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Design of Doppler Resilient Sequences and Receiving Filters Against Interrupted-Sampling Repeater Jamming for Simultaneously Polarimetric Radars 为同时偏振雷达设计抗多普勒序列和接收滤波器以对抗中断采样中继器干扰
Pub Date : 2024-06-28 DOI: 10.1109/TRS.2024.3420551
Nanjun Li;Fulai Wang;Chen Pang;Yongzhen Li
Aimed to enhance the robustness of simultaneously polarimetric radar (SPR) systems against interrupted-sampling repeater jamming (ISRJ) attacks by polarization and waveform diversity techniques, this article focuses on the joint design of unimodular sequences and receiving filters for jamming suppression. Specifically, we first develop a dynamic signal processing framework for target polarization scattering matrix (PSM) estimation based on their statistical properties and orthogonal conditions between receiving filters and ISRJ signals. Then, the weighted sum of integrated sidelobe levels (ISLs) of auto- and cross-ambiguity functions and signal-to-noise ratio losses (SNRLs) is minimized with unimodular and energy constraints to mitigate ISRJ in SPR systems considering both single pulse and multipulse. To handle the resulting NP-hard design problems, an iterative optimization method capitalizing on the alternating direction and majorization-minimization (MM) framework is proposed. The numerical results are provided to show the superiority of the proposed algorithm in comparison with a pair of linear frequency modulation (LFM) waveforms with opposite slopes with respect to the anti-ISRJ performance.
为了利用极化和波形分集技术增强同时极化雷达(SPR)系统对中断采样中继器干扰(ISRJ)攻击的鲁棒性,本文重点讨论了抑制干扰的单模态序列和接收滤波器的联合设计。具体来说,我们首先根据目标极化散射矩阵(PSM)的统计特性以及接收滤波器和 ISRJ 信号之间的正交条件,为目标极化散射矩阵(PSM)估计开发了一个动态信号处理框架。然后,考虑到单脉冲和多脉冲,在单模态和能量约束条件下最小化自模糊函数和交叉模糊函数的集成侧叶电平(ISL)和信噪比损失(SNRL)的加权和,以减轻 SPR 系统中的 ISRJ。为了处理由此产生的 NP 难设计问题,提出了一种利用交替方向和大化-最小化(MM)框架的迭代优化方法。数值结果表明,与一对斜率相反的线性频率调制(LFM)波形相比,所提出的算法在抗 ISRJ 性能方面更具优势。
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引用次数: 0
Photonics-Based Broadband Single-Input-Multiple- Output-OAM Coincidence Imaging 基于光子学的宽带单输入多输出-OAM 重合成像技术
Pub Date : 2024-06-24 DOI: 10.1109/TRS.2024.3418461
Guanqun Sun;Fangzheng Zhang;Xiaoyue Yu;Yuewen Zhou;Yuhui He;Xing Wang;Shilong Pan
A photonics-based broadband single-input-multiple-output (SIMO)-orbital angular momentum (OAM) radar is proposed to implement high-resolution radar imaging. In the transmitter, a broadband linear frequency-modulated (LFM) signal is generated by an optically injected semiconductor laser and emitted by a single antenna to illuminate the target. In the receiver, a uniform circular array (UCA) collects the echoes and introduces OAM modulations before photonic frequency mixing is implemented for broadband dechirp processing. The use of microwave photonic techniques enlarges the operation bandwidth and thus improves the radar range resolution, while the SIMO structure mitigates the OAM beam divergence and energy hollow problems. Based on this SIMO-OAM radar, a super-resolution imaging method with random OAM modulation and coincidence processing is proposed to break through the azimuth resolution limitation. A proof-of-concept photonics-based $1times 16$ OAM radar is established with an 8-GHz (18–26 GHz) bandwidth, of which the range resolution reaches 2.1 cm. By using the proposed imaging method, super-resolution imaging with six times higher azimuth resolution than traditional OAM radar is achieved. In the experiment, high-resolution imaging of small-size complex targets is successfully demonstrated, verifying that the proposed system and imaging method can meet the requirement for high-resolution radar detection and high-precision target recognition.
