Investigations into photogrammetric potentials of medium and high resolution digital camera systems

Investigations into Photogrammetric Potentials of Medium and High Resolution Digital Camera Systems Digital cameras have an important place in Digital Imaging Technologies. In addition, digital cameras are extensively used both in Remote Sensing and Photogrammetiy science as a tool of data acquisition. So as to define the technical performance and compare with the other technologies digital cameras must be tested. Calibration that can be defined as introducing calibration parameters of any camera system is used to designate metric potential, investigate and correct the systematic errors of camera systems. In addition to their metric performance, the radiometric performance of these digital camera systems must be considered. In this contribution, medium and high resolution camera systems' geometric and radiometric potentials were considered. The digital camera systems Nikon E2/E2s, which have medium and the Kodak DCS460 which have high resolution capacities have been taken into consideration for this study. In addition to the mentioned camera systems, high resolution camera systems Nikon Coolpix 990, Olympus-El 0 and medium resolution camera system Rollei D7 Metric have been used in order to compare with each other. Geometric tests of these camera systems were carried out both for selected building models in real areas and for the control areas set up in laboratory. In the course of the study, adequate number of control points are situated and coordinated in the control areas by geodetic methods. The image coordinates of the same control points were measured by using photogrammetric software's. To evaluate geometric performance of the digital camera systems four different mathematical models were considered. These are the mathematical method of Elcovision 10 software, Direct Lineer Transformation Method (DLT), Bundle Adjustment with Additional Parameters Method and the mathematical method of BLUH software. All used models are based on colinearity equations, but differ from determining parameters in containing systematic error sources. By comparing the results gotten from these models the best model from the point of view geometric performance have been tried to be found out. Besides, the cameras, which have different geometric resolution, were compared with each other from the standpoint of geometric accuracy. To designate radiometric properties of the used digital cameras, reactions of the cameras to the absolute white and black environment were determined and then dead pixels were eliminated. Key Words: Digital Photogrammetry, Digital Camera, Calibration, Geometric Accuracy, Radiometric Properties, DLT Method, Bundle Adjustment Method VII