Development of remote sensing system using an unmanned helicopter (Part 1) - GIS mapping for agricultural land information

摘要

The objective of this study is to develop a system that can generate a map regarding crop status obtained by an imaging sensor mounted on an unmanned helicopter. As for the unmanned helicopter used in this research, an RTK-GPS was adopted as a positioning sensor, and an inertial sensor that provides posture (roll and pitch angles) was installed in the helicopter. Moreover, a geomagnetic direction sensor (GDS) that outputs an absolute direction is also equipped with the helicopter. When obtaining the image by the imaging sensor on the helicopter, some distortions caused by change of helicopter's posture arise in the image. In order to remove this distortion, geometric correction by converting from image coordinate to global coordinate is badly needed. But there are errors in posture data. Particularly, large GDS error was caused by warp of geomagnetism surrounding the helicopter. Therefore the method of correction of GDS errors was developed in the study. As the result, it was possible to generate a map including maximum error of 41 cm using the image taken from the helicopter.