为实现高分辨率雷达成像,提出了一种基于光子学的宽带单输入多输出(SIMO)轨道角动量(OAM)雷达。在发射器中,宽带线性频率调制(LFM)信号由光注入半导体激光器产生,并由单根天线发射以照亮目标。在接收器中,均匀圆形阵列(UCA)收集回波并引入 OAM 调制,然后进行光子混频以实现宽带去啁啾处理。微波光子技术的使用扩大了工作带宽,从而提高了雷达的测距分辨率,而 SIMO 结构则减轻了 OAM 波束发散和能量中空问题。在这种 SIMO-OAM 雷达的基础上,提出了一种采用随机 OAM 调制和巧合处理的超分辨率成像方法,以突破方位分辨率的限制。建立了一个基于光子技术的1美元/次16美元OAM雷达概念验证,带宽为8千兆赫(18-26千兆赫),其测距分辨率达到2.1厘米。通过使用所提出的成像方法,实现了超分辨率成像,其方位角分辨率是传统 OAM 雷达的六倍。在实验中,成功演示了小尺寸复杂目标的高分辨率成像,验证了所提出的系统和成像方法能够满足高分辨率雷达探测和高精度目标识别的要求。
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引用次数: 0
High-Resolution Polarimetric Radar for Autonomous Vehicle Research at W-Band Frequencies 用于 W 波段频率自主车辆研究的高分辨率测偏振雷达
Pub Date : 2024-06-24 DOI: 10.1109/TRS.2024.3418689
Adib Y. Nashashibi;Tanner J. Douglas;Mani Kashanianfard;Stephen W. Decker;Kamal Sarabandi
This article presents a fully polarimetric instrumentation radar designed for conducting phenomenological studies in support of autonomous vehicle research at W-band frequencies. The compact radar utilizes a unique single-antenna system with a narrow beamwidth of 1.1° (two-way) and better than 45-dB isolation between the transmit and receive signal paths. It employs the frequency-modulated continuous-wave (FMCW) modulation scheme and operates over a maximum bandwidth of 5.5 GHz centered around 79.25 GHz. The radar benefits from a low phase noise level of −86 dBc/Hz at 10-kHz offset and its receiver channels have an effective noise figure value of 2.7 dB. The calibrated radar can be used to accurately measure the polarimetric response of both point and distributed targets. It can also generate high-resolution range-velocity maps of moving targets in a given traffic scene. The radar was used to characterize the polarimetric response of slow-moving targets, such as pedestrians and bicycles. The statistics of the radar cross sections (RCSs) of these targets were computed, and unique features observed in the range-velocity maps of these targets were revealed.
本文介绍了一种全偏振测量仪器雷达,设计用于在 W 波段频率上进行现象学研究,以支持自动驾驶汽车研究。该雷达结构紧凑,采用独特的单天线系统,波束宽度窄至 1.1°(双向),发射和接收信号路径之间的隔离度优于 45 分贝。它采用频率调制连续波(FMCW)调制方案,最大带宽为 5.5 GHz,中心频率为 79.25 GHz。该雷达在 10 千赫偏移时的相位噪声水平低至 -86 dBc/Hz,其接收器通道的有效噪声系数值为 2.7 dB。经过校准的雷达可用于精确测量点目标和分布式目标的偏振响应。它还可以生成给定交通场景中移动目标的高分辨率测距速度图。该雷达用于描述行人和自行车等慢速移动目标的极化响应特征。对这些目标的雷达截面(RCS)进行了统计计算,并揭示了在这些目标的测距速度图中观察到的独特特征。
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引用次数: 0
Quantitative Microwave Imaging Using Deep Learning Network Guided by Plane Wave Equation 利用平面波方程引导的深度学习网络进行微波定量成像
Pub Date : 2024-06-21 DOI: 10.1109/TRS.2024.3417519
Rahul Sharma;Okan Yurduseven
Accurately characterizing material properties, particularly the spatial distribution of permittivity, is crucial across diverse domains such as medical imaging, nondestructive testing, and materials science. This work introduces an innovative strategy to tackle the inverse problem of deducing the permittivity distribution within a medium by leveraging time-dependent data of the electric field distribution. The approach utilizes a neural network trained with guidance from the wave equation, embedding the fundamental physics of wave propagation within the network architecture. This integration empowers the network to assimilate domain-specific knowledge during training, combining deep learning capabilities with physics-based constraints. This hybrid framework establishes a robust relationship between the time changing electric field distribution and the underlying permittivity distribution, effectively solving the complex inverse problem. By training on a comprehensive dataset, the neural network discerns intricate variations in spatial permittivity from the intricate temporal evolution of the electric field. Results validate the effectiveness of this approach, showcasing impressive accuracy in the reconstruction of the permittivity distribution.
