Comparative Analysis on Interpolation Methods for Bathymetric Data Gaps

  • Joseph E. Acosta University of the Philippines Mindanao
  • Vicente B. Calag University of the Philippines Mindanao
  • Zarah Jean I. Diche University of the Philippines Mindanao
  • Christine Lou A. Lazaga University of the Philippines Mindanao
  • Trisha Mae N. Lopena University of the Philippines Mindanao
  • Daisuke A. Tatsuda University of the Philippines Mindanao

Abstract

Light Detection and Ranging (LIDAR) technology delivers high accuracy elevation values and ground features. However, the capability of this technology is inhibited in terms of its strength to penetrate certain surfaces. For instance, LIDAR is limited to the elevation values of the river water surface and not the elevation of its riverbed. Hence, topographic and bathymetric surveys are conducted to obtain an accurate set of elevation values for areas where the technology is unable to permeate. Bathymetric surveys are conducted using a scientific echo sounder equipment, which utilizes sonar technology to determine the river depth relative to the water’s surface by transmitting sound pulses and calculating the interval between the emanation and regress of a pulse per unit time. Like in all remote sensing measurements, errors are inevitable. Noise and external factors that cause faulty or bad readings result in data gaps. Gaps in the gathered elevation data sets can only be identified during filtering, which is done after the actual survey. In addition, covering the gaps back in the field would mean additional costs. This study aims to maximize data gathered by using different interpolation methods to generate points in the data gaps. Inverse Distance Weighting (IDW), Spline, and Kriging methods are used to extrapolate the values within the gaps. These values are then used together with the rest of the data for bathymetric data integration into the LIDAR data using IDW. Statistical calculations are shown to analyze the accuracy and efficiency of the results.

Keywords: bathymetry · interpolation · remote sensing limitations

Published
2021-12-31
Section
Research Articles