大气CO2是一种温室气体, 在气候变化等领域起着关键作用。基于NDIR技术研制了可用于探测大气CO2垂直廓线的无线传感系统。系统采用电调制型的红外辐射光源、双通道探测器并结合超低功耗单片机实现大气CO2信号的采集与控制。提出采用调制信号周期内扣除信号起伏与背景噪声的方法, 使得本系统具有0.29%的相对测量误差。通过分时工作的方式解决了数字式无线电探空仪中高频发射机对CO2检测电路运算放大器的电磁辐射干扰, 进而实现了气象探空仪与小型化的CO2探测系统的高度集成。通过与地面LI-COR LI7500对比分析, 两者表现出较好的一致性, 24 h测量数据的相关性达0.89, 表明所研制的探测系统的稳定性与准确性。为实现大气CO2垂直廓线的探测提供一种选择。

The atmospheric carbon dioxide(CO2) is a greenhouse gas which plays a dominant role in climate changes and also in some other fields. The remote sensing system for vertical profiles of atmospheric CO2 was based on non-dispersive infrared gas detection technology, which can transmit data by wireless. The modulated infrared radiation source and dual-channel detector were employed in the system which take advantage of ultra-low consumption MCU to realize automatic control and acquisition. The method of deducting the fluctuation and background noise of signal was proposed, which made the relative error at 0.29% of the detection. And the time-sharing operation mode was adopted to resolve electromagnetic interference(EMI) from high frequency transmitter of radio sounding to the operational amplifier of the CO2 detection. The digital radio sounding of widely used in meteorology and CO2 detection were integrated highly. The comparison analysis between self-made CO2 remote sensing system and LI-COR LI7500 were carried out, preliminary results show that the variation trends of atmospheric CO2 have good consistency from the two detection systems; the correlation coefficient was 0.89 from 24 hours data. It can be indicated that the self-made system has good constancy and accuracy. The self-made system offers another choice to exploit to measure the vertical profiles of atmospheric CO2.