Airborne geophysical survey: Cardareva area, 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，同步记录磁场强度值与点位坐标。在早期勘探阶段，该类数据的唯一可视化表达方式为绘制带有等值线的模拟地图。本数据集为数字化等值线的成果表达，其生成方式分为两种：一是沿等值线进行数字化追踪，二是选取等值线与飞行航线的交点以获取对应磁场数值。数据集中包含的字段为纬度、经度与成图磁场数值。