3D modeling of historical measurement instruments using photogrammetric and laser scanning techniques

Historical artifacts are the common heritage of all humanity. Therefore, preserving historical artifacts is very important in keeping the cultural heritage alive and passing it on to generations. One of the most effective methods used in documentation studies is the photogrammetric method. Although these methods are widely used, they are changing and developing day by day by gaining momentum with technology development. Laser scanners, which have entered our lives with the development of technology, have provided new opportunities to three-dimensional (3D) modeling and have become a frequently used method because they can model even objects with complex geometry in a short time and in a practical way. In this study, Theodolite (18th century), Sextant (18th century) and Graphometer (18th century) instruments on display at the Istanbul Technical University (ITU) Geomatics Engineering Department Historic Measurement Instruments Museum were modeled using photogrammetric and laser scanning methods. To compare the accuracy of the models, caliper measurements were taken from specific points of the instruments used in the modeling. Measurements were made on the models using the same points, and a comparison was made on the findings.