Precise topographic mapping using direct georeferencing in UAV

Mapping using UAV has become very popular today due to the rapid development of electronic technology. UAVs are needed to support rapid mapping activities, such as natural disaster management, SAR applications, agricultural applications and forest fire monitoring. In addition to spatial resolution, it is also needed the accuracy of position accuracy. In general, the georeferenced process of aerial photo processing uses Ground Control Points (GCP) from GPS measurements. The disadvantage of using GCP is that GPS measurement takes a long time and the costs incurred are relatively more expensive. For this reason, certain techniques are needed to produce topographic maps with more efficient times. Direct Georeferencing on UAV is an aerial triangulation technique without the use of ground control points (GCP). Direct Georeferencing techniques will cut field surveys and produce high accuracy topographic maps. The hope is that by using this technique, the measurement of tie points can be as minimal as possible and do not even need to use a control point. This study is to evaluate Direct Georeferencing techniques in UAVs to produce accurate topographic map. Aerial photo using multi rotor UAV DJI Phantom 4 RTK/PPK. This multi rotor is equipped with a high accuracy GPS antenna and that is capable to storing GPS observation data. Photo coordinate processing using the Post Processing Kinematic (PPK) method. Accuracy of ortho rectification results of aerial photo geometry compared to check point coordinates (CP). The test results of horizontal accuracy indicate the value of 0.040 m using Circular Error 90% (CE90). Based on BIG standard the accuracy of the base map, these results can be entered on a scale of 1: 1,000 class 1. Direct Georeferencing techniques in UAVs produce high accuracy maps for relatively not extensive mapping areas.