闪电的光辐射能分布特征   总被引：2，自引：1，他引：1  

郄秀书  谢屹然  Ralf Toumi 《高原气象》2004,23(4):476-480

对TRMM卫星上装载的闪电成像仪(LIS)所获取的闪电光辐射能进行了分析,发现在不同地区和不同的空间、时间尺度上闪电光辐射能都很好地遵循对数正态分布。文中利用了一个国际上公认的一维雷暴云起电和放电模式,对闪电放电中和的电荷量进行了数值模拟。蒙特卡罗算法表明,闪电放电所中和的电荷量也遵循对数正态分布,云中的软雹浓度、破碎系数、温度递减率、放电的电场阈值等参量的综合作用可以对其进行较好的解释,而其中任意一种参量的单独作用则不然。  相似文献   

On the separate retrieval of soil and vegetation temperatures from ATSR data     

Li Zhaoliang  ZHANG Renhua  JIA Li  SU Zhongbo 《中国科学D辑(英文版)》2001,44(2):97-111

  相似文献   

A new model on bidirectional reflectance surface-atmospheric coupled radiation     

邱金桓 《中国科学D辑(英文版)》2001,44(4):298-306

An exact and available model on bidirectional reflectance surface-atmospheric coupled radiation is of great significance for spaceborne remote sensing application. Based on the physical process of interaction of solar radiation with the surface and the atmosphere, a new model on bidirectional reflectance surface-atmospheric coupled radiation is developed in this paper. As shown in numerical simulation, this model is evidently better than the 6S model. The standard error among 110112 sets of upward radiance data calculated by this new model is only 0.49%, which is about one fourth of the one by 6S. In the condition of the solar zenith angle θ_s⩽75° and the viewing angle θ _v⩽ 60°, the error by the new model is usually smaller than 2.5%.  相似文献   

卫星遥感大气订正的参数化模式及其模拟应用   总被引：2，自引：0，他引：2  

邱金恒 《遥感学报》2001,5(6):401-406

发展了一个用于卫星大气订正的参数化模式,包括一个新的程辐射亮度模式和一个参数化的朗伯地表一大气辐射耦合引起的亮度增量模式.应用最小二乘法,程辐射亮度被参数化为大气总光学厚度、一次散射反照率、太阳天顶角、视天顶角、方位角、大气不对称因子的函数.应用这一参数化的亮度模式进行大气订正应用的数值模拟,即进行卫星遥感地表光谱反照率的模拟试验.数值检验结果表明对于865 nm,670nm,550nm和412nm 4个MODIS通道,在0°-70°的太阳天顶角、0°-60°视观测角以及0.05-0.8的地表反照率条件下,参数化的向上辐射亮度的标准差小于4%,由该参数化亮度模式引起的地表反照率解的标准差小于0.03.  相似文献   

STUDYING THE SKY RADIANCE AND DEGREE OF POLARIZATION AND SOUNDING THE OPTICAL CHARACTERISTICS OF ATMOSPHERIC AEROSOL          下载免费PDF全文

Zhao Xuepeng  Zhou Xiuji  Xue Qingyu  Guo Song 《Acta Meteorologica Sinica》1991,5(3):360-369

The sky radiance and degree of polarization with multiple scattering process considered were calculated inthis paper by solving vector form radiative transfer equation iteratively. Numerical experiment for simultaneouslyretriving the size distribution (SD) and the complex refractive index (CRI) of aerosol particle was conductedwith the degree of polarization of skylight (DPS) and the library method used. It is shown from the resultsthat the real part of CRI is always sensitive to DPS. But situation is somewhat complicated for the imaginarypart of CRI. Therefore, it is expected that the real part of CRI can be retrieved from DPS and its imaginarypart should be retrieved as the particle is large in size. In this paper, seven sets of DPS measurements on 6 January,1990 in Beijing were given and the optical characteristics of aerosol were retrieved.  相似文献   

机载成像光谱仪图像大气程辐射影响归一化及其简化校正   总被引：1，自引：0，他引：1  

杨超武  田庆久  张满郎 《测绘学报》1997,(4)

