论文标题
用自动编码器深入学习辐射性大气转移
Deep Learning of Radiative Atmospheric Transfer with an Autoencoder
论文作者
论文摘要
随着来自太阳的电流能通过大气传播,它受到辐射转移效应的影响,包括吸收,发射和散射。建模这些影响对于地球和大气的科学遥感测量至关重要。例如,高光谱图像是一种数字图像的一种形式,这些形式是在像素中的许多(通常数百个光)中收集的。在传感器处测得的光量是发射阳光,大气辐射转移的结果以及地面上的材料的反射率,所有这些材料的每个波长都因多种物理现象而变化。因此,地面光谱或大气成分的测量需要每个波长分开这些不同的贡献。在本文中,我们创建了一种类似于将大气的自动编码器视为“噪声”和地面反射率的自动编码器,每次频谱的真相。我们通过通过Modtran(http://modtran.spectral.com/modtran \ _home)从实验室测量中获取光谱的随机样本来生成数十万个训练样品,并通过不同的大气输入来增加大气影响。理想情况下,这一过程可以创建一个自动编码器,该自动编码器将在高光谱图像中分离大气效应和地面反射率,这是一个称为大气补偿的过程,这是困难且耗时的,需要启发式近似值,物理量的估计和物理建模。尽管我们方法的准确性不如该领域的其他方法那样好,但这是将深入学习物理原理的不断增长领域应用于高光谱图像和遥感中的大气补偿领域的重要第一步。
As electro-optical energy from the sun propagates through the atmosphere it is affected by radiative transfer effects including absorption, emission, and scattering. Modeling these affects is essential for scientific remote sensing measurements of the earth and atmosphere. For example, hyperspectral imagery is a form of digital imagery collected with many, often hundreds, of wavelengths of light in pixel. The amount of light measured at the sensor is the result of emitted sunlight, atmospheric radiative transfer, and the reflectance off the materials on the ground, all of which vary per wavelength resulting from multiple physical phenomena. Therefore measurements of the ground spectra or atmospheric constituents requires separating these different contributions per wavelength. In this paper, we create an autoencoder similar to denoising autoencoders treating the atmospheric affects as 'noise' and ground reflectance as truth per spectrum. We generate hundreds of thousands of training samples by taking random samples of spectra from laboratory measurements and adding atmospheric affects using physics-based modelling via MODTRAN (http://modtran.spectral.com/modtran\_home) by varying atmospheric inputs. This process ideally could create an autoencoder that would separate atmospheric effects and ground reflectance in hyperspectral imagery, a process called atmospheric compensation which is difficult and time-consuming requiring a combination of heuristic approximations, estimates of physical quantities, and physical modelling. While the accuracy of our method is not as good as other methods in the field, this an important first step in applying the growing field of deep learning of physical principles to atmospheric compensation in hyperspectral imagery and remote sensing.