【作者】 何海舰；

【导师】 陈春；

【作者基本信息】 东北师范大学 ， 地图学与地理信息系统， 2006， 硕士

【摘要】 航空、航天遥感平台上的传感器接收到的地物信息,由于地球大气的存在而得到衰减,因此,遥感器接收到的地物信息不能真实地反映地表。同时由于大气的吸收、散射等作用使得遥感器接收到的电磁信息复杂,因而遥感图像的大气辐射校正变得复杂。随着定量遥感技术迅速发展,特别是利用多传感器、多时相遥感数据进行土地利用和土地覆盖变化监测、全球资源环境分析、气候变化监测等的需要,使得遥感图像大气校正方法的研究越来越受到重视。地表目标的二向性反射特征早已为人们所认识,但是只是到近十几年才在遥感界得到重视和应用,这一方面要归功于大量的二向性反射分布函数(Bi-direction ReflectanceDistribution Function,简称BRDF)正向模型的深入研究,另一方面时由于目前人们对遥感定量化应用的要求越来越高,即不但要提供全球地面覆盖和大气的信息,还要提供有关地面覆盖和大气的结构信息以及精确的半球反射率数据,而这些是传统的垂直观测遥感方法所无法提供的。已往的遥感影像的大气校正模型多是建立在地表的朗伯体的假设之上的,没有考虑地表的非朗伯体特性和双向反射分布函数,这样在很大程度上是影响气溶胶反演精度不高的一个主要因素。BRDF主要分两类,一类是物理模型,包括几何光学模型和辐射传输模型,另一类为统计模型。实验证明将BRDF模型引入遥感影像的大气校正中对于其校正精度的提高是行之有效的。本文在研究大气辐射传输理论的基础上,同时考虑地表的非朗伯体特性和地表的双向性反射,研究基于辐射传输的大气校正方法,其实质是指根据反演的和实际测量的大气状况对遥感图像测量值进行调整,以消除大气影响进行大气校正。利用基于复杂的辐射传输原理建立起来的大气校正模型校正方法是精度较高的一种方法,基本原理是利用电磁波在大气中的辐射传输原理建立起来的模型对遥感图像进行大气校正的方法。更多还原

【Abstract】 The remote sensing from satellite or airborne platform of land or sea surface in thevisible and near infrared is strongly affected by the presence of the atmosphere on theSun-target-Sensor path. Due to the distortions and noises caused by the presence of theatmosphere on the Sun-target-Sensor path, the space-based and airborne remote sensinginformation in the solar spectral range do not directly characterize the surface objects. Itbecomes serious impediments for the quantitative analysis and measurement of resources andenvironment.The bidirectional reflectance is the common phenomenon of the electromagnetic wavereflection in nature, it reveals that the reflection has directivity relying on the incidentdirection. The ability of reflecting and dispersing the electromagnetic wave of targets areclosely related to its surface structural characteristic and material composition, the surface ofvarious targets could radiate the incident electromagnetism wave in any directions and formdifferent fringing flux function of material spectrum characteristic.In this paper, a code enabling simulations of the above problem has been advanced andstudied. The code is the improved those codes that has been advance based on Collaboration.It enables to simulate plane observations, to account for elevated targets, to take into accountnon lambertian surface boundary conditions, the bidirectional reflectance, and new gases(CH4,N2O,CO) have been integrated in the computation of the gaseous transmission. Thecomputation accuracy regarding Rayleigh and aerosol scattering effects has been improved bythe use of state of the art approximation and use of the successive orders of scattering method.The step used for spectral integration has been improved to 2.5 nanometers. Finally, allcommunity approved results have been integrated in the code.Sensitivity analysis is conducted by comparisons of corrected and uncorrectedreflectance data including spectral brightness.The research shows that this atmosphericsimulation model reduces the uncertainties in the process of electromagnetic wavetransmission and eliminates effectively the perturbation from geometricand system correctedremote sensing imagery.更多还原