利用TERRA和AQUA共同反演气溶胶光学厚度和地表反射率特征，对其原理及方法进行了详细的讨论。通过Terra和Aqua两颗卫星对同一地点的不同角度的观测，结合多个光学通道的信息，反演了北京地区光学厚度及地表反射率信息。反演的气溶胶光学厚度同地面观测的结果相比具有很好的一致性。同时，对地表反射率及气溶胶波长指数等也进行了讨论和对比，结果显示，对北京地区，MODIS1通道地表反射率和7通道地表反射率的比在0．66左右，3通道和7通道的比在0．28左右。相比于NASA暗背景全球反演算法中1、3通道和7通道的比为0．50和0．25的处理方法，反演得到的气溶胶光学厚度结果也较好。

MODIS instruments aboard on Terra and Aqua are used to synchronously retrieve aerosol optical\ndepth(AOD) and surface reflectance properties, and themain principles andmethods to derive aerosolproducts\nfrom satellites are discussed in detai.l The aerosol optical depth and surface reflectance over Beijing are\nobtained by applying themulti-channelmeasurements from Terra andAqua in theirdifferentobserving angles to\nthe same surface site. The satellite retrieval results are well consistent with surface sun-photometer\nobservations. The retrieved results of surface reflectance and aerosol ngstr m exponent are discussed by\ncomparing them with surfacemeasurements and literature results. Our results show that in Beijing region the\nreflectance radio is about0. 66 ofMODIS channel 1 over channel 7 and about 0. 28 ofMODIS channel 3 to\nchannel1. Comparedwith the data used by dark dense vegetation background algorithm proposed byNASA for\nglobal retrieva,l .i e. 0. 50 and 0. 25 on the two channels, the finalAOD results from ourmethod are more\nconsistentwith the surface sun-photometer observations.