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一种简易的激光测距能力检测方法的研究 总被引:2,自引:0,他引:2
介绍了一种简单易行的激光测距能力检测方法。该方法是根据测距方程,结合外场已
知目标和气象条件,使目标的探测功率与设备要求的最小探测功率相等,由此求出对应的接收面积,用此面积对已知目标进行测距,当测距回波率满足要求时,确定设备的测距能力达到要求,通过外场应用证明该方法切实可行。 相似文献
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测距精度决定了二次雷达系统的目标分辨能力。针对现有二次雷达测距算法测距精度低的问题,分析了二次雷达的测距原理和引入的误差,提出了改进的自适应测距方法。在不更改二次雷达信号格式和硬件设计的前提下,采用分布式处理方式,使询问机和应答机能自动周期性测试本机内部延时,并在询问应答过程中自动分别扣除本设备的内部延时,从而提高二次雷达系统的测距精度。 相似文献
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针对超声波测距方法中的相位检测法检测范围有限、声波幅值检测法易受反射介质和不同反射面影响的问题,提出了通过测量超声波往返时间进行测距的方法。在对该方法工作原理进行简要介绍的基础上,设计了一种基于AT89C2051型单片机控制的超声波测距系统的硬件电路和软件控制程序,并对测试数据进行了分析。实验结果表明,该系统运行正常,测距范围和测量精度均可满足大多数场合的非接触式短距离测距要求。 相似文献
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在自动驾驶场景下,为了实现对智能车辆前方障碍物进行目标检测及测距,提出了一种基于单目视觉的前方车辆及行人检测与测距方法.利用数据集对YOLOv3神经网络模型进行优化训练,利用训练完成的神经网络对实时采集的视频信号中的车辆及行人进行目标检测,输出车辆及行人目标的检测框.以目标检测框底部中心点为参考点,根据相似三角形测距算... 相似文献
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基于雷达宽带回波的目标测距和测速方法 总被引:2,自引:0,他引:2
目标特性测量雷达一般采用宽窄带交替的工作方式,宽带用于获得目标高分辨特征信息,窄带用于目标检测和跟踪.如果雷达只采用宽带工作方式就能够既进行目标检测和跟踪,又能获得目标高分辨特征,则可以降低雷达系统的复杂性,并节约雷达的时间能量.文中提出了一种基于雷达宽带回波的目标测昔方法,该方法利用多个宽带回波的幅度和相位信息测苗目标距离和速度,实际数据的实验结果验证了该方法具有较高的测距和测速精度. 相似文献
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地面目标的红外被动测距研究 总被引:9,自引:3,他引:6
讨论了地面目标与背景红外辐射在大气中的传输情况,基于红外探测系统测出的目标与背景的辐照度差,提出了一种新的被动测距方法.利用该方法,得到了测距公式和测距的距离分辨率公式.计算了不同天气情况下,目标与背景的辐照度差与距离以及距离分辨率与距离之间的关系.计算结果表明,该方法可用于对地面目标的被动测距. 相似文献
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双目立体实时测距系统的关键技术研究 总被引:7,自引:0,他引:7
基于双目视差测距原理,建立了一个被动测距实验系统。围绕提高测距系统的测距精
度、准确率、速度和抗干扰性能等,研究了图像预处理、配准算法、搜索策略等关键技术。提出了改进的互积相关配准测度,并采用粗、精配准相结合的搜索策略以及抛物线拟合方法,实现了快速双目立体目标测距。实验证明该测距算法可有效地抑止噪声、双目光强和图像对比度差异等因素的影响;测距系统测距精度高、稳定性好、实时性好,对于10km目标相对测距误差小于4% ,响应时间小于0. 5 s。 相似文献
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为全面评价激光定距引信的探测能力,确定其随距离变化的规律,通过推导脉冲激光测距回波方程,建立脉冲激光测距数据分布解析方程并提出误差量化评价方法。仿真分析并评估了探测距离对回波信号及探测能力各指标的影响,最后通过试验得到验证。结果表明:可靠测程内,引信可实现可靠探测,随探测距离减小,测距随机误差先减小后增加,系统误差逐渐增加;引信最大可靠测程为84.8 m,测程内随机误差为0.22~0.73 m,满足引信远程定距的需求;提高阈值可明显改善测距误差,但会造成可靠测程减小。所得探测能力变化规律与评价方法可为脉冲激光引信设计与应用提供理论依据。 相似文献
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An amplitude calibration method for a terahertz time-domain spectroscopy system (THz-TDS) is proposed and demonstrated for transmittance measurement. The method is based on a direct comparison method using a terahertz attenuator as a reference standard. The measurement uncertainties of the THz-TDS are evaluated in transmittance measurements of metalized film attenuators as test samples. The relative expanded uncertainty is found to be 6.4–14.0% (k = 2) at 1 THz for transmittances ranging from 1 to 0.001. In addition, the calibration capability is extended to the available frequency range of the THz-TDS by considering spectral flatness of the reference standard. Validations of the method are also conducted by comparing the measurements between different systems, and it is confirmed that they agree well with each other. 相似文献
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脉冲激光测距精度是影响二维激光扫描成像质量的重要因素,研究近距离条件下收发同轴系统中的脉冲激光测距技术对提高二维激光扫描成像质量具有重要意义。通过仿真计算分析了脉冲激光测距的精度与回波能量的关系,提出了二维激光扫描成像光学系统的基本设计方案。在室内距离下,提出了在收发同轴光学系统中,到达探测器的激光回波能量相对于距离的非线性关系,计算并得到了激光回波能量相对于距离的非线性关系曲线。最后,基于实测数据对激光回波能量与距离的非线性关系进行实验验证,分析该非线性关系对激光测距精度的影响。论文的研究对设计、完善近距离条件下激光测距光学系统具有重要价值。 相似文献
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John Scott Parker Pascal Mickelson Jeremy Yeak Kevin Kremeyer Jason Rife 《Journal of Infrared, Millimeter and Terahertz Waves》2016,37(10):1021-1042
