介绍一种利用水声信道的统计不变特征(波导不变量)实现被动测距的方法。对接收LOFAR(Low FrequencyAnalysis Record)图使用HOUGH变换等边缘提取技术提取条纹,得到波导不变量以及抛物线参数的估计值,进而得到目标的CPA(Closest Point of ...介绍一种利用水声信道的统计不变特征(波导不变量)实现被动测距的方法。对接收LOFAR(Low FrequencyAnalysis Record)图使用HOUGH变换等边缘提取技术提取条纹,得到波导不变量以及抛物线参数的估计值,进而得到目标的CPA(Closest Point of Approach)点距离。矢量水听器的振速通道数据所得LOFAR图信噪比明显高于声压LOFAR图,可以提高测距精度。仿真和试验数据结果显示本方法能以较高的精度提取CPA点距离。对比波导不变量经验值和在线估计值所得最近点距离结果,发现使用具有一定精度的在线估计波导不变量值可以显著提高测距精度。展开更多
对机场场面航空器滑行冲突检测进行了研究,分析了基于多摄像机的航空器滑行冲突检测流程,基于图像识别和目标跟踪技术,提取航空器的滑行轨迹,提出了基于DCPA(distance of closest point of approach)和TCPA(time of closet point of app...对机场场面航空器滑行冲突检测进行了研究,分析了基于多摄像机的航空器滑行冲突检测流程,基于图像识别和目标跟踪技术,提取航空器的滑行轨迹,提出了基于DCPA(distance of closest point of approach)和TCPA(time of closet point of approach)的滑行冲突检测模型,开发了基于多摄像机的航空器滑行冲突检测原型系统并应用于西南某通航机场;实验结果表明,基于多摄像机视频目标跟踪和冲突检测模型可有效地检测机场场面航空器的滑行冲突,可作为中小机场主要监视手段以及大型机场场监雷达系统的辅助,防止航空器机场滑行冲突,提高机场场面运行安全和效率。展开更多
Volume parameter is the basic content of a spatial body object morphology analysis.However,the challenge lies in the volume calculation of irregular objects.The point cloud slicing method proposed in this study effect...Volume parameter is the basic content of a spatial body object morphology analysis.However,the challenge lies in the volume calculation of irregular objects.The point cloud slicing method proposed in this study effectively works in calculating the volume of the point cloud of the spatial object obtained through three-dimensional laser scanning(3DLS).In this method,a uniformly spaced sequent slicing process is first conducted in a specific direction on the point cloud of the spatial object obtained through 3DLS.A series of discrete point cloud slices corresponding to the point cloud bodies are then obtained.Subsequently,the outline boundary polygon of the point cloud slicing is searched one by one in accordance with the slicing sequence and areas of the polygon.The point cloud slice is also calculated.Finally,the individual point cloud section volume is calculated through the slicing areas and the adjacent slicing gap.Thus,the total volume of the scanned spatial object can be calculated by summing up the individual volumes.According to the results and analysis of the calculated examples,the slice-based volume-calculating method for the point cloud of irregular objects obtained through 3DLS is correct,concise in process,reliable in results,efficient in calculation methods,and controllable on accuracy.This method comes as a good solution to the volume calculation of irregular objects.展开更多
文摘介绍一种利用水声信道的统计不变特征(波导不变量)实现被动测距的方法。对接收LOFAR(Low FrequencyAnalysis Record)图使用HOUGH变换等边缘提取技术提取条纹,得到波导不变量以及抛物线参数的估计值,进而得到目标的CPA(Closest Point of Approach)点距离。矢量水听器的振速通道数据所得LOFAR图信噪比明显高于声压LOFAR图,可以提高测距精度。仿真和试验数据结果显示本方法能以较高的精度提取CPA点距离。对比波导不变量经验值和在线估计值所得最近点距离结果,发现使用具有一定精度的在线估计波导不变量值可以显著提高测距精度。
文摘对机场场面航空器滑行冲突检测进行了研究,分析了基于多摄像机的航空器滑行冲突检测流程,基于图像识别和目标跟踪技术,提取航空器的滑行轨迹,提出了基于DCPA(distance of closest point of approach)和TCPA(time of closet point of approach)的滑行冲突检测模型,开发了基于多摄像机的航空器滑行冲突检测原型系统并应用于西南某通航机场;实验结果表明,基于多摄像机视频目标跟踪和冲突检测模型可有效地检测机场场面航空器的滑行冲突,可作为中小机场主要监视手段以及大型机场场监雷达系统的辅助,防止航空器机场滑行冲突,提高机场场面运行安全和效率。
文摘Volume parameter is the basic content of a spatial body object morphology analysis.However,the challenge lies in the volume calculation of irregular objects.The point cloud slicing method proposed in this study effectively works in calculating the volume of the point cloud of the spatial object obtained through three-dimensional laser scanning(3DLS).In this method,a uniformly spaced sequent slicing process is first conducted in a specific direction on the point cloud of the spatial object obtained through 3DLS.A series of discrete point cloud slices corresponding to the point cloud bodies are then obtained.Subsequently,the outline boundary polygon of the point cloud slicing is searched one by one in accordance with the slicing sequence and areas of the polygon.The point cloud slice is also calculated.Finally,the individual point cloud section volume is calculated through the slicing areas and the adjacent slicing gap.Thus,the total volume of the scanned spatial object can be calculated by summing up the individual volumes.According to the results and analysis of the calculated examples,the slice-based volume-calculating method for the point cloud of irregular objects obtained through 3DLS is correct,concise in process,reliable in results,efficient in calculation methods,and controllable on accuracy.This method comes as a good solution to the volume calculation of irregular objects.
