考虑大气透射仪的光源不稳定性以及光学准直及大气环境的动态变化均会对其测量精度产生影响,本文在高精度导轨上设计了多点移动大气透过率测量系统,以便提高其大气透过率及消光系数的测量精度。该系统采用可移动测试平台,运用多点移动测量的方式测量大气透过率及消光系数。基于理论比较了多点移动大气透过率测量方法与传统大气透射仪测量方法的测量精度,证明了该系统的测量精度高于传统大气透射仪。将该系统与经过良好校正的Skopograph II型大气透射仪在大气环境模拟舱进行了较长时间的对比验证。结果表明,两套系统具有很好的相关性,91.93%的数据对偏差在10%以内,相关系数达0.985 7。在低能见度条件下,多点移动大气透过率测量系统的测量稳定性优于传统大气透射仪。得到的结果显示:该系统能够满足大气透过率和消光系数测量对准确性、稳定性和一致性的要求。
In consideration of the instability of light sources and the effects of optical collimation and atmospheric dynamic change of an atmospheric transmissometer on its measuring accuracy, this paper designs a new multi-point mobile atmospheric transmittance measurement system on a high precision guide rail. This system is based on a mobile measuring platform, and uses the multi point movement model to measure the atmospheric transmittance and extinction coefficient. The measuring accuracies from the proposed multi-point mobile atmospheric transmittance measurement method and from tradi- tional atmospheric transmittance measurement method were analyzed and compared in theory, and the results show that the accuracy of the former is better than that of the latter. Moreover, the multi- point system and Skopograph Ⅱ transmissometer were compared in a simulation chamber of atmos-pheric environment. The results demonstrate that two systems have an excellent correlation, in which 91.93% of the data is within 10% deviation, and the correlation coefficient is 0. 985 7. In low-visibili- ty conditions, the stability of the multi-point system is better than that of traditional transmissome- ter. It concludes that the multi-point system satisfies the demands of atmospheric transmittance and extinction coefficients for the accuracy, stability and the veracity.