基于星地测量和辐射传输模式的特定地域大气中分辨力光谱辐射特征

Characteristics of atmospheric moderate resolution spectral radiation in representative regions based on satellite ground measurement and radiative transfer model

利用中分辨力成像光谱仪数据,采用星地测量并结合中分辨力辐射传输模式,以巢湖流域及周边为实验区,计算得到该地区夏季实际大气层结下沿观测路径整层大气透过率、大气辐射、大气热辐射和大气散射的太阳辐射在中分辨力光谱上的特征,以及整层大气廓线。研究结果表明:受能见度影响,实验区两地点水体像元处的整层大气透过率数值略高于植被像元处;两地卫星入瞳处的程辐射和卫星探测器探测到的程辐射谱分布相似;在可见至近红外波段,大气程辐射和散射的太阳辐射谱分布相似性较强,且随着波长增加而数值均逐渐减小,而大气热辐射数值很小;两个地点在短波范围内路径热辐射很低且接近,随着波长的增加,热辐射明显增强,波长越长,两地点热辐射差别越明显;当日天气晴好,气溶胶含量较低,而且两地距离很近,因此两地的大气廓线数据基本相似。

A quantity of atmospheric moderate resolution radiation results at Chaohu Lake basin（water site and vegetation site） in summer are obtained,including transmittance along observation path,atmospheric radiance,atmospheric profiles,etc.,using MODIS（moderate resolution imaging spectroradiometer） data and radiative transfer model MODTRAN（moderate resolution transmission）.The results show that,influenced by visibility,the transmittance at water site is slightly higher.Spectral distributions of path radiance at the entrance pupil of satellite at the two sites are similar.In visible and near infrared bands,the path radiation is very similar to the scattered solar radiation,and they both decrease gradually with the increase of wavelength;the atmospheric thermal radiance is very small.At the two sites,the path thermal radiance are very small and similar,and both increase obviously as the wavelength increases.Moreover,the atmospheric profiles of the two sites are similar because of fine weather,low aerosol content and small distance between the two sites.