Translational motion compensation of ballistic target based on radon transform
Ballistic target translational motion compensation is beneficial to motion parameter extraction. Aiming at the problem of multiple scattering points translational motion compensation, an algorithm is proposed to extract the translational motion parameters of ballistic targets based on using the projection transform of the whole micro-frequency curve by Radon transform in this paper. First, establishing and analyzing the typical ballistic target model and the expressions of scattering points' micro-frequency are solved. Second, target signal is pre-compensated based on radar information and time-frequency transform. And Radon transform is applied to the parameter projection of time-frequency curve. Then translational motion parameters are estimated based on minimum entropy criteria and gauss fitting. Finally, translational motion is compensated by making use of the estimated motion parameters. Simulation results verify the validity of the proposed algorithm.
Key parameter estimation for radar rotating object imaging with multi-aspect observations
Rotating object model is commonly used for imaging analysis in high resolution radars such as the inverse synthetic aperture radar (ISAR). For a rotating object, it is known that multi-aspect observations can improve cross-range resolution with the known imaging geometry. For the non-cooperative rotating object with unknown imaging geometry, this paper proposes an integrated scheme to estimate the key parameters, e.g., the rotating velocity and the aspect angle difference between every two observations. Furthermore, convolution back-projection (CBP) method is applied to provide fused imaging result with improved resolution. Also, the accuracy of the ultimate parameter estimation is analyzed, which is strongly related with several important factors like position extraction error of scattering centers and so on. Finally, the results of numerical experiments are provided to demonstrate the effectiveness of the proposed method.
Through-the-Wall Micro-Doppler Signatures
Radar technology has been utilized for through-the-wall operation in recent years. Through-the-wall radars have become an area of interest due to their usefulness in surveillance, search and rescue operations, and others. We address the specific challenges that through-the-wall radars endure, and present simulations and experimental data for through-the-wall micro-Doppler signatures. The design considerations, including wall attenuation, frequency selection, and dispersion are discussed. Some commonly used time-frequency transforms are briefly discussed with a focus on how they can be used to analyze micro-Doppler signatures. Some of the effects that a barrier such as a wall has on the return microDoppler signals and discusses how these differ from that of micro-Doppler signals that arise without any barrier are demonstrated. Some experimental data of micro-Doppler signatures for targets with and without a translational motion are presented. Some models of common human activities and motions are also discussed and compared to the experimentally measured through-the-wall micro-Doppler signals.