An innovative complex lidar system deployed on an airborne rotorcraft platform for remote sensing of atmospheric pollution is proposed and demonstrated.The system incorporates integrated-path differential absorption l...An innovative complex lidar system deployed on an airborne rotorcraft platform for remote sensing of atmospheric pollution is proposed and demonstrated.The system incorporates integrated-path differential absorption lidar(DIAL) and coherent-doppler lidar(CDL) techniques using a dual tunable TEA CO_(2)laser in the 9—11 μm band and a 1.55 μm fiber laser.By combining the principles of differential absorption detection and pulsed coherent detection,the system enables agile and remote sensing of atmospheric pollution.Extensive static tests validate the system’s real-time detection capabilities,including the measurement of concentration-path-length product(CL),front distance,and path wind speed of air pollution plumes over long distances exceeding 4 km.Flight experiments is conducted with the helicopter.Scanning of the pollutant concentration and the wind field is carried out in an approximately 1 km slant range over scanning angle ranges from 45°to 65°,with a radial resolution of 30 m and10 s.The test results demonstrate the system’s ability to spatially map atmospheric pollution plumes and predict their motion and dispersion patterns,thereby ensuring the protection of public safety.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
As positioning sensors,edge computation power,and communication technologies continue to develop,a moving agent can now sense its surroundings and communicate with other agents.By receiving spatial information from bo...As positioning sensors,edge computation power,and communication technologies continue to develop,a moving agent can now sense its surroundings and communicate with other agents.By receiving spatial information from both its environment and other agents,an agent can use various methods and sensor types to localize itself.With its high flexibility and robustness,collaborative positioning has become a widely used method in both military and civilian applications.This paper introduces the basic fundamental concepts and applications of collaborative positioning,and reviews recent progress in the field based on camera,LiDAR(Light Detection and Ranging),wireless sensor,and their integration.The paper compares the current methods with respect to their sensor type,summarizes their main paradigms,and analyzes their evaluation experiments.Finally,the paper discusses the main challenges and open issues that require further research.展开更多
Pulse echo accumulation is commonly employed in coherent Doppler wind LiDAR(light detection and ranging)under the assumption of steady wind.Here,the measured spectral data are analyzed in the time dimension and freque...Pulse echo accumulation is commonly employed in coherent Doppler wind LiDAR(light detection and ranging)under the assumption of steady wind.Here,the measured spectral data are analyzed in the time dimension and frequency dimension to cope with the temporal wind shear and achieve the optimal accumulation time.A hardware-efficient algorithm combining the interpolation and cross-correlation is used to enhance the wind retrieval accuracy by reducing the frequency sampling interval and then reduce the spectral width calculation error.Moreover,the temporal broadening effect and spatial broadening effect are decoupled according to the strategy we developed.展开更多
For time-of-flight(TOF)light detection and ranging(LiDAR),a three-channel high-performance transimpedance amplifier(TIA)with high immunity to input load capacitance is presented.A regulated cascade(RGC)as the input st...For time-of-flight(TOF)light detection and ranging(LiDAR),a three-channel high-performance transimpedance amplifier(TIA)with high immunity to input load capacitance is presented.A regulated cascade(RGC)as the input stage is at the core of the complementary metal oxide semiconductor(CMOS)circuit chip,giving it more immunity to input photodiode detectors.A simple smart output interface acting as a feedback structure,which is rarely found in other designs,reduces the chip size and power consumption simultaneously.The circuit is designed using a 0.5μm CMOS process technology to achieve low cost.The device delivers a 33.87 dB?transimpedance gain at 350 MHz.With a higher input load capacitance,it shows a-3 dB bandwidth of 461 MHz,indicating a better detector tolerance at the front end of the system.Under a 3.3 V supply voltage,the device consumes 5.2 mW,and the total chip area with three channels is 402.8×597.0μm2(including the test pads).展开更多
为了提高基于车载LiDAR点云数据的地面点提取精度,最大限度发挥车载LiDAR点云数据的利用效率。本文提出了一种基于Otsu算法与最远点采样(Farthest Point Sampling,FPS)算法的地面点提取方法。首先,根据Otsu算法自适应计算高程分割阈值,...为了提高基于车载LiDAR点云数据的地面点提取精度,最大限度发挥车载LiDAR点云数据的利用效率。本文提出了一种基于Otsu算法与最远点采样(Farthest Point Sampling,FPS)算法的地面点提取方法。首先,根据Otsu算法自适应计算高程分割阈值,滤除大部分地面点,实现地面点的粗提取;其次从地面点粗提取结果中随机选取一个种子点,并使用FPS算法选取剩余种子点进行最优平面模型拟合提取精确地面点。通过两组实验数据进行地面点提取实验,结果表明,两组实验数据地面点提取结果误差均在8%以内,验证了本文方法的有效性与适用性。展开更多
文摘An innovative complex lidar system deployed on an airborne rotorcraft platform for remote sensing of atmospheric pollution is proposed and demonstrated.The system incorporates integrated-path differential absorption lidar(DIAL) and coherent-doppler lidar(CDL) techniques using a dual tunable TEA CO_(2)laser in the 9—11 μm band and a 1.55 μm fiber laser.By combining the principles of differential absorption detection and pulsed coherent detection,the system enables agile and remote sensing of atmospheric pollution.Extensive static tests validate the system’s real-time detection capabilities,including the measurement of concentration-path-length product(CL),front distance,and path wind speed of air pollution plumes over long distances exceeding 4 km.Flight experiments is conducted with the helicopter.Scanning of the pollutant concentration and the wind field is carried out in an approximately 1 km slant range over scanning angle ranges from 45°to 65°,with a radial resolution of 30 m and10 s.The test results demonstrate the system’s ability to spatially map atmospheric pollution plumes and predict their motion and dispersion patterns,thereby ensuring the protection of public safety.