This paper demonstrates the feasibility of GPS-like ranging at terahertz (THz) frequencies. It is well established that GPS carrier signals are vulnerable to jamming via radio-frequency interference (RFI). As a result, there is a need for alternative radionavigation systems. THz signals offer a compelling option. Because of their high frequency (roughly ×100 higher than GPS), THz signals can be used to make highly precise range measurements. In addition, the large separation between the GPS and THz frequencies means that interference at GPS frequencies is very unlikely to impact the THz band. This paper lays the groundwork for a GPS-like ranging capability at THz frequencies. To this end, we identify key differences between THz hardware and GPS (radio frequency) hardware; we experimentally evaluate performance of a 0.30-THz system on a compact outdoor test range, and we introduce a measurement error model that highlights the distinctive role that multipath interference plays at THz frequencies. 相似文献
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本文直接采用模拟测距的消光比测试方法来检测脉冲激光测距仪的灵敏度,可以有效地排除远距离测距中气象差异的影响和地形条件的限制。通过对测试数据的分析并与测距能力相比较表明,本文提出的检测方法是有效的。 相似文献
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An Efficient Method of Eliminating the Range Ambiguity for a Low-Cost FMCW Radar Using VCO Tuning Characteristics 总被引:1,自引:0,他引:1
《Microwave Theory and Techniques》2006,54(10):3623-3629
This paper describes a simple method of eliminating the range ambiguity and the design approach for low-cost and small-size homodyne frequency-modulated continuous-wave (FMCW) radars. The range measurement accuracy could be efficiently improved by proper time gating of the beat signal without any closed-loop linearity compensation circuitry for typical varactor-tuned voltage-controlled oscillators (VCOs). The presented selectively gated fast Fourier transformation method is immune to the frequency shift of the VCOs. A$W$ -band FMCW radar using a raw varactor-tuned VCO having the percent linearity of 7.16% was implemented, and achieved less than 2% ranging error of the target lying at 200 m. Owing to the simple structure and fast processing speed, this method is applicable to the various low-cost radar sensors for ranging and detection. 相似文献
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Stereoscopic Passive Millimeter-Wave Imaging and Ranging 总被引:4,自引:0,他引:4
《Microwave Theory and Techniques》2005,53(8):2594-2599
This paper presents the first stereoscopic range measurements at a wavelength of 3.3 mm and discusses the accuracy of this new method. The synthesis of passive millimeter-wave imaging and stereoscopy combines the advantages of both principles, naturally looking high-contrast images and superior poor-weather performance (compared to visible and infrared wavelengths), as well as the passive ranging capability. Our setup using two antennas with a half-power beamwidth (HPBW) of 0.9$^circ$ and a stereoscopic baseline of 1.15 m allows ranging with an accuracy of$approxhbox10hbox%$ up to a distance of$approx$ 300 m. The range resolution improves with increasing stereoscopic baseline, lower radiometer noise, narrower antenna beams, and higher scene contrast. For scenes with sufficient contrast, the directional resolution is considerably better than the antenna HPBW. Thus, massive oversampling of the scene in the plane of the stereoscopic baseline is required. For our setup, an oversampling factor of 36 is optimal. Since additional ranging errors result from nonstationary scenes, fast scanning imagers should be applied. 相似文献