ABSTRACT
Based on the object's polarization effects, polarization is a newly emerging method in the field of remote sensing. Both objects and atmosphere have polarization effects, however, the atmosphere's polarization effects are much stronger than that of objects'. Consequently, atmosphere polarization effects will interfere or even cover objects' when observing with sensors. How to maximally eliminate the polarized effects generated by the atmosphere is a crucial problem in polarization remote sensing. Atmospheric neutral point is an area where the degree of atmosphere polarization is near to zero; therefore, if sensors are set up in this area, atmosphere polarization would be greatly eliminated, which is the main content of separating the effects between objects and atmosphere by its neutral point method. In this paper, after processing and analyzing the experimental data got from the first polarization remote sensing flight experiment with atmosphere neutral point, the degree of polarization images captured in neutral and non-neutral point area were obtained, and it can be seen that the main value of polarized degree of images got in neutral point area was obviously smaller than that in non-neutral point area. The results showed that the theory mentioned above was logical and practical. An innovation in our study is that the requirements needed in polarization remote sensing flight with neutral point were clarified. In the meantime, a qualitative conclusion was drawn that observing with longer wavelength is more applicable to polarization remote sensing.
ABSTRACT
Ocean aerosol is an important component of troposphere aerosol, playing an important role in the global radiative balance and global climate change. To evaluate the direct and indirect radiative effects of aerosol needs deep research on aerosol properties. Multi-angular polarization provides a new method to retrieve aerosol optic and microphysical properties of aerosol. On the basis of the research on optic properties of ocean aerosol at the wavelength of 550 and 860 nm, a vector radiative transfer model was used to simulate the reflectance and polarized reflectance at the top of atmosphere. The sensitivity of reflectance and polarized reflectance to underlying surface, viewing azimuth and aerosol optic depth are evaluated. The simulation results show that the multi-angular polarization information could effectively provide information about the ocean aerosol, which suggests a useful way for ocean aerosol retrieval. Based on the studies of sensitivity, the theory of using multi-angular polarized remote sensing data to retrieve aerosol information is proposed.
