Aerial imaging field

　　　　The basic principle of aerial photogrammetry single photo mapping is the perspective transformation of the central projection, and the basic principle of stereo mapping is the geometric reversal of the projection process. The operations of aerial photogrammetry are divided into field and internal operations.

　　Field business includes:

　　① Joint measurement of photo control points. Photo control points are generally marked points placed on the ground before aerial photography. Obvious feature points on the photo (such as road intersections, etc.) can also be used. Angle measurement intersection, distance measurement wire Common measurement methods such as, leveling, elevation traverse, etc. determine its plane coordinates and elevation.

　　②Photo adjustment and drawing: through interpretation on the photo, features such as features, landforms, etc. are drawn with prescribed topographic map symbols; surveyed and mapped without images and newly-added important features; location names obtained through surveys should be noted.

　　③Comprehensive method of mapping, using a flat-panel instrument to plot contours on a single photo or photo map.

　　Inside business includes:

　　①Encrypted mapping control points, based on the photo control points, generally use aerial triangulation to determine the control points needed for the mapping, and check their plane coordinates and elevation.

　　②Measure and prepare the original topographic map. The basic principle of single-photographic mapping is the perspective transformation of the central projection, while the geometric reversal of the photographic process is the basic principle of stereo mapping.