第四章距离测量( distance measure) 与直线定向( line orientation) 般在精度上: 电磁波测距EDM( electro- magnetic distance measuring 钢尺量距 (steel tape measuring) 视距法测距( stadia measurement)第四章 距离测量(distance measure) 与直线定向(line orientation) 一般在精度上： 电磁波测距EDM(electro-magnetic distance measuring) 钢尺量距(steel tape measuring) 视距法测距(stadia measurement)