中波红外火情遥感的大气辐射传输特性

Atmospheric radiation transmission character for fire detection in medium infrared spectrum

分析2005年在广西武鸣机场进行的人工火情测量试验中获得的由BOMEM MR-154FT高光谱仪测定的火情光谱特征发现:在中波4.34～4.76μm光谱段的辐亮度比火情遥感监测常用通道3.5～4.0μm有更强的响应关系。用模拟计算方法进一步分析了中波红外光谱的大气辐射特性。分别对中波波段主要的吸收气体(水汽、水汽连续、二氧化碳混合、二氧化碳、一氧化二氮、臭氧和气溶胶)影响辐射传输的情况进行模拟计算;选择中国内陆地区18种大气廓线样本和4种大气模型,分别进行辐射传输计算,获得了3～5μm谱段分谱大气透过率和大气程辐射等,并比较了新选择通道(4.42～4.78μm)与传统通道(3.55～3.95μm)在地面和传输到大气层顶后辐亮度的变化情况,为今后应用新探测通道奠定了基础。

Analyzing the fire spectrum measured by the BOMEM MR-154 FT spectrometer during the manual fire experiment in 2005, Guangxi province, it was discovered that radiance in 4.34-4.76 μm waveband had a stronger response relationship than that in the 3.5-4.0 μm waveband commonly used to detect the fire. The character of atmospheric radiation transmission in medium wave infrared detective waveband was analyzed again by the simulative calculation method. The influences of main absorption gas （water vapor, continuous water vapor, mixed CO2, CO2, N2O, O3, aerosol） on radiation transmission in medium wave infrared channel were simulatively calculated. The radiaton transmission was calculated separately by selecting 18 atmosphere profiles samples of China's Mainland and 4 standard atmospheric models. The atmosphere spectral transmittance and atmospheric path radiance of 3-5 μm medium wave infrared waveband were calculated. The difference of radiance varieties during the transmission from ground to the top of the atmosphere were compared between the new selected 4.42-4.78 μm waveband and traditional 3.55-3.95 μm waveband. The study will lay the foundation for using the new selected channel in the future.