Method for performing bistatic radar functions

• US 7,369,083 B2
• Filed: 04/25/2006
• Issued: 05/06/2008
• Est. Priority Date: 04/26/2004
• Status: Expired due to Fees

• Current Assignee: Robert D. Budic
• Original Assignee: Robert D. Budic
• Inventors: Budic, Robert D.
• Primary Examiner(s): Sotomayor; John B
• Application Number:
  US11/380,045
• Publication Number:
  US 20070247353A1
• Time in Patent Office: 742 Days
• Field of Search: 342159-162, 342/25.R, 342/25.A, 342/25.B, 342/25.C, 342/25.F, 342/125, 342/126, 342/194, 342/195
• US Class Current: 342/159
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/225 with cyclic repetition of a non-uniform pulse sequence, e.g. staggered PRF
• CPC Class Codes: G01S 13/284 using coded pulses
• CPC Class Codes: G01S 13/5244 Adaptive clutter cancellation specially adapted for airborne MTI, G01S13/5242
• CPC Class Codes: G01S 7/36 Means for anti-jamming , e.g. ECCM, i.e. electronic counter-counter measures
• CPC Class Codes: G01S 7/414 Discriminating targets with respect to background clutter

Abstract

A bistatic radar system having a transmitter that generates unique signals at spatially independent transmitter degrees of freedom and a receiver that filters the signal at each receiver degree of freedom into a group of signals identical in number to the number of transmitter degrees of freedom. The receiver formats the filtered signals into a 2-dimensional array of elements. The receiver rotates the array so that the new axes are aligned with the Doppler gradient. The data is then re-sampled and projected to linearize the clutter signal. The receiver may be integrated with a broad class of adaptive and non-adaptive clutter mitigation approaches such as electronic clutter tuning and projected bistatic space-time adaptive processing, or STAP.

Claims

1. A method of filtering and processing a received radar signal comprising the steps of:

receiving an element-level radar signal;

splitting said element-level radar signal into a plurality of signal components, each said signal component comprising energy scattered by a specific transmit element—

receiver—

element pair;

forming a 2-D array of data associated with a plurality of transmitter and receiver degrees of freedom;

rotating said 2-D array of data;

re-sampling said array of data to find new degrees of freedom; and

using a projection to eliminate residual degrees of freedom.

2. A method of filtering and processing a received radar signal comprising the steps of:

receiving an element-level radar signal;

splitting said element-level signal into a plurality of signal components, each said signal component comprising energy scattered by a specific transmitter element—

receiver element pair;

generating a Complex Ambiguity Function by filtering said plurality of signal components, each filtered signal component comprising energy delayed by a specific value and Doppler shifted by a specific value relative to the direct path signal;

generating a plurality of 4-dimensional labels for components of signal energy; and

performing Reduced Rank STAP processing on said filtered signal components.

3. A method of filtering and processing a received radar signal comprising the steps of

receiving an element level radar signal;

generating a Complex Ambiguity Function by filtering said element-level radar signal into a first plurality of signal components, each of said first plurality of signal components comprising energy delayed by a specific value and Doppler shifted by a specific value relative to the direct path signal;

filtering said Complex Ambiguity Function into a second plurality of signal components, each of said second plurality of signal components comprising energy scattered by a specific transmit element and received by a specific receiver element;

generating a plurality of 4-dimensional labels for components of signal energy; and

performing Reduced Rank STAP processing.