Paper
Retrieval of High Altitude Thin Cirrus Reflectivity from Simplified Model of Earth-atmosphere System
- Authors:
- ZiJun Liao; ChunPing Yang
- Abstract
- Cirrus is composed of ice particles of the various shapes in the upper atmosphere. It has an important role in atmospheric radiation balance and the temperature feedback. Cirrus can reflect sunlight into the satellite detectors in the upper atmosphere. Therefore, cirrus reflectivity has serious noise affect for using satellite sensors to recognize the target. In this paper, combining 1.37 ?m with 0.66 ?m two-channel relationship of moderateresolution imaging spectroradiometer(MODIS) and the principle of optical remote sensing, the 1.375?m and 0.66?m two-channel algorithm to calculate the reflectivity of cirrus was deducted. In this paper further proposed a simplified model of earthatmosphere system. The model parameters of the calculation are simple and easy, and cirrus cloud reflectivity can be quickly inverted in a particular pixel region. Then a new method can be introduced to achieve algorithm by the slope of the scatter. The paper describes the detailed process how the software of ENVI extracts reflectance data from the HDF file, and discusses the principle of the algorithm and the key step in solving the inversion algorithm. The reasons and implementation for block processing scheme are analyzed, furthermore, using the method on neighborhood smoothing to process inversion results with noise is to get the more ideal cirrus reflectance data by the corresponding region of space. The inversion results show that the visible reflectance of cirrus clouds is basically less than 0.40.
- Keywords
- Cirrus cloud; Reflectivity; Remote sensing; MODIS; ENVI
- StartPage
- 34
- EndPage
- 38
- Doi