Error analysis of multi-wavelength sun photometry |
| |
| Authors: | Glenn E Shaw |
| |
| Institution: | (1) Geophysical Institute, University of Alaska, 99701 Fairbanks, Alaska, USA |
| |
| Abstract: | The error terms involved in precision multi-wavelength sun photometry, as used to study atmospheric aerosols, are analyzed. The error terms treated include instrumental errors, calibration errors, and errors imposed by the atmosphere. It is shown that in order to derive accurate aerosol parameters, one must exercise great care in the photometer calibration. A procedure for accurate calibration is described, based on an intercalibration between extrapolations of the extraterrestrial solar spectral irradiance and irradiance of a standard lamp. Methods are described to assess, and reduce, uncertainties brought about by diffuse radiation in the photometer's field of view, temporal variations in aerosol optical depth, and gaseous absorption features at the operating wavelength. It is shown that if care is taken sun photometry can be used to derive monochromatic aerosol optical depth to an accuracy of several thousandths. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