准确表征材料特性,尤其是介电常数的空间分布,在医学成像、无损检测和材料科学等多个领域都至关重要。这项研究引入了一种创新策略,利用随时间变化的电场分布数据,解决推导介质中介电常数分布的逆问题。该方法利用神经网络,在波方程的指导下进行训练,将波传播的基本物理学原理嵌入网络架构中。这种整合使网络能够在训练过程中吸收特定领域的知识,将深度学习能力与基于物理学的约束相结合。这种混合框架在随时间变化的电场分布和底层介电常数分布之间建立了稳健的关系,从而有效地解决了复杂的逆问题。通过在综合数据集上进行训练,神经网络能从电场错综复杂的时间演化中分辨出空间介电常数的复杂变化。结果验证了这一方法的有效性,展示了在重构介电常数分布方面令人印象深刻的准确性。
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引用次数: 0
Discovering the Unseen: Radar-Based Estimation of Heartbeat, Breathing Rate, and Underlying Muscle Expansion Without Probes 发现未知:基于雷达的心跳、呼吸频率和底层肌肉膨胀估算(无需探头
Pub Date : 2024-06-11 DOI: 10.1109/TRS.2024.3412915
Sajid Ahmed;Pratiti Paul;Tharmalingam Ratnarajah;Mohamed-Slim Alouini
Effective monitoring of vital signs is a fundamental aspect of healthcare. To measure vital signs, patients often hesitate to wear probes and body-worn sensors for extended periods because these devices can limit their movement and cause discomfort. In this study, we present three radar-based techniques to estimate vital signs and underlying muscle expansion. The first method employs a short-time Fourier transform (STFT), but it has limitations due to its fixed resolution and its performance dependency on the carrier frequency. The second method modifies the Hilbert-Huang transform (HHT) to address the mode-mixing problem. The HHT breaks down the signal into its fundamental components. By subsequently applying Fourier transform and signal filtering, we demonstrate its feasibility of estimating heartbeat and breathing rates. In our latest method, which constitutes the primary contribution of this study, we exploit the repetitive patterns inherent in both heartbeat and breathing signals. This involves representing the spectrum of the received signal as a discrete frequency spectrum and subsequently applying harmonic accumulation. Our simulation results consistently demonstrate that the harmonics accumulation (HA) algorithm outperforms other algorithms in terms of accuracy and effectiveness. To assess the performance of our suggested algorithms, we derive the Cramér-Rao lower bound (CRLB) as a benchmark. Our results show the effectiveness of the proposed methods.
有效监测生命体征是医疗保健的一个基本方面。为了测量生命体征,患者往往不愿意长时间佩戴探针和体戴式传感器,因为这些设备会限制他们的活动并造成不适。在这项研究中,我们提出了三种基于雷达的技术来估计生命体征和潜在的肌肉膨胀。第一种方法采用短时傅立叶变换 (STFT),但由于其分辨率固定且性能取决于载波频率,因此存在局限性。第二种方法修改了希尔伯特-黄变换(HHT),以解决模式混合问题。HHT 将信号分解为基本分量。通过随后的傅里叶变换和信号滤波,我们证明了其估算心跳和呼吸频率的可行性。在我们的最新方法中,我们利用了心跳和呼吸信号中固有的重复模式,这是本研究的主要贡献。这包括将接收信号的频谱表示为离散频谱,然后应用谐波累加。我们的模拟结果一致表明,谐波累积(HA)算法在准确性和有效性方面优于其他算法。为了评估所建议算法的性能,我们推导出了克拉梅尔-拉奥下限(CRLB)作为基准。我们的结果表明了建议方法的有效性。
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引用次数: 0
Concept Evaluation of a DDFS and RFDAC-Based FMCW Modulator 基于 DDFS 和 RFDAC 的 FMCW 调制器概念评估
Pub Date : 2024-06-05 DOI: 10.1109/TRS.2024.3410137
Soumya Krishnapuram Sireesh;Niels Christoffers;Christoph Wagner;Andreas Stelzer
This article describes a method of deriving and verifying hardware specification of a direct digital frequency synthesizer (DDFS) and radio frequency digital-to-analog converter (RFDAC)-based frequency-modulated continuous-wave (FMCW) modulator. The analysis of the concept is conducted by studying the digital nonlinearities, such as amplitude quantization noise, phase quantization noise, and frequency error in the ramp, and analog nonlinearities, such as IQ quadrature error and counter inter modulation-3 (CIM3) of the RFDAC. The impact of the nonlinearities on the detectability