论述了在大气二氧化碳(CO2)探测中使用高分辨率红外光谱的必要性，并通过模拟计算，分析了天基高精度大气CO2探测所需要的工作波段、光谱分辨率和信噪比(SNR)等参数。以此为基础，介绍了针对这些参数研制的空间外差CO2探测仪样机，并通过实验室Mg灯观测结果，对仪器样机的分辨率进行了验证。最后利用辐射传输软件LBLRTM，结合准实时的美国国家环境预报中心(NCEP)再分析数据对地面观测光谱进行了精确的模拟。通过将模拟光谱与仪器实测光谱进行对比，得到了较好的匹配结果。该结果表明，空间外差CO2探测仪可以获得大气CO2的精细吸收结构，其观测数据能够满足大气CO2探测的要求。

The necessity of using high-resolution near infrared spectra in space-based atmospheric CO2 detection is discussed. According to simulation results, some key parameters such as detection band, spectral resolution and singnal to noise ratio (SNR) for space-based CO2 detection are analysed. Based on these simulated parameters, a spatial heterodyne spectroscopy (SHS) prototype instrument is introduced. Then this prototype instrument′s spectral resolution and abilities in CO2 detection are verified by laboratory and out-door experiments. Using LBLRTM software and near-real-time atmospheric parameters acquired from National Centers for Environmental Prediction (NCEP), the ground-based observation data of the instrument is simulated. The comparison between simulation results and SHS prototype instrument′s measurements shows a good fit. It is proved that the SHS prototype instrument is very sensitive to atmospheric CO2 absorption, and the instrument′s measurements could be used for space-based atmospheric CO2 detection.