Feasibility study on 1.6 μm continuous-wave modulation laser absorption spectrometer system for measurement of global CO2 concentration from a satellite.
Feasibility study on 1.6 μm continuous-wave modulation laser absorption spectrometer system for measurement of global CO2 concentration from a satellite.
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DOI：
10.1364/ao.50.002055
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发表时间：
2011-05
期刊：
影响因子：
1.9
通讯作者：
S. Kameyama;M. Imaki;Y. Hirano;S. Ueno;S. Kawakami;D. Sakaizawa;T. Kimura;M. Nakajima
中科院分区：
文献类型：
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作者：
S. Kameyama;M. Imaki;Y. Hirano;S. Ueno;S. Kawakami;D. Sakaizawa;T. Kimura;M. Nakajima
研究了利用1.6 μm连续波调制激光吸收光谱仪测量全球CO2浓度的可行性。进行了波长选择和系统和随机误差分析的研究。差分吸收光学深度（DAOD）中的系统误差主要由温度估计误差、表面压力估计误差、高度估计误差和ON波长不稳定性引起。当背景气溶胶和尘埃气溶胶的后向散射系数在高度上具有简单的分布时，通过使用200 kHz左右的调制频率，可以将由背景气溶胶和尘埃气溶胶的不需要的后向散射引起的系统误差减小到小于0.26%。卷云后向散射的影响远大于沙尘气溶胶。将DAOD中的随机误差减小到0.26%所需的传输功率由信噪比和载噪比计算确定。对于400 km的卫星高度和1 m的接收孔径直径，当λ/d 0为0.31和0.08时，所需的发射功率分别约为18 W和70 W;在这种情况下，总测量时间为4 s，这对应于28 km的水平分辨率。
A feasibility study is carried out on a 1.6 μm continuous-wave modulation laser absorption spectrometer system for measurement of global CO(2)concentration from a satellite. The studies are performed for wavelength selection and both systematic and random error analyses. The systematic error in the differential absorption optical depth (DAOD) is mainly caused by the temperature estimation error, surface pressure estimation error, altitude estimation error, and ON wavelength instability. The systematic errors caused by unwanted backscattering from background aerosols and dust aerosols can be reduced to less than 0.26% by using a modulation frequency of around 200 kHz, when backscatter coefficients of these unwanted backscattering have a simple profile on altitude. The influence of backscattering from cirrus clouds is much larger than that of dust aerosols. The transmission power required to reduce the random error in the DAOD to 0.26% is determined by the signal-to-noise ratio and the carrier-to-noise ratio calculations. For a satellite altitude of 400 km and receiving aperture diameter of 1 m, the required transmission power is approximately 18 W and 70 W when albedo is 0.31 and 0.08, respectively; the total measurement time in this case is 4 s, which corresponds to a horizontal resolution of 28 km.