The Design Of The Hardware And Software Of Solar Spectrum Collecting Equipment And The Inversion Of Concentration Of NO₂ In The Atmosphere

With human's development, the environment having been seriously damaged. The atmosphere is polluted by the developed industry, as the result, so many polluting phenomenons emerged, including the acid rain. The acid rain will threat the freshwater ecosystem , the plants , the soil and even the human's survive. One of the main reason formed acid rain is the nitrogen- oxygen compound(NOx), especially the NO2.Therefore, concentration of NO2 in the atmosphere must be inspected effectively. Presently, many inspecting method have been developed, including the method of solar spectrum analyse. The sunlight, when transmitting through the atmosphere, will interact with the gas molecules. There are differences in the absorptivities of different molecule at different wavelength, which will change the solar spectrum. The NO2 , at the wavelength bound of 430-450nm, can absorb the sunlight intensively, according to the law of Beer-Bouguer-Lambert. With the law we can get the concentration of NO2 in the atmosphere by analyzing the solar spectrum.In our task, a set of equipment for collecting solar spectrum has been developed. The hardware, based on OMA(Optical Multi-Channel Analyzer), is consisted of the spectrometer, CCD detector with the driver, A/D, notebook PC etc. The software is programmed by Visual C++. With functions of single collecting, real time collecting, average collecting etc, the solar spectrum can be collected perfectly. What's more, the function of spectrum analyzing is also included in the software, with which, the concentration of NO2 in the atmosphere can be got quite easily.In the April of 2004, by the equipment, the reference solar spectrum and the sample solar spectrum were got separately inXi-Ling mountain and Cheng-Du. Then, through the two spectra, the concentration of NO2 in the atmosphere of Cheng-Du of April 25th , 2004 was gotton.Generally, the equipment, besides the features of low cost , legerity and easy operation , owns the characteristic of high precision and high collecting efficiency. In every application, the equipment has completed its tasks perfectly.