扩展多波长偏振测量的太阳—天空辐射计观测网

太阳辐射和大气气溶胶的地基遥感观测在气候变化、大气环境和对地观测等领域有重要意义。结合多波长偏振测量技术在气溶胶观测中的应用,本文介绍了在中国典型区域建立的太阳—天空辐射计观测网SONET(Sunsky radiometer Oberservation NETwork)。主要内容包括:(1)多波长偏振太阳—天空辐射计的参数、基本原理和功能,以及据此建立的中国区域太阳—天空辐射计观测网及其站点的基本情况;(2)太阳直射、太阳主平面和平纬圈几何条件下,太阳—天空辐射和偏振的观测模式及其测量参数;(3)针对气溶胶、水汽等大气成分观测发展的太阳直射辐射、天空光辐亮度、线偏振度等观测量的定标和数据处理方法,并给出在晴朗和灰霾等天气下的SONET观测结果示例;(4)基于在SONET典型站点连续的较长期遥感观测,初步建立了城市、乡村和灰霾情况下的整层大气气溶胶参数模型。在扩展多波长偏振测量的基础上,SONET还发展了自动观测、快速数据处理、定期标定和维护等观测网运行关键技术,可为典型大气气溶胶模型构建、卫星气溶胶产品反演和验证、大气环境遥感监测等应用提供支撑。

Sun-sky radiometer observation network with the extension of multi-wavelength polarization measurements

Focusing on the important role of ground-based sun radiation and aerosol observation in the fields of climate change, atmospheric environmental monitoring, and earth observation, we established a Sun-sky radiometer Observation NETwork (SONET) in typical Chinese regions by applying multi-wavelength polarimetric observation techniques. We present the following in this paper: (1) the characteristics, measurement, principles, and functions of the multi-wavelength polarization radiometer and the establishment of SONET in typical Chinese regions with a brief introduction of the observation sites; (2) observation patterns of sun-sky radiation and polarization as well as measurement parameters under direct sun, solar principal plane, and almucantar geometries; (3) calibration of solar irradiance, sky radiance, and degree of linear polarization measurements and data processing methods for aerosol and water vapor, with illustrations of typical SONET observation under clear and hazy conditions; (4) establishment of urban, rural, and haze aerosol type models of the total column atmosphere based on long-term continuous remote sensing observation in typical sites in China. On the basis of extension of multi-wavelength polarization measurements, SONET was employed to develop operational techniques for the network of sun-sky radiometers, including automatic observation, fast data processing, and regular calibration and maintenance, which contribute to the construction of atmospheric aerosol type models, retrieval and validation of satellite aerosol products, and remote monitoring of the atmospheric environment.