pass filter, said phase processor further configured to determine a phase difference between radar return data from an ambiguous channel and a left channel, a phase difference between radar return data from an right channel and the ambiguous channel, and a phase difference between radar return data from the right channel and the left channel;
and
a processing unit configured to receive the three phase differences, adjust a phase bias for the three phase differences, resolve phase ambiguities between the three phase differences to provide a signal, and filtering the signal to provide a physical angle to a target in aircraft body coordinates.

4 more elements

Dependencies are inferred from the claim text.

Methods and apparatus for determining an interferometric angle to a target in body coordinates

Life of this patent

Methods and apparatus for determining an interferometric angle to a target in body coordinates

Life of this patent

Abstract

Claims14