Aerial Photogrammetric Targeting and Ground Control Surveys

To ensure the geolocation accuracy of imagery, this Branch conducts various types of control surveys for aerial survey targets and natural control points. In earlier operations, base stations had to be set up with long-duration static observations, resulting in time-consuming and complex procedures. Since 2014, we have adopted the National Real-Time Kinematic Satellite Positioning System (e-GNSS) developed by the National Land Surveying and Mapping Center, Ministry of the Interior. This system enables the calculation of high-precision coordinates within seconds to a few minutes, significantly reducing operational time.

Starting in 2018, the LEICA GS18 GNSS receiver has been used, incorporating wireless transmission and Virtual Reference Station (VRS) technology. This has greatly improved the flexibility and convenience of field surveys, enhancing both operational efficiency and data quality. Field operations include the installation of aerial survey targets and identification of natural control points, which serve as reference data for aerial triangulation and orthorectification. These efforts ensure the accuracy and consistency of subsequent mapping and applications.

Aerial Survey Target Control Survey

Natural Point Control Survey