Authors : E. Emetere Moses, M.l. Akinyemi and O. Akin-Ojo
Abstract: Estimating the aerosol optical properties over an area has been challenging due to the propagated signal from or to the satellite sensor. We propose that aerosols layer is formed in the atmosphere via reflected signals to create multipath. This act makes the satellite sensors see the superposition of multiple copies of transmitted signal which affects aerosol measurement at the long run. One of the reliable remote sensing techniques for investigating aerosol optical depth is the Multi-angle Imaging Spectro Radiometer (MISR). The MISR reanalysis is performed at the native horizontal resolution of 2°/3° longitude by 0.5° latitude and at 72 levels up to 0.01 hPa. The accuracy of MISR was investigated using mathematical experimentation. The spectral resolution of the green spectral band of the MISR corresponds to four bands (i.e., 1, 2, 3 and 6) on the MODIS. This occurrence affirms the band superposition theorem enacted in this research. This phenomenon is responsible for the inability of satellite or ground sensors to effectively measure the vertical distribution of aerosol. Five evidences of the superposition effect on satellite sensor adaptation were shown.
E. Emetere Moses, M.l. Akinyemi and O. Akin-Ojo, 2016. Effects of Band Superposition on the Satellite Imagery of Aerosol Optical Depth over West Africa. Journal of Engineering and Applied Sciences, 11: 17-22.