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。
基金National Natural Science Foundation of China(Grant No.62101138)Shandong Natural Science Foundation(Grant No.ZR2021QD148)+1 种基金Guangdong Natural Science Foundation(Grant No.2022A1515012573)Guangzhou Basic and Applied Basic Research Project(Grant No.202102020701)for providing funds for publishing this paper。
文摘As positioning sensors,edge computation power,and communication technologies continue to develop,a moving agent can now sense its surroundings and communicate with other agents.By receiving spatial information from both its environment and other agents,an agent can use various methods and sensor types to localize itself.With its high flexibility and robustness,collaborative positioning has become a widely used method in both military and civilian applications.This paper introduces the basic fundamental concepts and applications of collaborative positioning,and reviews recent progress in the field based on camera,LiDAR(Light Detection and Ranging),wireless sensor,and their integration.The paper compares the current methods with respect to their sensor type,summarizes their main paradigms,and analyzes their evaluation experiments.Finally,the paper discusses the main challenges and open issues that require further research.
基金Project supported by the Shanghai Science and Technology Innovation Action(Grant No.22dz1208700).
文摘Pulse echo accumulation is commonly employed in coherent Doppler wind LiDAR(light detection and ranging)under the assumption of steady wind.Here,the measured spectral data are analyzed in the time dimension and frequency dimension to cope with the temporal wind shear and achieve the optimal accumulation time.A hardware-efficient algorithm combining the interpolation and cross-correlation is used to enhance the wind retrieval accuracy by reducing the frequency sampling interval and then reduce the spectral width calculation error.Moreover,the temporal broadening effect and spatial broadening effect are decoupled according to the strategy we developed.
文摘For time-of-flight(TOF)light detection and ranging(LiDAR),a three-channel high-performance transimpedance amplifier(TIA)with high immunity to input load capacitance is presented.A regulated cascade(RGC)as the input stage is at the core of the complementary metal oxide semiconductor(CMOS)circuit chip,giving it more immunity to input photodiode detectors.A simple smart output interface acting as a feedback structure,which is rarely found in other designs,reduces the chip size and power consumption simultaneously.The circuit is designed using a 0.5μm CMOS process technology to achieve low cost.The device delivers a 33.87 dB?transimpedance gain at 350 MHz.With a higher input load capacitance,it shows a-3 dB bandwidth of 461 MHz,indicating a better detector tolerance at the front end of the system.Under a 3.3 V supply voltage,the device consumes 5.2 mW,and the total chip area with three channels is 402.8×597.0μm2(including the test pads).
文摘为了提高基于车载LiDAR点云数据的地面点提取精度,最大限度发挥车载LiDAR点云数据的利用效率。本文提出了一种基于Otsu算法与最远点采样(Farthest Point Sampling,FPS)算法的地面点提取方法。首先,根据Otsu算法自适应计算高程分割阈值,滤除大部分地面点,实现地面点的粗提取;其次从地面点粗提取结果中随机选取一个种子点,并使用FPS算法选取剩余种子点进行最优平面模型拟合提取精确地面点。通过两组实验数据进行地面点提取实验,结果表明,两组实验数据地面点提取结果误差均在8%以内,验证了本文方法的有效性与适用性。