CAJ | 학술논문

卫星短波红外 CO2遥感获得大气低层 CO2浓度信息，已成为目前国际热点研究领域。结合气候变化及碳源、汇观测需求，利用高精度大气辐射传输模式研究了高光谱分辨率、高精度 CO2探测目标的可实现性。针对高光谱CO2探测器光栅分光、阵列探测器特点，分析了光谱分辨率、光谱采样率等关键技术指标对 CO2探测的可能影响；基于辐射敏感度因子分析了不同探测精度要求下的信噪比需求。结果表明：高光谱 CO2探测器首先应具有足够高的光谱分辨率，以便从太阳反射连续谱段中分辨出 CO2吸收线；为保证 CO2光谱的准确性，光谱仪所用探测器面元应该保证光谱采样率大于2；尽管探测边界层内 CO2浓度1％变化所要求的信噪比难以达到，但探测整层大气CO2浓度1％的变化所需要的信噪比是可以实现的。
위성단파홍외 CO2요감획득대기저층 CO2농도신식，이성위목전국제열점연구영역。결합기후변화급탄원、회관측수구，이용고정도대기복사전수모식연구료고광보분변솔、고정도 CO2탐측목표적가실현성。침대고광보CO2탐측기광책분광、진렬탐측기특점，분석료광보분변솔、광보채양솔등관건기술지표대 CO2탐측적가능영향；기우복사민감도인자분석료불동탐측정도요구하적신조비수구。결과표명：고광보 CO2탐측기수선응구유족구고적광보분변솔，이편종태양반사련속보단중분변출 CO2흡수선；위보증 CO2광보적준학성，광보의소용탐측기면원응해보증광보채양솔대우2；진관탐측변계층내 CO2농도1％변화소요구적신조비난이체도，단탐측정층대기CO2농도1％적변화소수요적신조비시가이실현적。
With the stable increase of carbon dioxide (CO2 )concentrations,space based measurement of CO2 concentration in lower atmosphere by reflected sunlight in near infrared band has become a hot research topic.Recently,instruments sensitive to total CO2 column data in near-surface have become available through the SCIAMACHY instrument on ENVISAT and TANSO-FTS on GOSAT.The developing hyper spectral CO2 detector in China carried by TANSAT is going to be launched in 2015.Hyper spectral CO2 detector is designed to provide global measurements of CO2 in lower troposphere,employing high resolu-tion spectra of reflected sunlight taken simultaneously in near-infrared CO2 (1.61 μm and 2.06 μm)and O2 (0.76 μm)bands. <br> Associated with climate change and observation requirements of carbon sources and sinks,the feasibil-ity of making CO2 column concentration measurements with high-resolution and high-precision is studied by high resolution atmosphere radiation transfer model.In consideration of the application requirements, effects of key specifications of the hyper spectral CO2 detector such as spectral resolution,sampling ratio and sign-to-noise ratio (SNR)on CO2 detection are analyzed. <br> Typical characteristics of hyper spectral CO2 detector on TANSAT are grating spectrometer and array-based detector.To achieve the column averaged atmospheric CO2 dry air mole fraction (X CO 2 )precision re-quirements of 1×10 -6 -4×10 -6 ,hyper spectral CO2 detector should provide high resolution at first to re-solve CO2 absorption lines from continuous spectra of reflected sunlight.Compared to a variety of simula-ted spectral resolutions,the spectral resolution of hyper spectral CO2 detector on TANSAT can resolve CO2 spectral features and maintain the moderate radiance sensitivity.Since small size array detector-based instruments may suffer from undersampling of the spectra,influences of spectral undersampling to CO2 ab-sorption spectra are studied,indicating that sampling ratio should exceed 2 pixels/FWHM to ensure the accuracy of CO2 spectrum. <br> SNR is one of the most important parameters of hyper spectral CO2 detectors to ensure the reliability. SNR requirements of CO2 detector to different detection precisions are explored based on the radiance sen-sitivity factors.Results show that it is difficult to achieve SNR to detect 1×10 -6 -4×10 -6 CO2 concentra-tion change in the boundary layer by solar shortwave infrared passive remote sensing,limited by the in-strument development condition and level at present.However,the instrument SNR to detect 1% change in the CO2 column concentration is attainable.These results are not only conductive to universal applica-tions and guides on developing grating spectrometer,but also helpful to better understand the complexity of CO2 retrieval.