Airborne geophysical survey: Lawrence County, South Dakota

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.本数据集的航空磁测数据由机载仪器沿飞行航线采集，同步记录了磁场强度值与定位信息。在早期航空磁测作业中，对此类数据进行可视化呈现的唯一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成果，其生成方式包含两类：一是沿等值线轨迹进行采样，二是选取等值线与飞行航线的交点并提取对应磁场强度值。本次公开的数据包含纬度、经度以及等值线图对应的磁场强度值三类字段。