This paper describes cable height measurement & database system using a single camera and 3D environmental model. The proposed Mobile Mapping System (MMS), featuring the carrier phase D-GPS/DR(Dead Reckoning)combined navigation system and the GPS-Gyro/IMU(Inertial Measurement Unit), performs highly accurate positioning performance in centimeters and posture estimation at 0.073[deg](1σ) for heading, 0.064[deg](1σ) for pitch and 0.116[deg](1σ) for roll. As a result of the evaluation test, the difference between the conventional method and the proposed one was less than 10 [cm]. Moreover, the aerial cable database, which can be made using the obtained 3D data, is proved to be valid and effective for the continuous aerial cable maintenance work.