The multilongitudinal mode[MLM]high-spectral-resolution lidar[HSRL]based on the Mach±Zehnder interferometer[MZI]is constructed in Xi’an for accurate measurements of aerosol optical properties.The critical requir...The multilongitudinal mode[MLM]high-spectral-resolution lidar[HSRL]based on the Mach±Zehnder interferometer[MZI]is constructed in Xi’an for accurate measurements of aerosol optical properties.The critical requirement of the optimal match between the free spectral range of MZI and the longitudinal mode interval of the MLM laser is influenced by the laboratory temperature,pressure,and vibration.To realize the optimal separation of aerosol Mie scattering signals and molecular Rayleigh scattering signals excited by the MLM laser,a self-tuning technique to dynamically adjust the optical path difference[OPD]of the MZI is proposed,which utilizes the maximum ratio between the received power of the Mie channel and Rayleigh channel as the criterion of the OPD displacement.The preliminary experiments show the feasibility of the MLM-HSRL with self-tuning MZI and the stable performance in the separation of aerosol Mie scattering signals and molecular Rayleigh scattering signals.展开更多
针对现有机载LiDAR(light detection and ranging)点云滤波方法在地形起伏剧烈的林区适用性不足的问题,提出一种多分辨率层次布料模拟滤波方法。首先,通过多尺度形态学开运算选择大量种子地面点;然后,基于种子地面点,使用布料模拟法由...针对现有机载LiDAR(light detection and ranging)点云滤波方法在地形起伏剧烈的林区适用性不足的问题,提出一种多分辨率层次布料模拟滤波方法。首先,通过多尺度形态学开运算选择大量种子地面点;然后,基于种子地面点,使用布料模拟法由低至高逐层构建参考地形,以快速获取高分辨率参考地形;最后,基于点至参考地形的高差区分地面点和非地面点。利用国际摄影测量和遥感学会提供的数据集和参考方法,评估该方法性能。利用在中国、美国多个代表性林区的点云数据,评估该方法的可推广性。结果表明,该方法的Kappa系数和运行时间是83.72%和34.11 s,精度和效率较经典布料模拟滤波方法提高10.49%和52.17%。相比8种参考方法,该方法能够获得更高精度,并且具有稳定的可推广性。展开更多
机载激光雷达(LiDAR,light detection and ranging)数据能有效去除植被,获取真实的地表形态,从而为植被覆盖区的地质灾害风险评价提供新的方法和手段。汕尾火山嶂山体陡峻、植被茂密,是滑坡、崩塌和泥石流的易发地,本文首先采用高分辨率...机载激光雷达(LiDAR,light detection and ranging)数据能有效去除植被,获取真实的地表形态,从而为植被覆盖区的地质灾害风险评价提供新的方法和手段。汕尾火山嶂山体陡峻、植被茂密,是滑坡、崩塌和泥石流的易发地,本文首先采用高分辨率LiDAR数据生成高精度DEM数据以及坡度、坡向、曲率、起伏度、粗糙度和山体阴影等地形因子,综合高分一号遥感影像进行滑坡/崩塌解译共获得滑坡/崩塌44处;然后基于变维分形模型确定各解译因子对滑坡/崩塌形成的权重后计算获得每个解译滑坡/崩塌的确认概率,剔除概率较低的滑坡/崩塌3处;最后根据沟谷特征将火山嶂划分为6个子区,基于各个子区的地形特征、滑坡/崩塌密度和体量以及人类活动分布进行地质灾害风险评价。结果表明基于LiDAR数据生成的高精度地形因子可以有效地去除植被影响,是植被覆盖区地质灾害解译的有效手段。展开更多
基金supported by the National Natural Science Foundation of China(Nos.42175149 and 41775035)the China-CEEC Joint Higher Education Project(No.202017)the Natural Science Foundation of Shaanxi Province,China(No.2020JM-445)。
文摘The multilongitudinal mode[MLM]high-spectral-resolution lidar[HSRL]based on the Mach±Zehnder interferometer[MZI]is constructed in Xi’an for accurate measurements of aerosol optical properties.The critical requirement of the optimal match between the free spectral range of MZI and the longitudinal mode interval of the MLM laser is influenced by the laboratory temperature,pressure,and vibration.To realize the optimal separation of aerosol Mie scattering signals and molecular Rayleigh scattering signals excited by the MLM laser,a self-tuning technique to dynamically adjust the optical path difference[OPD]of the MZI is proposed,which utilizes the maximum ratio between the received power of the Mie channel and Rayleigh channel as the criterion of the OPD displacement.The preliminary experiments show the feasibility of the MLM-HSRL with self-tuning MZI and the stable performance in the separation of aerosol Mie scattering signals and molecular Rayleigh scattering signals.
文摘针对现有机载LiDAR(light detection and ranging)点云滤波方法在地形起伏剧烈的林区适用性不足的问题,提出一种多分辨率层次布料模拟滤波方法。首先,通过多尺度形态学开运算选择大量种子地面点;然后,基于种子地面点,使用布料模拟法由低至高逐层构建参考地形,以快速获取高分辨率参考地形;最后,基于点至参考地形的高差区分地面点和非地面点。利用国际摄影测量和遥感学会提供的数据集和参考方法,评估该方法性能。利用在中国、美国多个代表性林区的点云数据,评估该方法的可推广性。结果表明,该方法的Kappa系数和运行时间是83.72%和34.11 s,精度和效率较经典布料模拟滤波方法提高10.49%和52.17%。相比8种参考方法,该方法能够获得更高精度,并且具有稳定的可推广性。
文摘机载激光雷达(LiDAR,light detection and ranging)数据能有效去除植被,获取真实的地表形态,从而为植被覆盖区的地质灾害风险评价提供新的方法和手段。汕尾火山嶂山体陡峻、植被茂密,是滑坡、崩塌和泥石流的易发地,本文首先采用高分辨率LiDAR数据生成高精度DEM数据以及坡度、坡向、曲率、起伏度、粗糙度和山体阴影等地形因子,综合高分一号遥感影像进行滑坡/崩塌解译共获得滑坡/崩塌44处;然后基于变维分形模型确定各解译因子对滑坡/崩塌形成的权重后计算获得每个解译滑坡/崩塌的确认概率,剔除概率较低的滑坡/崩塌3处;最后根据沟谷特征将火山嶂划分为6个子区,基于各个子区的地形特征、滑坡/崩塌密度和体量以及人类活动分布进行地质灾害风险评价。结果表明基于LiDAR数据生成的高精度地形因子可以有效地去除植被影响,是植被覆盖区地质灾害解译的有效手段。