Development of 3-D GIS Map Generation System Using an Unmanned Helicopter

Abstract

The objective of this study is to generate a 3D-GIS map of farm field. The survey systemwas developed based on an unmanned helicopter. An RTK-GPS was adopted as a positioningsensor, and an inertial sensor that provides posture (roll and pitch angles) was installed on thehelicopter. Moreover, a geomagnetic direction sensor (GDS) that outputs absolute direction is alsoequipped with the helicopter. And a laser scanner was adopted to detect the distances between ahelicopter and ground. This leaser scanner provides a two-dimensional range data.Tthe sensor was attached on a pan-head can rotate in pan and tilt directions. Pan-head angles can be measured bytwo rotary encoders with 0.001 rad of resolution. Therefore, field elevation was sensed by rotatingthe pan head during hovering of an unmanned helicopter.<br><br>In order to develop the precise survey system, the offset due to misalignment of sensor attachmentwas identified by measuring already measured position. And, because the GDS is influenced by amagnetic field surrounding the GDS, the direction data includes significant error. The GDS bias wasalso compensated by a FOG.<br><br>Finally, the developed system accuracy was evaluated by the field test and express a farm field with3D-GIS map. The 3D-GIS map was generated by transforming a laser scanner coordinate to globalcoordinate using a helicopter position and posture data.