Airborne geophysical survey: Advance, Missouri

Aeromagnetic data were collected along flight lines by instruments in an
aircraft that recorded magnetic-field values and locations. In the earlier
days of surveying, the only way to represent this data was to generate an
analog map with contour lines. This dataset is a representation of the
digitized contour lines either by following the lines or by choosing the
intersection of the contour and flight-line to create a value of the magnetic
field. The values presented are latitude, longitude, and map magnetic-field
values.

航空磁力数据（aeromagnetic data）由搭载于航空器的仪器沿飞行航线采集，同步记录磁场强度与位置信息。在航磁测量的早期阶段，该类数据唯一的可视化方式为生成带等值线的模拟地图。本数据集为数字化等值线的成果呈现，其生成途径包括沿等值线追踪采样，或选取等值线与飞行航线的交点以获取磁场强度数值。所提供的数值包含纬度、经度与航磁场强数值。