Volume XLII-2
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-2, 441-448, 2018
https://doi.org/10.5194/isprs-archives-XLII-2-441-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-2, 441-448, 2018
https://doi.org/10.5194/isprs-archives-XLII-2-441-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

  30 May 2018

30 May 2018

PROTOTYPIC DEVELOPMENT AND EVALUATION OF A MEDIUM FORMAT METRIC CAMERA

H. Hastedt1, R. Rofallski1, T. Luhmann1, R. Rosenbauer2, D. Ochsner2, and D. Rieke-Zapp3 H. Hastedt et al.
  • 1Jade University of Applied Sciences, Oldenburg, Germany
  • 2ALPA Capaul & Weber AG, Zurich, Switzerland
  • 3AICON 3D Systems GmbH, Germany

Keywords: photogrammetry, accuracy, metric camera, calibration, length measurement error, large volume metrology

Abstract. Engineering applications require high-precision 3D measurement techniques for object sizes that vary between small volumes (2–3 m in each direction) and large volumes (around 20 x 20 x 1–10 m). The requested precision in object space (1σ RMS) is defined to be within 0.1–0.2 mm for large volumes and less than 0.01 mm for small volumes. In particular, focussing large volume applications the availability of a metric camera would have different advantages for several reasons: 1) high-quality optical components and stabilisations allow for a stable interior geometry of the camera itself, 2) a stable geometry leads to a stable interior orientation that enables for an a priori camera calibration, 3) a higher resulting precision can be expected. With this article the development and accuracy evaluation of a new metric camera, the ALPA 12 FPS add|metric will be presented. Its general accuracy potential is tested against calibrated lengths in a small volume test environment based on the German Guideline VDI/VDE 2634.1 (2002). Maximum length measurement errors of less than 0.025 mm are achieved with different scenarios having been tested. The accuracy potential for large volumes is estimated within a feasibility study on the application of photogrammetric measurements for the deformation estimation on a large wooden shipwreck in the German Maritime Museum. An accuracy of 0.2 mm–0.4 mm is reached for a length of 28 m (given by a distance from a lasertracker network measurement). All analyses have proven high stabilities of the interior orientation of the camera and indicate the applicability for a priori camera calibration for subsequent 3D measurements.