Near-Field EM-Based Multistatic Radar Range Estimation

TL;DR

This paper introduces a new electromagnetic model for near-field multistatic radar range estimation, demonstrating improved accuracy over traditional methods, especially at high frequencies, with practical automotive applications.

Contribution

A novel near-field electromagnetic model for multistatic radar range estimation and a maximum likelihood estimator that outperforms traditional methods in near-field scenarios.

Findings

Near-field model improves range estimation accuracy.

High carrier frequency enhances radar resolution.

Resolution saturates to traditional limits in far-field.

Abstract

Radar targets are traditionally modelled as point target reflectors, even in the near-field region. Yet, for radar systems operating at high carrier frequencies and small distances, traditional radar propagation models do not accurately model the scatterer responses. In this paper, a novel electromagnetic-based model is thus developed for the multistatic radar detection of a rectangular plate reflector in the near-field region. This model is applied to an automotive scenario, in which a linear antenna array is spread out at the front of a vehicle, and performs a radar measurement of the distance to the back of the vehicle ahead. Based on the developed received signal model, the maximum likelihood estimator of the range is designed. By exploiting the near-field target model, this estimator is shown to provide a significant gain with respect to traditional range estimators. The impact of the system and scenario parameters, i.e. the carrier frequency, bandwidth and distance to the target, is furthermore evaluated. This analysis shows that the radar resolution in the near-field regime is improved at high carrier frequencies, while saturating to the traditional bandwidth-dependent resolution in the far-field region.