Radar Detection of Boost-to-Glide Targets via PRF Segmentation

Solution Overview

Problem

Existing radar systems struggle to effectively detect and track near-space hypersonic targets with boost-to-glide trajectories due to slant range ambiguity, low observability, and maneuverability, which leads to challenges in obtaining true ranges and maintaining high signal-to-noise ratios.

Innovation Solution

The method involves configuring an alternating pulse repetition frequency model for radar ranging, defining an extended non-coherent accumulation model in a distance-time plane for target detection, and configuring an S-type recursive energy tracking model for target tracking. This approach addresses slant range ambiguity, low observability, and boost-to-glide maneuvering by ensuring sufficient energy for coherent accumulation and accurate target detection and tracking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multi-pulse repetition frequency method is used to solve slant range ambiguity, then slant range ambiguity is resolved, but coherent accumulation detection energy is insufficient due to allocation across multiple frequencies

Engineering Contradiction:

Improverange measurement accuracyVSAvoidcoherent accumulation detection energy

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the detection process into two distinct phases: a coherent accumulation phase using a single pulse repetition frequency to build sufficient detection energy, and a multi-frequency ranging phase to resolve slant range ambiguity. This temporal segmentation allows each phase to optimize for its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements periodic alternation between different pulse repetition frequencies, where the radar switches between a first PRF for coherent accumulation and a second PRF for ambiguity resolution. This periodic action enables the system to cycle through energy accumulation and measurement disambiguation in a structured manner.

Inventive Principle:

Principle #19Periodic action

2Measurement precision

If coherent accumulation is performed over multiple pulse repetition frequencies to solve slant range ambiguity, then range ambiguity is resolved, but target detection fails under low signal-to-noise ratio conditions

Engineering Contradiction:

Improverange measurement accuracyVSAvoidtarget detection reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent segments the detection process into two distinct phases: a coherent accumulation phase using a single pulse repetition frequency to build sufficient detection energy, and a multi-frequency ranging phase to resolve slant range ambiguity. This temporal segmentation allows each phase to optimize for its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements periodic alternation between different pulse repetition frequencies, where the radar switches between a first PRF for coherent accumulation and a second PRF for ambiguity resolution. This periodic action enables the system to cycle through energy accumulation and measurement disambiguation in a structured manner.

Inventive Principle:

Principle #19Periodic action

3Loss of time

If radar detects hypersonic targets from great distance for early warning, then early warning capability is improved, but slant range ambiguity occurs making true range determination difficult

Engineering Contradiction:

Improveearly warning timeVSAvoidrange measurement accuracy

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The patent implements periodic alternation between different pulse repetition frequencies, where the radar switches between a first PRF for coherent accumulation and a second PRF for ambiguity resolution. This periodic action enables the system to cycle through energy accumulation and measurement disambiguation in a structured manner.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent uses feedback from the coherent accumulation detection results to guide the multi-frequency ranging process. The system accumulates energy to detect target presence, then uses the accumulated data to inform the ambiguity resolution process, creating a feedback loop that improves both detection and measurement accuracy.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20250123384A1Method for detecting and tracking low-observable target with boost-to-glide trajectory under condition of ambiguous slant range

Publication Date: 2025.04.17 NAVAL AVIATION UNIV

AI summary

The present disclosure provides a method for detecting and tracking a low-observable target with a boost-to-glide trajectory under a condition of slant range ambiguity, and belongs to the field of detection and tracking of near-space hypersonic targets. The method includes: configuring an alternating pulse repetition frequency model for radar ranging; defining an extended non-coherent accumulation model in a distance-time plane for target detection; configuring an S-type recursive energy tracking model for target tracking; designing a recursive energy filter, conducting update by recursive energy to keep target tracking at a high signal-to-noise ratio, and obtaining a target trajectory by using a filter algorithm. According to the method of the present disclosure, pulse repetition frequencies within a same sampling period are designed to a constant value, so that there is enough energy for coherent accumulation detection.