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A Nonlinear Transform-Based Variability Index CFAR Detector for Doppler-Extended Targets
Lin Cao1,2, Yuxin He1,2, Zongmin Zhao1,2
1Center for Target Cognition Information Processing Science and Technology, Beijing Information Science and Technology University, Beijing 100101, China.
Sensors (Basel, Switzerland)
|March 28, 2026
Summary
A new detector improves radar performance for Doppler-extended targets (DETs) by addressing echo spread. The nonlinear transform-based variability index CFAR (DET-NTVI-CFAR) enhances detection probability and maintains false alarm control in complex environments.
Area of Science:
- Radar Systems Engineering
- Signal Processing
- Target Detection
Background:
- Frequency-modulated continuous-wave (FMCW) radar systems face challenges in detecting Doppler-extended targets (DETs).
- Micro-Doppler effects from extended targets spread echo energy, hindering detection by traditional methods.
- Existing constant false alarm rate (CFAR) detectors struggle with performance degradation and adaptability in complex clutter.
Purpose of the Study:
- To propose a novel detector for improved DET detection in FMCW radar systems.
- To enhance detection probability and ensure stable false alarm control under varying clutter conditions.
- To introduce a nonlinear transform-based variability index CFAR (DET-NTVI-CFAR) detector.
Main Methods:
- A nonlinear transform is applied to accumulated power cells to construct a detection statistic.
- Thresholds are derived from a corresponding probability distribution model.
- A variability index CFAR (VI-CFAR) strategy is employed for adaptive detection branch selection.
- False alarm probability expressions for sub-detection methods guide threshold parameter selection.
Main Results:
- The proposed DET-NTVI-CFAR detector demonstrates stable false alarm control across diverse environments.
- Significant improvements in detection probability are achieved compared to existing methods.
- Simulation results validate the detector's effectiveness in complex clutter backgrounds.
Conclusions:
- The DET-NTVI-CFAR detector offers a robust solution for detecting Doppler-extended targets in FMCW radar.
- The method provides enhanced detection performance and reliable false alarm rate management.
- Field test results confirm the practical applicability of the proposed detector.
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