A Synergic Application of TERRA and AQUA on Retrieving Aerosol Optical Depth over Land
利用TERRA和AQUA共同反演陆地上空的气溶胶光学厚度

MODIS instruments aboard on Terra and Aqua are used to synchronously retrieve aerosol optical depth(AOD) and surface reflectance properties, and themain principles andmethods to derive aerosolproducts from satellites are discussed in detai.l The aerosol optical depth and surface reflectance over Beijing are obtained by applying themulti-channelmeasurements from Terra andAqua in theirdifferentobserving angles to the same surface site. The satellite retrieval results are well consistent with surface sun-photometer observations. The retrieved results of surface reflectance and aerosol ngstr m exponent are discussed by comparing them with surfacemeasurements and literature results. Our results show that in Beijing region the reflectance radio is about0. 66 ofMODIS channel 1 over channel 7 and about 0. 28 ofMODIS channel 3 to channel1. Comparedwith the data used by dark dense vegetation background algorithm proposed byNASA for global retrieva,l .i e. 0. 50 and 0. 25 on the two channels, the finalAOD results from ourmethod are more consistentwith the surface sun-photometer observations.