In a bid to solve the problems of the prior art, the invention provides a fully digital broadband mid-infrared calibration-free WM-LHR wavelength modulation laser heterodyne technology to detect the total amount of multi-component atmospheric gas columns. On the one hand, it directly modulates the injection current of the local oscillator laser to avoid the use of choppers; on the other hand, it can effectively eliminate the 1/f noise of the system, thus further improving the signal-to-noise ratio of the system. Com[paring the invention with prior art, it has some technical advantages in that the the injection current of local oscillator laser is directly modulated to avoid the use of chopper; on the other hand, it can effectively eliminate the 1/ f noise of the system, thus further improving the signal-to-noise ratio of the system;
Research on wavelength modulation laser heterodyne technology is carried out, and accurate forward and inverse models are established by using the measured atmospheric transmittance spectrum with high spectral resolution, so as to realize the continuous observation of the vertical distribution profile and column total of ozone and greenhouse gases.