of target in the intermediate frequency (IF) spectrum is evaluated with the MATLAB model of the frequency modulator. The outcome of the concept evaluation predicts the low-level hardware specifications needed for the design such as amplitude quantization, phase quantization, expected noise level, spur positions in the target IF spectrum, and frequency error in the ramp. The RFDAC-based FMCW modulator is manufactured in 28-nm technology with the derived parameters and the time-domain data of a frequency ramp from 5 to 9-GHz in 100 $mu $ s is sampled during measurement. The data are postprocessed to confirm the predictions made by the simulation model and to characterize ramp linearity, dynamic phase noise (DPN), and settling time of the ramp. The frequency error for a 4-GHz ramp in 100- $mu $ s duration is ±100kHz, and the settling time in the postprocessed result is in the 20-ns range.
本文介绍了一种推导和验证基于直接数字频率合成器(DDFS)和射频数模转换器(RFDAC)的频率调制连续波(FMCW)调制器硬件规格的方法。通过研究数字非线性因素(如幅度量化噪声、相位量化噪声和斜坡中的频率误差)和模拟非线性因素(如 RFDAC 的 IQ 正交误差和计数器间调制-3 (CIM3)),对这一概念进行了分析。利用频率调制器的 MATLAB 模型评估了非线性因素对中频 (IF) 频谱中目标可探测性的影响。概念评估结果预测了设计所需的低级硬件规格,如幅度量化、相位量化、预期噪声水平、目标中频频谱中的杂散位置以及斜坡中的频率误差。基于 RFDAC 的 FMCW 调制器是用 28 纳米技术制造的,采用了推导出的参数,并在测量过程中采样了 100 美元/毫秒内从 5 GHz 到 9 GHz 频率斜坡的时域数据。对数据进行后处理,以确认仿真模型的预测结果,并确定斜坡线性度、动态相位噪声 (DPN) 和斜坡稳定时间。持续时间为 100- $mu $ s 的 4 GHz 斜坡的频率误差为 ±100kHz,后处理结果中的沉降时间在 20-ns 范围内。
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引用次数: 0
Constant Modulus Precoded MIMO Radar Based on Zadoff-Chu Sequences 基于 Zadoff-Chu 序列的恒定模数预编码 MIMO 雷达
Pub Date : 2024-06-03 DOI: 10.1109/TRS.2024.3409029
Matthew G. Gaydos;David J. Love;Taejoon Kim
Multiple-input-multiple-output (MIMO) radar systems have become a heavily researched topic in recent years due to the improved diversity techniques when compared to that of 1-D radar waveforms. Although there exist a myriad of techniques to design the transmit power distribution for MIMO radar systems, stringent constant modulus power limitations imposed by modern high-power amplifiers (HPAs) complicate their practical implementation. Ideally, a technique that emulates the spatial filtering flexibility of precoded MIMO communications is desired. To achieve such flexibility, an MIMO radar framework must be introduced that guarantees constant modulus for all combinations of signal sets and precoders, allowing simple interchangeability between components of the waveform—whether that be a new transmit power distribution or an adjusted dynamic MIMO radar waveform. In this article, we show that designing a constant modulus precoded MIMO radar can be achieved in a practical manner, utilizing alphabet-based waveform construction. This technique leverages the use of two sets for which the product of any pair of vectors, one from each alphabet, guarantees a fixed constant. By utilizing these sets as alphabets to design the waveform, it is possible to implement MIMO radar waveforms of any rank and enable the decoupling of the precoder and MIMO radar waveform design. This article presents a framework that achieves the aforementioned requirements by utilizing the properties of Zadoff-Chu (ZC) sequences and the discrete Fourier transform (DFT) matrix. By restricting construction of the precoder and signal set to be in part formed from finite alphabets, it is shown that the constant modulus constraint is achieved for any precoder and any signal set combination.
