Volume XLII-2/W10
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-2/W10, 143-150, 2019
https://doi.org/10.5194/isprs-archives-XLII-2-W10-143-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-2/W10, 143-150, 2019
https://doi.org/10.5194/isprs-archives-XLII-2-W10-143-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

  17 Apr 2019

17 Apr 2019

COMPARISON OF DIVER-OPERATED UNDERWATER PHOTOGRAMMETRIC SYSTEMS FOR CORAL REEF MONITORING

E. Nocerino1,2, F. Neyer1,3, A. Gruen1, M. Troyer1, F. Menna4,5, A. Brooks6, A. Capra7, C. Castagnetti7, and P. Rossi7 E. Nocerino et al.
  • 1Institute of Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland
  • 2Aix-Marseille Université, CNRS, ENSAM, Université De Toulon, LIS UMR 7020, Domaine Universitaire de Saint-Jérôme, Bâtiment Polytech, Avenue Escadrille Normandie-Niemen, 13397, Marseille, France
  • 3Institute of Geodesy and Photogrammetry, ETH Zurich, 8093 Zurich, Switzerland
  • 4COMEX SA – Innovation Department, COMEX, 36 bd de l'Océan - CS 80143 - 13275 Marseille, France
  • 53D Optical Metrology (3DOM) unit, Bruno Kessler Foundation (FBK), 38123 Trento, Italy
  • 6Marine Science Institute, University of California, Santa Barbara, California 93106, USA
  • 7DIEF Department – University of Modena and Reggio Emilia, 41125 Modena, Italy

Keywords: underwater photogrammetry, underwater geodetic network, coral reef accretion, coral reef dissolution, camera evaluation, deformation analysis, accuracy evaluation

Abstract. Underwater photogrammetry is a well-established technique for measuring and modelling the subaquatic environment in fields ranging from archaeology to marine ecology. While for simple tasks the acquisition and processing of images have become straightforward, applications requiring relative accuracy better then 1:1000 are still considered challenging. This study focuses on the metric evaluation of different off-the-shelf camera systems for making high resolution and high accuracy measurements of coral reefs monitoring through time, where the variations to be measured are in the range of a few centimeters per year. High quality and low-cost systems (reflex and mirrorless vs action cameras, i.e. GoPro) with multiple lenses (prime and zoom), different fields of views (from fisheye to moderate wide angle), pressure housing materials and lens ports (dome and flat) are compared. Tests are repeated at different camera to object distances to investigate distance dependent induced errors and assess the accuracy of the photogrammetrically derived models. An extensive statistical analysis of the different systems is performed and comparisons against reference control point measured through a high precision underwater geodetic network are reported.