DIRECT GEOREFERENCING : A NEW STANDARD IN PHOTOGRAMMETRY FOR HIGH ACCURACY MAPPING
Other literature type
(issn: 2194-9034, eissn: 2194-9034)
Direct georeferencing is a new method in photogrammetry, especially in the digital camera era. Theoretically, this method does not
require ground control points (GCP) and the Aerial Triangulation (AT), to process aerial photography into ground coordinates.
Compared with the old method, this method has three main advantages: faster data processing, simple workflow and less expensive
project, at the same accuracy. Direct georeferencing using two devices, GPS and IMU. GPS recording the camera coordinates (X, Y,
Z), and IMU recording the camera orientation (omega, phi, kappa). Both parameters merged into Exterior Orientation (EO)
parameter. This parameters required for next steps in the photogrammetric projects, such as stereocompilation, DSM generation,
orthorectification and mosaic. Accuracy of this method was tested on topographic map project in Medan, Indonesia. Large-format
digital camera Ultracam X from Vexcel is used, while the GPS / IMU is IGI AeroControl. 19 Independent Check Point (ICP) were
used to determine the accuracy. Horizontal accuracy is 0.356 meters and vertical accuracy is 0.483 meters. Data with this accuracy
can be used for 1:2.500 map scale project.