Adaptive Waveform Design with Multipath Exploitation Radar in Heterogeneous Environments

The problem of detecting point like targets over a glistening surface is investigated in this manuscript, and the design of an optimal waveform through a two-step process for a multipath exploitation radar is proposed. In the first step, a non-adaptive waveform is transmitted and a constrained Generalized Likelihood Ratio Test (GLRT) detector is deduced at reception which exploits multipath returns in the range cell under test by modelling the target echo as a superposition of the direct plus the multipath returns. Under the hypothesis of heterogeneous environments, thus by assuming a compound-Gaussian distribution for the clutter return, this latter is estimated in the range cell under test through the secondary data, which are collected from the out-of-bin cells. The Fixed Point Estimate (FPE) algorithm is applied in the clutter estimation, then used to design the adaptive waveform for transmission in the second step of the algorithm, in order to suppress the clutter coming from the adjacent cells. The proposed GLRT is also used at the end of the second transmission for the final decision. Extensive performance evaluation of the proposed detector and adaptive waveform for various multipath scenarios is presented. The performance analysis prove that the proposed method improves the Signal-to-Clutter Ratio (SCR) of the received signal, and the detection performance with multipath exploitation

A Two-Step Process for a Cognitive Radar Waveform Design with Multipath Exploitation

7th IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace) (2020 : Virtual, Online; Italy)In this paper, a two-step model is proposed, to design an optimal radar waveform to improve the detection of point like targets over a glistening surface. In this respect, a non adaptive waveform is first transmitted and a constrained Generalized Likelihood Ratio Test (GLRT) detector is used at the receiver, which exploits multipath returns in the range cell under test, by modelling the target echo as a superposition of the direct plus the multipath returns. Besides, the clutter returns are assumed to be compound-Gaussian. The Fixed Point Estimate (FPE) algorithm is used in order to estimate the clutter in the range cell under test through the secondary data collected from the out-of-bin cells. The clutter estimates are used to design an adaptive waveform for the next transmission, in order to suppress the clutter coming from adjacent cells. The proposed GLRT is also used at the end of the second transmission for the final decision. The performance analysis results show that the proposed algorithm increases the Signal-to-Clutter Ratio (SCR) of the received signal

Adaptive Waveform Design with Multipath Exploitation Radar in Heterogeneous Environments

The problem of detecting point like targets over a glistening surface is investigated in this manuscript, and the design of an optimal waveform through a two-step process for a multipath exploitation radar is proposed. In the first step, a non-adaptive waveform is transmitted and a constrained Generalized Likelihood Ratio Test (GLRT) detector is deduced at reception which exploits multipath returns in the range cell under test by modelling the target echo as a superposition of the direct plus the multipath returns. Under the hypothesis of heterogeneous environments, thus by assuming a compound-Gaussian distribution for the clutter return, this latter is estimated in the range cell under test through the secondary data, which are collected from the out-of-bin cells. The Fixed Point Estimate (FPE) algorithm is applied in the clutter estimation, then used to design the adaptive waveform for transmission in the second step of the algorithm, in order to suppress the clutter coming from the adjacent cells. The proposed GLRT is also used at the end of the second transmission for the final decision. Extensive performance evaluation of the proposed detector and adaptive waveform for various multipath scenarios is presented. The performance analysis prove that the proposed method improves the Signal-to-Clutter Ratio (SCR) of the received signal, and the detection performance with multipath exploitation

Multipath exploitation radar with adaptive detection in partially homogeneous environments

The authors deal with the problem of detecting point-like targets in the presence of diffuse multipath under the assumption of a partially homogeneous Gaussian disturbance by introducing an unknown scaling factor which represents the mismatch between the noise contribution of the cell under test and the training samples. Also, they model the target echo as a superposition of direct plus multipath components where multipath returns are thought of as scattered signals from a glistening surface. Hence, multipath echoes are represented as a Gaussian distributed random vector with an unknown covariance matrix. Then, the authors derive a constrained generalised likelihood ratio test under the assumption that the primary data covariance structure is similar to the covariance matrix obtained from training samples where the degree of similarity is up to both noise scaling factor and multipath contribution. Besides, they prove that the proposed detector ensures constant false alarm rate (CFAR) property with respect to the unknown parameters. Finally, they compared the devised algorithm with the commonly used CFAR estimators. The results show that the proposed detector copes well with diffuse multipath conditions under partially homogeneous environments