We introduce UPSim (UxNB Propagation Simulator), a ray tracing-calibrated, semi-deterministic solution for spatially consistent FR3 air-to-ground propagation modeling in uncrewed aerial vehicle (UAV) networks. Instead of launching rays for every receiver position, UPSim derives deterministic visibility regions from 3D building geometry via shadow projection. It then augments these regions with line-of-sight (LOS) state-specific and altitude-aware path loss, correlated large-scale fading, and small-scale fading. Calibration and validation against FR3 ray tracing data using the global 3D-GloBFP building dataset demonstrate that UPSim accurately reproduces empirical channel distributions. Furthermore, the resulting maps support route-based analysis of channel evolution over complex urban layouts, exposing critical trajectory-level statistics such as outage distances. Consequently, UPSim offers a highly scalable, practical middle ground between computationally expensive full ray tracing and purely stochastic channel generation for mobility-aware planning and radio-map construction in aerial access scenarios.

翻译：本文提出UPSim（UxNB传播模拟器），这是一种基于射线追踪校准的半确定性解决方案，用于无人机（UAV）网络中空间一致的FR3空对地传播建模。不同于为每个接收位置发射射线，UPSim通过阴影投影从3D建筑几何中推导确定性可见区域，并利用视距（LOS）状态特定且高度感知的路径损耗、相关大尺度衰落及小尺度衰落对这些区域进行增强。基于全球3D-GloBFP建筑数据集，与FR3射线追踪数据的校准及验证表明，UPSim能准确复现经验信道分布。此外，生成的映射图支持复杂城市布局下信道演变的路径分析，可揭示关键轨迹级统计量（如中断距离）。因此，UPSim为空中接入场景中的移动感知规划与无线地图构建，在计算成本高昂的全射线追踪与纯随机信道生成之间，提供了一种高度可扩展且实用的折中方案。