Airborne geophysical survey: Western Maine

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）由航空器搭载的仪器沿飞行航线采集，同步记录磁场强度数值与位置信息。在航空磁测发展初期，此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重构成果，其生成途径包含两种：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以获取对应的磁场强度数值。本数据集所收录的数值包括纬度、经度与地图坐标系下的航磁强度数值。