AI 中文总结
本研究量化了磁异常随传感器高度的衰减，发现无人机磁测在数米高度仍可检测场地，但细节严重退化，建议对小型目标采用亚米级至低米级高度以获取更高解释精度。
AI 中文摘要
磁法测量在考古学中被广泛用于通过检测过去人类活动引起的地球磁场变化来揭示埋藏特征。然而，随着传感器高度的增加，地下源产生的磁异常会减弱并变宽，这对地面和空中（无人机）测量都构成了挑战。本研究使用一个均匀磁化的圆形窑炉的全合成模型，以及对挪威中部Storbekken 1铁生产场地实测磁通门数据的向上延拓，量化了这种随高度变化的信号和空间分辨率损失。合成实验表明，一个埋深0.3米、直径2米、厚1米的磁化圆柱体，在2米传感器高度处仅保留其近地表（0.2米）峰值幅度的约11%，在4米处仅保留约3%。在混合实验中，复合炉异常的数百纳特幅度在2至3米高度处衰减至数十纳特，而明显的瓣状特征合并为宽泛的低对比度特征。结果表明，无人机磁测在场地检测和圈定方面，在详细场地内部形态已严重退化的高度上仍可保持有效。对于小型或微弱的考古目标，亚米级至低米级传感器高度可提供显著更多的解释细节。近期关于无人机系统噪声的现场证据进一步表明，实际可探测性不仅取决于源距离衰减，还取决于平台配置和采集策略。所得的衰减曲线和形态观察为规划考古和浅层地球物理无人机磁测调查提供了可迁移的指导。
英文摘要
Magnetic surveys are widely used in archaeology to reveal buried features by detecting variations in the Earth's magnetic field caused by past human activities. However, as sensor height increases, magnetic anomalies produced by subsurface sources weaken and broaden, posing challenges for both ground-based and aerial (UAV) surveys. This study quantifies that altitude-dependent loss of signal and spatial definition using a fully synthetic model of a uniformly magnetized circular kiln together with upward continuation of measured fluxgate data from the Storbekken 1 iron-production site in central Norway. The synthetic experiment shows that a 2 m diameter, 1 m thick magnetized cylinder buried 0.3 m below ground retains only about 11% of its near-surface (0.2 m) peak amplitude at 2 m sensor height and about 3% at 4 m. In the hybrid experiment, composite furnace anomalies of several hundred nanoteslas collapse to tens of nanoteslas by 2 to 3 m, while distinct lobes merge into broad, low-contrast features. The results show that UAV-borne magnetometry can remain effective for site detection and delineation at elevations where detailed intra-site morphology is already strongly degraded. For small or subtle archaeological targets, sub-metre to low-metre sensor heights provide substantially greater interpretative detail. Recent field evidence on UAV-system noise further indicates that practical detectability will depend not only on source-distance attenuation but also on platform configuration and acquisition strategy. The resulting attenuation curves and morphological observations provide transferable guidance for planning archaeological and shallow-geophysical UAV magnetic surveys.
