太阳光在地球大气传输过程中产生的散射会呈现出固有的偏振特性，因此利用大气散射偏振态分布特性及其与太阳照射几何以及地表观测几何之间存在的对应关系，为地球大气层内导航提供了可能。然而因气象变化造成的大气组分改变会直接影响光散射分布，从而影响基于偏振态分布的方向定位精度，因此在偏振导航实际应用过程中，其方向指引精度受大气状况影响较大。为研究不同气象条件下天空偏振态变化内在机理，研制了一台天空可见-近红外光谱偏振态自动测量仪。该仪器可按需进行定时段、定天区、多天候天空光谱偏振态测量，采用分时偏振同时分谱非成像测量体制。仪器主要由偏振分析模块、偏振检测方位定位驱动电机、微型光谱仪、GPS定位模块、嵌入式采集控制模块、二维载重转台等部分组成，光谱范围为390～960 nm，光谱分辨率为1.5 nm，观测视场为3°，光谱线偏振度测量精度优于98.85%，偏振角测量精度优于0.1°，单点观测时间小于9 s。经实验室定标和外场测试，表明该仪器可在多种气象条件下稳定观测天空光谱偏振态，其测量数据可用于天空偏振态影响机理相关研究。

The scattering of sunlight during its transmission process in the earth's atmosphere has inherent polarization characteristics. Therefore, utilizing the polarization state distribution of atmospheric scattering and its corresponding relationship with the geometry of solar irradiation and surface observation, provides the possibility for navigation in the earth's atmosphere. However, the change of atmospheric composition caused by meteorological changes can directly affect the distribution of light scattering, further affecting the positioning accuracy based on the distribution of polarization state. So, in practical application, the accuracy of polarization navigation guidance is greatly affected by atmospheric conditions. In order to study the inherent mechanism of sky polarization state change under different meteorological conditions, an automatic measuring instrument for sky VIS-NIR spectrum polarization state was developed. The instrument can measure the spectral polarization state of the sky in a fixed time period and in a fixed sky area according to the settings, and adopts a non-imaging measurement method of time division polarization and simultaneous spectrum division. The instrument is mainly composed of a polarization analysis module, a positioning drive motor, a miniature spectrometer, a GPS positioning module, an embedded acquisition control module, a 2-D load turntable and other parts. Its spectral range is 390-960 nm, with spectral resolution of 1.5 nm, observation field of 3°, spectral linear polarization measurement accuracy better than 98.85%, polarization angle measurement accuracy better than 0.1°, and single-point observation time less than 9 seconds. Throught laboratory calibration and field tests, it has been verified that the instrument can stably observe the sky spectral polarization state under various meteorological conditions, and its measurement data can be used to study the influence mechanism of sky polarization state.