AI 中文总结
该研究针对CSIRO默奇森射电天文台的RFI问题，提出基于GFS数据的对流层波导预测方法，结合GBM模型提升预测性能，可用于自适应观测调度及实时预测服务。
AI 中文摘要
对流层波导会将地面射频干扰（RFI）传输数百公里，到达位于Inyarrimanha Ilgari Bundara的澳大利亚联邦科学与工业研究组织（CSIRO）默奇森射电天文台（Murchison Radio-astronomy Observatory, MRO）的ARQZWA区域。本文提出一种基于GFS数据推导的垂直折射率廓线的波导预测方法，利用88 MHz至2.68 GHz频段内7年的连续频谱监测数据对该方法进行验证。针对每个发射机，采用Rec ITU-R P.452-16计算100 MHz以上频率到该站点的基本传输损耗，采用Rec ITU-R P.1812-6计算100 MHz以下频率的基本传输损耗，计算过程基于Copernicus GLO-90地形数据，且每个时间步长均由GFS推导的沿路径的折射率递减率驱动。模型技能采用分层AUC评估，分层维度为月份和三小时时段，中位分层AUC为0.724，25个置信区间中有24个排除了随机概率的可能。基于4个试点月份得到的时间百分比校准结果，无需重新调整即可直接应用于完整数据集，且在3天的预测提前期内技能保持稳定。采用相同物理特征并增加波导走廊连通性指标的池化GBM模型，在全部25个信道上的平均测试AUC达到0.806，在分析预测器本身具备技能的16个信道上的平均测试AUC为0.799。现场LTE小区解码结果证实了归因：86%-97%的超视距小区检测结果落在标记事件时段内，该范围涵盖4个受监测的LTE信道，且解码得到的网络标识与许可记录一致。162 MHz处的船舶自动识别系统（AIS）接收信号为甚高频（VHF）提供了地面真值，每个信号来自已知海上位置的自定位12 W发射机。调频（FM）信道仅保留微弱技能，远低于波导信道，在排除波导、偶发E层和飞机散射的影响后，本文将其事件归因于近阈值本地源。该方法可实现自适应观测调度，避开受预测波导影响的频率，并为天文台提供实时预测服务。
英文摘要
Tropospheric ducting transports terrestrial RFI over hundreds of kilometres into the ARQZWA at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory. We present a ducting prediction method based on vertical refractivity profiles derived from GFS data, validated against seven years of continuous spectrum monitoring between 88 MHz and 2.68 GHz. Per-transmitter basic transmission loss to the site is computed with Rec ITU-R P.452-16 above 100 MHz and Rec ITU-R P.1812-6 below it, over Copernicus GLO-90 terrain, driven at each timestep by the GFS-derived refractivity lapse along the path. Skill is scored as a stratified AUC, computed within month and three-hour strata. The median stratified AUC is 0.724 and 24 of 25 confidence intervals exclude chance. A time-percentage calibration derived from four pilot months transfers without retuning to the full record, and skill is flat through three days of forecast lead. A pooled GBM on the same physical features, augmented by a duct-corridor connectivity metric, reaches a mean test AUC of 0.806 over all 25 channels and 0.799 over the 16 on which the analytical predictor is itself skilled. In-situ LTE cell decoding confirms attribution: 86-97% of over-the-horizon cell detections fall within flagged event hours, the range spanning the four monitored LTE channels, and the decoded network identities match the licensing records. Ship AIS receptions at 162 MHz, each a self-located 12 W transmitter at a known sea position, provide VHF ground truth. The FM channels retain only weak skill, far below the ducting channels, and we attribute their events to near-threshold local sources after excluding ducting, sporadic-E and aircraft scatter. The method enables adaptive scheduling of observations away from frequencies affected by forecast ducting, and drives a live forecast service at the observatory. (Abstract abridged for arxiv)
Comments20 pages, 18 figures