航空成像光谱仪得到的图像，其临边的辐射值与飞机正下方（天底点）的辐射值差别较大，此种现像称之为扫描图像的临边效应，它严重影响图像的质量，使图像的有效使用面积大为减少，还可能引起错误的判读，为了消除这种影响。本文提出一种物理意义明确，在实施过程中简单易行，而有效的方法，文中将详述航空飞行方式、数据及图像处理方法，而不涉及星载扫描图像的处理问题。  相似文献   

The Impact of Satellite Radiance Data Assimilation within a Frequently Updated Regional Forecast System Using a GSI-based Ensemble Kalman Filter     

Kefeng ZHU  Ming XUE  Yujie PAN  Ming HU  Stanley G. BENJAMIN  Stephen S. WEYGANDT  Haidao LIN 《大气科学进展》2019,36(12):1308-1326

A regional ensemble Kalman filter (EnKF) data assimilation (DA) and forecast system was recently established based on the Gridpoint Statistical Interpolation (GSI) analysis system. The EnKF DA system was tested with continuous threehourly updated cycles followed by 18-h deterministic forecasts from every three-hourly ensemble mean analysis. Initial tests showed negative to neutral impacts of assimilating satellite radiance data due to the improper bias correction procedure. In this study, two bias correction schemes within the established EnKF DA system are investigated and the impact of assimilating additional polar-orbiting satellite radiance is also investigated. Two group experiments are conducted. The purpose of the first group is to evaluate the bias correction procedure. Two online bias correction methods based on GSI 3DVar and EnKF algorithms are used to assimilate AMSU-A radiance data. Results show that both variational and EnKF-based bias correction procedures effectively reduce the observation and background radiance differences, achieving positive impacts on forecasts. With proper bias correction, we assimilate full radiance observations including AMSU-A, AMSU-B, AIRS, HIRS3/4, and MHS in the second group. The relative percentage improvements(RPIs) for all forecast variables compared to those without radiance data assimilation are mostly positive, with the RPI of upper-air relative humidity being the largest. Additionally, precipitation forecasts on a downscaled 13-km grid from 40-km EnKF analyses are also improved by radiance assimilation for almost all forecast hours.  相似文献   

海水层辐射校准技术研究     

陈清莲  唐军武  王项南  冯林新  任洪启 《海洋技术学报》2001,20(1):161-164

为提高光学资料的利用率，确保光学遥感信息的精确度，必须对卫星获得的资料进行辐射校准，本文着重阐述我们通过在我国典型海区实测获取与卫星同步的海面归一化离水辐射率，对实用的大气模型进行选择及参数修正的研究，对卫星遥感资料获得的海面离水辐射率进行校准，论文给出了研究的一些主要结果。  相似文献   

光谱仪测量离水辐射亮度的方法   总被引：7，自引：0，他引：7  

李铜基  唐军武  陈清莲  任洪 《热带海洋学报》2001,20(4):56-60

概述了利用光谱仪在水面上方进行水表光学特性测量和基本原理与测量方法，以及处理和计算离水辐射亮度、归一化离水辐射亮度及遥感反射比等水表光学特性参数的主要方法。对1998年东海3个站点的测量数据进行了处理和分析，并与剖面法计算结果进行了比较。  相似文献   

Atmospheric correction for China''s coastal water color remote sensing   总被引：14，自引：0，他引：14  

Pan Delu  Mao Zhihua 《海洋学报(英文版)》2001,20(3):343-354

INTRODUcrIONMeasurements from satellite have demonstrated that space sensor can be applied to measurethe sPectra of water-leaving radiance and proven that ocean color remote sensing is a powerfultcol for understanding oceanic, biological and physical processes. One sPecial ocean color satel-lite heaStar was successfully launched in August l997. It has brought to oceanOgraphers a wel-comed and improvd renewal of the ocean color of CZCS, VHRSR and arS. ffeaWiFS con-tributes much bette…  相似文献