Infrared spectra in air pollution research and monitoring from space: A review

Infrared (IR) wavelengths are applied in various fields such as detection of invisible matter which can generate irradiative energy from its body as well as analysis of chemical structures and materials, atmospheric observation, military, and medical. Atmospheric stagnation and continuous inflow of pollutants are introduced because of the extreme climate change caused by the increase in air pollutants such as greenhouse gases (GHGs) and particulate matter (PM). As a result, air pollutants are increasingly concentrated, but the technology to measure them is limited based on the current point of care. Satellite remote sensing by IR wavelength bands in Earth's orbit can overcome points of care and track their changes. It is also one of the approaches that can effectively monitor the distribution of GHGs such as carbon dioxide and methane and PM simultaneously in real-time because of high spatial and temporal resolution. It is expected to estimate the causes of induction and increase of GHGs with comparative accuracy, and many countries adopt this measurement method. Furthermore, it can sufficiently complement the onsite network as it can measure changes in GHGs and PM relatively accurately in most of the earth, including areas that are difficult to access, unlike ground and air-based measurement techniques that can only observe in limited areas. This article summarizes the current research and issues applying satellite remote sensing technology for measuring them, especially GHGs, based on the IR spectrum and hyper-spectral method for analyzing acquired data.