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激光雷达研制及其探测大气气溶胶的实验研究 总被引:7,自引:2,他引:5
作为一种激光探测大气气溶胶特征的新技术,采用分子滤波技术的高光变分辨率激光雷达在国际上得到了发展,给出了对这种YAG激光雷达系统的理论分析并建立了实验装置,其接收望远镜孔径为300mm,YAG激光脉冲能量为150mJ。通过数值模拟与初步测量估计了激光雷达性能,测量了大气回向散射信号,测量结果表明实结果与理论分析一致。 相似文献
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Using the US National Aeronautics and space Administration (NASA) Earth Observing-1 Mission (EO-1) hyperion hyperspectral remote sensing data, we study the shallow-water bathymetry inversion in Smith Island Bay. The fast line-of-sight atmospheric analysis of spectral hypercubes module is applied for atmospheric correction, and principal component analysis method combined with scatter diagram and maximum likelihood classification is used for seabed classification. The diffuse attenuation coefficient Kd is derived using quasi-analytical algorithm (QAA), which performs well in optically deep water. Kd obtained from QAA requires correction, particularly those derived in some coastal areas with optically shallow water and calculated by direct inversion based on radiative transfer theory to obtain the bathymetry. The direct inversion method derives the water depth quickly, and matches the results from optimized algorithm. 相似文献
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本文在海洋辐射传递研究中建立了变换辐射传递模型,引入了信息传输的概念、理论和研究方法,运用光学信息处理、线性系统理论,较简洁地解决了与水中图象传输密切相关的海水光学传递函数、与海洋激光雷达密切相关的水中窄光束传输、与海洋光学遥感密切相关的海洋辐射传递逆问题、海洋深层特征辐射场分布等海洋光学目前所关注的问题。同时,在海洋光学实验测量方面,引入了光学信息处理方法,简便地完成了传统海洋光学所难以测定的海水小角度(0.05°—1°)散射、长距离海水光学传递函数的测量。 相似文献
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Usually, lidar detection systems are optimized for the measurement of the low intensity signal using the photon counting technique, but this approach results in the nonlinear signal response for the higher intensity signal. The problem is successfully solved by the combination of analog-to-digital (AD) and photon- counting (PC) detection. The optimized processing procedure of the signal combination of AD and PC is described, and the corrected result is analyzed and compared with the results by the dealt-time correction method. In this way, the accuracy of wind and aerosol measurement in the nonlinear range is improved. In addition, the signal-to-noise ratios (SNRs) of the two detection methods of AD and PC are compared in the overall dynamic range of signal for the performance analysis. 相似文献
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Noise reduction in LOS wind velocity of Doppler lidar using discrete wavelet analysis 总被引:1,自引:0,他引:1
The line of sight (LOS) wind velocity can be determined from the incoherent Doppler lidar backscattering signals. Noise and interference in the measurement greatly degrade the inversion accuracy. In this paper, we apply the discrete wavelet denoising method by using biorthogonal wavelets and adopt a distance-dependent thresholds algorithm to improve the accuracy of wind velocity measurement by incoherent Doppler lidar. The noisy simulation data are processed and compared with the true LOS wind velocity. The results are compared by the evaluation of both the standard deviation and correlation coefficient. The results suggest that wavelet denoising with distance-dependent thresholds can considerably reduce the noise and interfering turbulence for wind lidar measurement. 相似文献
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为了扩展空间多普勒激光雷达地面散射信号的应用范围,采用多个机载多普勒激光雷达飞行实验数据,对地面散射信号的强度、海拔高度、速度等特征进行了数据分析,并利用地面散射信号与上层大气信号强度的比值,可以等效体现地面反射率特征,即地面散射信号解算的海拔高度与数字海拔高度模型数据相吻合,两者平均值偏差小于20 m,标准偏差小于100 m;使用地面散射信号实现飞机速度校正,与使用飞机平台数据解算的结果具有较好的一致性,采用直接探测手段时,标准偏差小于1.5 m/s,采用相干探测手段时,标准偏差小于0.5 m/s,验证了利用地面散射实现空间平台速度校正的可行性。另外,针对云散射信号的存在和影响,提出了一种利用海拔高度数据比对的方法,实现云散射和地面散射的识别。 相似文献