Multi-wavelength IR method for monitoring air pollution in cities

In this work we address the problem of air pollution in modern cities. We propose a method for detection and analysis of evaporation (H2O), carbon dioxide (CO2), carbon monoxide (CO) and methane (CH4) which are the typical components of exhaust gases produced by the gasoline vehicles. The method is based on infrared multi-wavelengths absorption in the range of 1.3-2.3 μm and can be implemented by using multi waves array of light emitting diodes (LEDs). The proposed approach allows several absorption spectra to be covered by one LED absorption line, thus the number of used LEDs should be not less than the number of considered absorption lines. The simulation was done for a 6-element multi-wavelengths LED array. We demonstrate that the method is highly relevant for the application to open-path detectors where the radiation source and the receiver are located at a distance of tens of meters from each other.