The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
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Articles | Volume XLIV-M-2-2020
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLIV-M-2-2020, 15–24, 2020
https://doi.org/10.5194/isprs-archives-XLIV-M-2-2020-15-2020
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLIV-M-2-2020, 15–24, 2020
https://doi.org/10.5194/isprs-archives-XLIV-M-2-2020-15-2020

  17 Nov 2020

17 Nov 2020

ASSESSMENT OF THE PRECISION OF A SMART-PHONE POLE PHOTOGRAMMETRY FOR A SECOND-ORDER CLIFF SURFACE DEFORMATION STUDIES

M. A. Eboigbe and D. B. Kidner M. A. Eboigbe and D. B. Kidner
  • University of South Wales, Faculty of Engineering and Computing, UK

Keywords: Pole Photogrammetry, Coastal Cliff, Deformation Study

Abstract. Coastal cliff is almost a vertical elongated structure with a wave-cut notch and a landslip. Cliffs are geological formations with an almost unpredictable and unstoppable detachment between constitutes formations. Due to health, safety, environmental, and military restrictions, there are more regulations and restrictions on the use of drones. There are also the issues of portability and high cost for the purchase of hybrid drones and Terrestrial Laser Scanners (TLS). These negate the regular monitoring of the coastal cliff. This research develops a rapid, low-cost, and precise digital photogrammetry methodology for the continuous monitoring of the cliff by using the pole as the platform and a mobile phone as a sensor. The most practical vertical camera angle, image overlaps, survey distance to the cliff, and realistic time range for surveys are all determined from the basic surveying principles. Precise geometrically related point clouds generated are with or without the Global Navigation Satellite Systems (GNSS). The standard deviation for “alignment and surface deviation” at every point on each point cloud is ± 0.05 m in the Northing and ± 0.12 m on the Easting’s for the self-calibrated digital camera and without the use of GNSS control points. With the GNSS controls, the maximum deviation in the XYZ coordinates is ± 5 cm. Change analysis performed identifies areas of cut, fill, and the segment of threats in all point clouds. The photogrammetric technique developed is very cheap, simple, and reliable with minimum labor. The results obtained indicate the applicability of this methodology for second-order cliff Deformation study.