非均匀大气下跑道视程测量的多次散射修正OA

To comprehensively consider the influencing factors of Runway Visual Range(RVR)measure-ment and to fill the research gap in RVR scattering correction under inhomogeneous atmospheric condi-tions,this study investigated the influence mechanisms of atmospheric inhomogeneity and multiple scatter-ing on RVR measurement correction under low-visibility conditions.First,a segmented inhomogeneous atmospheric model was established.By combining the empirical relationship between extinction coefficient and visibility,RVR was calculated based on Koschmieder's law and Allard's law,respectively.Second,a multiple-scattering correction factor was introduced for both laws,and its effects on the response relation-ships of the two laws,the transition between edge lights and center-line lights,and the subsequent deter-mination of operational categories(CAT)were systematically analyzed.Finally,measured lidar echo data were utilized to retrieve extinction coefficient profiles,thereby validating the analytical results obtained from the proposed model.The results demonstrate that under horizontally inhomogeneous atmospheric conditions,compared with the original values,the introduction of the multiple-scattering correction yields the following key outcomes:in an increasing fog field,the reported RVR value decreases by an average of 428 m,and the CAT I/II category boundary retreats 107 m toward the runway threshold,thereby effec-tively correcting the distal shift bias present in the original results.In a decreasing fog field,the reported RVR decreases by an average of 79 m,and the operational category recovers from the original result of CAT I being maintained throughout the entire runway segment to the true trend of CAT II transitioning to CAT I.In summary,the multiple-scattering correction can effectively eliminate the systematic overestima-tion of RVR and restore the operational category determination to a reasonable level.This study provides a valuable reference for RVR assessment in airport operational support under low-visibility weather condi-tions.