提出了一种利用单一可调谐外腔二极管激光(ECDL)及谐波探测技术对甲烷进行现场、实时遥感探测方案。通过理论推导计算出该方案在甲烷2ν3吸收带的R6е吸收线上理论最小可探测路径 积分浓度为87×10 -9。根据该方案建立了实验系统，实验结果验证了该方案的可行性并估算出实验最小可探测甲烷的路径 积分浓度为420×10 -9。

This article describes the design and testing of a laboratory prototype single diode laser system for remote detection of methane gas using harmonic detection. Harmonic signals are contained within radiation backscatter from topographic targets. A function of detected gas concentration depends on these harmonic signals is given by theoretical derivation. Base on it, minimum theoretical detection limit for methane is calculated to be about 87×10 -9 and the minimum measurable path-integrated concentration is estimated to be about 420×10 -9 by experimentation with real situation in laboratory at 2ν 3-band R(6) line of methane.