Evaluation of multipath effects on depth measurements provided by acoustic transmitters in shallow water

• Takagi Junichi

  Graduate School of Informatics, Kyoto University

• Ichikawa Kotaro

  Field Science Education and Research Center, Kyoto University・CREST, Japan Science and Technology Agency

• Arai Nobuaki

  Field Science Education and Research Center, Kyoto University・CREST, Japan Science and Technology Agency

• Miyamoto Yoshinori

  CREST, Japan Science and Technology Agency・Tokyo University of Marine Science and Technology

• Uchida Keiichi

  CREST, Japan Science and Technology Agency・Tokyo University of Marine Science and Technology

• Fujioka Ko

  National Research Institute of Far Seas Fisheries, Fisheries Research and Education Agency

• Fukuda Hiromu

  National Research Institute of Far Seas Fisheries, Fisheries Research and Education Agency

• Mitamura Hiromichi

  Graduate School of Informatics, Kyoto University・National Research Institute of Far Seas Fisheries, Fisheries Research and Education Agency

Abstract

Measurement errors caused by multipath effects are one of the problems of acoustic biotelemetry, especially in shallow waters because both the sea surface and bottom can be major boundaries reflecting ultrasonic pulses. We conducted an experiment using transmitters with a pressure sensor to examine occurrence probabilities of multipath effects in a shallow sea area. We deployed seven transmitters with a 1.28-s signal transmitting interval in the same location, and two receivers located 18.5 m (R1) and 38.0 m (R2) horizontally from the transmitters. In order to solve the problems derived from multipath effects, we applied a state-space model to the depth data to estimate the correct values. Then we compared data availabilities, which were percentages of the number of correct values to the number of actual transmissions, between the acquired data and the model estimation. In 15 min recording, the mean proportions of the correct values for all transmitters were 88.4% for R1 and 86.3% for R2. The data availabilities became significantly larger from 65.7% to 96.7% with R1, and from 64.6% to 93.3% with R2 by applying the model. This suggests that we can reduce the measurement errors caused by multipath effects by post processing.

Journal

• PROCEEDINGS of the Design Symposium on Conservation of Ecosystem Volume 5 (The 16th SEASTAR2000 workshop)

  PROCEEDINGS of the Design Symposium on Conservation of Ecosystem Volume 5 (The 16th SEASTAR2000 workshop) 5 15-19, 2017-06

  Kyoto University Design School

Keywords

• biotelemetry
• ultrasonic coded transmitter
• multipath effect
• state-space model

Details

• CRID: 1390009224847165696
• NII Article ID: 120006654117
• DOI: 10.14989/226612
• HANDLE: 2433/226612
• Text Lang: en
• Data Source:
  • JaLC
  • IRDB
  • CiNii Articles
• Abstract License Flag: Allowed