Analyze the FMCW Waveform Skin Return of Moving Objects in the Presence of Stationary Hidden Objects Using Numerical Models

Abstract

In this paper, a high-performance antenna array system model is presented to analyze moving-object-skin-returns and track them in the presence of stationary objects using frequency modulated continuous wave (FMCW). The main features of the paper are bonding the aspects of antenna array and electromagnetic (EM) wave multi-skin-return modeling and simulation (M&S) with the aspects of algorithm and measurement/tracking system architecture. The M&S aspect models both phase and amplitude of the signal waveform from a transmitter to the signal processing in a receiver. In the algorithm aspect, a novel scheme for FMCW signal processing is introduced by combining time- and frequency-domain methods, including a vector moving target indication filter and a vector direct current canceller in time-domain, and a constant false alarm rate detector and a mono-pulse digital beamforming angle tracker in frequency-domain. In addition, unlike previous designs of using M×N fast Fourier transform (FFT) for an M×N array, only four FFTs are used, which tremendously saves time and space in hardware. With the presented model, the detection of the moving-target-skin-return in stationary objects under a noisy environment is feasible. Therefore, to track long range and high-speed objects, the proposed technique is promising. Using a scenario having 1) a target with 17 dBm2 radar cross section (RCS) at about 40 km range with 5.93 Mach speed and 11.6 dB post processing signal to noise ratio, and 2) a strong stationary clutter with 37 dBm2 RCS located at the proximity of the target, it demonstrates that the root-mean-square errors of range, angle and Doppler measurements are about 26 meters, 0.68 degree and 1100 Hz, respectively.

A Signal Processing Algorithm of Two-Phase Staggered PRI and Slow Time Signal Integration for MTI Triangular FMCW Multi-Target Tracking Radars

“…In the FMCW context, PRI also refers to the period of the waveform. In [ 27 ], we also observe the blind speed phenomenon with the triangular FMCW waveform and MTI.…”

“…In some cases, the open loop tracking radar system performs the dual function of both searching and tracking. The closed loop tracking schemes, which are seen in [ 24 , 25 , 26 , 27 ], require initial input parameters, such as the initial range, the initial 2D angles and the initial Doppler of an intended target, to establish a track. After establishing the track, the closed loop tracking radar relies on its signal processing to track the target.…”

“…After establishing the track, the closed loop tracking radar relies on its signal processing to track the target. In [ 27 ], an FMCW target-tracking radar is proposed and closed loop tracking of the target range and angles is applied to this system. This FMCW radar uses a constant false alarm rate (CFAR) detector [ 28 , 29 ] and 2D monopulse angle tracking [ 30 , 31 ].…”

“…The other main novelty of this paper is that we combine the staggered PRI scheme and the slow time signal integration scheme, which can achieve an extra processing gain of 4.77 dB in the blind speed region in the Doppler domain. The proposed algorithm improves the tracking performance of the algorithm in [ 27 ] in the radar blind speed zone. It can be seamlessly integrated with the range extrapolation method proposed in [ 27 ] to further improve the target tracking performance.…”

“…The proposed algorithm improves the tracking performance of the algorithm in [ 27 ] in the radar blind speed zone. It can be seamlessly integrated with the range extrapolation method proposed in [ 27 ] to further improve the target tracking performance.…”