与一维雷达波形相比,多输入多输出(MIMO)雷达系统改进了分集技术,因此成为近年来研究的热点。虽然有无数种技术可用于设计 MIMO 雷达系统的发射功率分布,但现代大功率放大器(HPA)施加的严格恒定模数功率限制使其实际应用变得复杂。理想情况下,我们需要一种技术来模拟预编码多输入多输出通信的空间滤波灵活性。要实现这种灵活性,必须引入一种 MIMO 雷达框架,它能保证信号集和预编码器的所有组合都具有恒定的模数,并允许波形各组成部分之间的简单互换--无论是新的发射功率分布还是调整后的动态 MIMO 雷达波形。在本文中,我们将展示如何利用基于字母的波形构造,以实用的方式设计恒定模预编码 MIMO 雷达。这种技术利用了两个集合,其中任何一对矢量的乘积(来自每个字母表的一个矢量)都能保证一个固定常数。利用这些集合作为字母表来设计波形,就有可能实现任何等级的 MIMO 雷达波形,并实现前置编码器和 MIMO 雷达波形设计的解耦。本文提出了一个框架,利用扎多夫-楚(ZC)序列和离散傅立叶变换(DFT)矩阵的特性来实现上述要求。通过限制前置编码器和信号集的构造部分由有限字母组成,证明了恒定模数约束可在任何前置编码器和任何信号集组合中实现。
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引用次数: 0
An Efficient Approach for Calibration of Automotive Radar–Camera With Real-Time Projection of Multimodal Data 利用多模态数据实时投影校准汽车雷达相机的高效方法
Pub Date : 2024-06-03 DOI: 10.1109/TRS.2024.3408231
Nitish Kumar;Ayush Dasgupta;Venkata Satyanand Mutnuri;Rajalakshmi Pachamuthu
This article presents a comprehensive method for radar-camera calibration with a primary focus on real-time projection, addressing the critical need for precise spatial and temporal alignment between radar and camera sensor modalities. The research introduces a novel methodology for calibration utilizing geometrical transformation, incorporating radar corner reflectors to establish correspondences. This methodology applies to post-automotive manufacturing for integration into radar-camera applications such as advanced driver-assistance systems (ADASs), adaptive cruise control (ACC), collision warning, and mitigation systems. It also serves post-production for sensor installation and algorithm development. The proposed approach employs an advanced algorithm to optimize spatial and temporal synchronization and radar and camera data alignment, ensuring accuracy in multimodal sensor fusion. Rigorous validation through extensive testing demonstrates the efficiency and reliability of the proposed system. The results show that the calibration method is highly accurate compared to the existing state-of-the-art methods, with minimal errors, an average Euclidean distance (AED) of 1.447, and a root-mean-square reprojection error (RMSRE) of (0.1720, 0.5965), indicating a highly efficient spatial synchronization method. During real-time projection, the proposed algorithm for temporal synchronization achieves an average latency of 35 ms between frames.
