In this advanced exploration, we focus on multiple parameters estimation in bistatic Multiple-Input Multiple-Output(MIMO) radar systems, a crucial technique for target localization and imaging. Our research innovative...In this advanced exploration, we focus on multiple parameters estimation in bistatic Multiple-Input Multiple-Output(MIMO) radar systems, a crucial technique for target localization and imaging. Our research innovatively addresses the joint estimation of the Direction of Departure(DOD), Direction of Arrival(DOA), and Doppler frequency for incoherent targets. We propose a novel approach that significantly reduces computational complexity by utilizing the TemporalSpatial Nested Sampling Model(TSNSM). Our methodology begins with a multi-linear mapping mechanism to efficiently eliminate unnecessary virtual Degrees of Freedom(DOFs) and reorganize the remaining ones. We then employ the Toeplitz matrix triple iteration reconstruction method, surpassing the traditional Temporal-Spatial Smoothing Window(TSSW) approach, to mitigate the single snapshot effect and reduce computational demands. We further refine the highdimensional ESPRIT algorithm for joint estimation of DOD, DOA, and Doppler frequency, eliminating the need for additional parameter pairing. Moreover, we meticulously derive the Cramér-Rao Bound(CRB) for the TSNSM. This signal model allows for a second expansion of DOFs in time and space domains, achieving high precision in target angle and Doppler frequency estimation with low computational complexity. Our adaptable algorithm is validated through simulations and is suitable for sparse array MIMO radars with various structures, ensuring higher precision in parameter estimation with less complexity burden.展开更多
To fulfill the requirements of high-precision common baseline measurement for multiple parameters,such as surface profiling and the curvature radius of large-aperture optical elements on the same instrument,this paper...To fulfill the requirements of high-precision common baseline measurement for multiple parameters,such as surface profiling and the curvature radius of large-aperture optical elements on the same instrument,this paper proposes a research on a high-precision large-aperture laser differential confocal-interferometric measurement method.This method is based on the principle of laser differential confocal combined with interferometry.It utilizes a Galilean double-reflection collimation system to generate well large-aperture collimated beams and employs mechanical phase-shifting technology for large-aperture and heavy-load reference lenses to overcome the flaws of existing large-aperture wavelength-tuning phase shifting technology in theory,thus achieving highprecision and high-stable phase-shifting interference in large-aperture surface profiling measurements.By utilizing the laser differential confocal method with anti-scattering and anti-interference properties,high-precision common baseline measurements are achieved for the multiple-parameter of optical elements such as ultra-long focal lengths and ultra-large curvature radii.The measurements of large-aperture surface profiles,the mean PV was 46.0 nm.For the ultra-long focal length,the relative standard deviation was 0.019%,whereas for the ultra-large curvature radius,the relative standard deviation was 0.0036%.This method enables high-precision,high-stable,and high-efficient common baseline measurements for the multiple parameters of optical elements with large,medium,and small apertures thereby providing an effective technical approach for improving the detection and machining precision of optical elements.展开更多
基金supported in part by the National Natural Science Foundation of China(No.62071476)in part by China Postdoctoral Science Foundation(No.2022M723879)in part by the Science and Technology Innovation Program of Hunan Province,China(No.2021RC3080)。
文摘In this advanced exploration, we focus on multiple parameters estimation in bistatic Multiple-Input Multiple-Output(MIMO) radar systems, a crucial technique for target localization and imaging. Our research innovatively addresses the joint estimation of the Direction of Departure(DOD), Direction of Arrival(DOA), and Doppler frequency for incoherent targets. We propose a novel approach that significantly reduces computational complexity by utilizing the TemporalSpatial Nested Sampling Model(TSNSM). Our methodology begins with a multi-linear mapping mechanism to efficiently eliminate unnecessary virtual Degrees of Freedom(DOFs) and reorganize the remaining ones. We then employ the Toeplitz matrix triple iteration reconstruction method, surpassing the traditional Temporal-Spatial Smoothing Window(TSSW) approach, to mitigate the single snapshot effect and reduce computational demands. We further refine the highdimensional ESPRIT algorithm for joint estimation of DOD, DOA, and Doppler frequency, eliminating the need for additional parameter pairing. Moreover, we meticulously derive the Cramér-Rao Bound(CRB) for the TSNSM. This signal model allows for a second expansion of DOFs in time and space domains, achieving high precision in target angle and Doppler frequency estimation with low computational complexity. Our adaptable algorithm is validated through simulations and is suitable for sparse array MIMO radars with various structures, ensuring higher precision in parameter estimation with less complexity burden.
基金supported by National Natural Science Foundation Joint Fund Integrated Project(No.U22A6006)National Key scientific research instrument Development Project of the National Natural Science Foundation of China(No.52327806).
文摘To fulfill the requirements of high-precision common baseline measurement for multiple parameters,such as surface profiling and the curvature radius of large-aperture optical elements on the same instrument,this paper proposes a research on a high-precision large-aperture laser differential confocal-interferometric measurement method.This method is based on the principle of laser differential confocal combined with interferometry.It utilizes a Galilean double-reflection collimation system to generate well large-aperture collimated beams and employs mechanical phase-shifting technology for large-aperture and heavy-load reference lenses to overcome the flaws of existing large-aperture wavelength-tuning phase shifting technology in theory,thus achieving highprecision and high-stable phase-shifting interference in large-aperture surface profiling measurements.By utilizing the laser differential confocal method with anti-scattering and anti-interference properties,high-precision common baseline measurements are achieved for the multiple-parameter of optical elements such as ultra-long focal lengths and ultra-large curvature radii.The measurements of large-aperture surface profiles,the mean PV was 46.0 nm.For the ultra-long focal length,the relative standard deviation was 0.019%,whereas for the ultra-large curvature radius,the relative standard deviation was 0.0036%.This method enables high-precision,high-stable,and high-efficient common baseline measurements for the multiple parameters of optical elements with large,medium,and small apertures thereby providing an effective technical approach for improving the detection and machining precision of optical elements.
