Radar Signal Integration for Small RCS Target Detection

Solution Overview

Problem

Conventional radar devices face difficulties in detecting targets with small radar cross-section (RCS) due to low power of reflected pulses, as they require coherent integration over multiple coherent processing intervals (CPIs, which limits detection range and accuracy.

Innovation Solution

The radar device incorporates a transmitter, radio module, pulse compressor, Doppler filter processor, signal processor, integration processor, estimation module, and target detector, which perform pulse compression, coherent integration, and incoherent integration to estimate target position and velocity, allowing for increased detection range by integrating data across multiple scans and using likelihood calculations to enhance detection probability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If coherent integration is performed using DFT for each CPI, then detection accuracy is improved, but detection range is limited for targets with small RCS

Engineering Contradiction:

Improvedetection accuracyVSAvoiddetection range

Core Design Contradiction:

Measurement precisionVSLength of moving object

Solution Approach 1:

The patent performs pulse compression processing on received pulses before coherent integration. By pre-compressing the pulses to improve signal energy concentration, the system enhances the signal-to-noise ratio earlier in the processing chain, enabling effective detection of small RCS targets at longer ranges while maintaining detection accuracy through subsequent coherent integration.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If multiple CPIs are integrated to detect small RCS targets, then detection probability increases, but processing time increases

Engineering Contradiction:

Improvedetection probabilityVSAvoidprocessing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent performs pulse compression processing on received pulses before coherent integration. By pre-compressing the pulses to improve signal energy concentration, the system enhances the signal-to-noise ratio earlier in the processing chain, enabling effective detection of small RCS targets at longer ranges while maintaining detection accuracy through subsequent coherent integration.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent dynamically adjusts the integration strategy by performing incoherent integration across multiple scans after initial coherent integration. This dynamic approach allows the system to accumulate detection probability over time while managing processing load, as the incoherent integration of detection results is computationally less intensive than continuous coherent integration across all scans.

Inventive Principle:

Principle #15Dynamics

3Length of moving object

If incoherent integration is performed across multiple scans, then detection range increases, but detection accuracy may deteriorate

Engineering Contradiction:

Improvedetection rangeVSAvoiddetection accuracy

Core Design Contradiction:

Length of moving objectVSMeasurement precision

Solution Approach 1:

The patent segments the detection process into two distinct stages: first performing coherent integration within each CPI to maintain detection accuracy and resolve velocity information, then performing incoherent integration across multiple scans to extend detection range. This segmentation allows each integration method to operate in its optimal performance regime, preserving accuracy while extending range.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs pulse compression processing on received pulses before coherent integration. By pre-compressing the pulses to improve signal energy concentration, the system enhances the signal-to-noise ratio earlier in the processing chain, enabling effective detection of small RCS targets at longer ranges while maintaining detection accuracy through subsequent coherent integration.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enables the detection of targets at greater distances with lower required signal-to-noise ratio (SNR) and increased detection probability, even for targets with small RCS, by integrating data across multiple scans and using likelihood calculations to improve detection accuracy.

Implementation Method 1

The Doppler filter processor performs coherent integration on a plurality of range bin data items generated for each direction to generate a range bin data item for each frequency bin

Methodology Applied

Scientific EffectDoppler effect: Doppler Effect

Implementation Method 2

The pulse compressor performs pulse compression on the received pulses to generate a range bin data item for each of the received pulses

Methodology Applied

Scientific EffectPulse compression:

Data Source

PatentUS8810446B2Radar device, radar receiver, and target detection method

Publication Date: 2014.08.19 KK TOSHIBA

AI summary

According to one embodiment, a radar device includes a radio module, a pulse compressor, a Doppler filter processor, a signal processor, an integration processor, an estimation module and a target detector. The radio module receives a plurality of received pulses corresponding to transmission pulses transmitted from a transmitter. The integration processor generates third data by integrating first data generated at the signal processor with second data generated based on first data obtained by a previous scan. The estimation module estimates a position at a time of a next scan based on the third data to generate second data. The target detector detects a target based on the third data.