本文介绍了一种全面的雷达-照相机校准方法,主要侧重于实时投影,解决了雷达和照相机传感器模式之间精确空间和时间对准的关键需求。研究介绍了一种利用几何变换进行校准的新方法,结合雷达角反射器建立对应关系。该方法适用于汽车后期制造,可集成到雷达-摄像头应用中,如高级驾驶辅助系统(ADAS)、自适应巡航控制(ACC)、碰撞预警和缓解系统。它还可用于传感器安装和算法开发的后期生产。所提出的方法采用了先进的算法来优化空间和时间同步以及雷达和摄像头数据对齐,从而确保多模态传感器融合的准确性。通过大量测试进行的严格验证证明了所提系统的效率和可靠性。结果表明,与现有的先进方法相比,校准方法具有极高的准确性,误差极小,平均欧氏距离(AED)为 1.447,均方根重投影误差(RMSRE)为(0.1720,0.5965),表明这是一种高效的空间同步方法。在实时投影过程中,所提出的时间同步算法实现了帧与帧之间 35 毫秒的平均延迟。
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引用次数: 0
A Priority-Based Scheduling Scheme for Search, Track, and Communications in MPARs 基于优先级的 MPAR 搜索、跟踪和通信调度方案
Pub Date : 2024-04-29 DOI: 10.1109/TRS.2024.3394896
Augusto Aubry;Antonio De Maio;Luca Pallotta
The modern battlefield scenario is strongly influenced by the innovative capabilities of multifunction phased array radars (MPARs), which can perform a plethora of sensing and communication (COM) activities sequentially or in parallel. In fact, the MPAR can functionally cluster its phased array into bespoke subapertures implementing different tasks. Accordingly, a portion of the other available resources, e.g., bandwidth, power-aperture product (PAP), and time, is also assigned to each subaperture, and the grand challenge is the definition of strategies for optimal scheduling of the tasks to be executed. In this respect, a rule-based algorithm for task scheduling is proposed in this article. In a nutshell, in each time window, the procedure first allocates the radar tasks (viz., volume search, cued search, update, and confirmation tracking) and then utilizes the COM looks to fill the empty intraslot time left by the radar tasks. When there are two concurrent looks, the allocation is performed according to their priorities. Moreover, if the bandwidth and PAP are sufficient, some of them can be also scheduled in parallel. Interesting results in terms of bandwidth and time occupancy efficiency are observed from simulations conducted in challenging scenarios comprising also multiple maneuvering targets.
多功能相控阵雷达(MPAR)的创新能力对现代战场场景产生了重大影响,它可以连续或并行地执行大量传感和通信(COM)活动。事实上,MPAR 可以在功能上将其相控阵集群为执行不同任务的定制子孔径。因此,其他可用资源(如带宽、功率-孔径乘积(PAP)和时间)的一部分也被分配给每个子孔径,而最大的挑战在于如何定义待执行任务的优化调度策略。为此,本文提出了一种基于规则的任务调度算法。简而言之,在每个时间窗口中,该程序首先分配雷达任务(即体积搜索、提示搜索、更新和确认跟踪),然后利用 COM 观测来填补雷达任务留下的空隙内时间。当有两个并发观测任务时,将根据它们的优先级进行分配。此外,如果带宽和 PAP 足够,其中一些任务也可以并行调度。通过在具有挑战性的场景(包括多个机动目标)中进行模拟,在带宽和时间占用效率方面观察到了有趣的结果。
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引用次数: 0
Toward Land Vehicle Ego-Velocity Estimation Using Deep Learning and Automotive Radars 利用深度学习和汽车雷达实现陆地车辆自我速度估计
Pub Date : 2024-04-22 DOI: 10.1109/TRS.2024.3392439
Paulo Ricardo Marques de Araujo;Aboelmagd Noureldin;Sidney Givigi
This paper presents a deep learning framework for the estimation of land vehicle ego-velocity using Frequency Modulated Continuous Wave (FMCW) automotive radars, addressing the challenges of data sparsity and noise without the need for extrinsic radar calibration. By structuring radar scans into image-based and voxel-based networks, our approach demonstrates robust ego-velocity estimation across multiple sensor configurations and orientations. Experimental results from three distinct datasets—RadarScenes, NavINST, and MSC-RAD4R—validate the framework’s effectiveness, showing superior performance over traditional methods. The models’ adaptability to various sensor specifications and their computational efficiency highlight their potential for real-time applications. We made our implementation open-source at: https://github.com/paaraujo/deep-ego-velocity.
本文提出了一种利用频率调制连续波(FMCW)汽车雷达估算陆地车辆自我速度的深度学习框架,无需进行外部雷达校准即可解决数据稀疏性和噪声的挑战。通过将雷达扫描结构化为基于图像和基于体素的网络,我们的方法在多种传感器配置和方向上实现了稳健的自我速度估计。来自三个不同数据集(RadarScenes、NavINST 和 MSC-RAD4R)的实验结果验证了该框架的有效性,显示出优于传统方法的性能。模型对各种传感器规格的适应性及其计算效率凸显了其在实时应用中的潜力。我们将我们的实现开源于 https://github.com/paaraujo/deep-ego-velocity。
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引用次数: 0
期刊
IEEE Transactions on Radar Systems
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