Research on dense observing network of precipitable water by using on-vehicle low-cost GNSS receiver systems

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K21847
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 63:Environmental analyses and evaluation and related fields
• Research Institution: Yamaguchi University
• Principal Investigator: Imaoka Keiji 山口大学, 大学研究推進機構, 准教授 (50725869)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: GNSS / 水蒸気 / 可降水量 / 低コスト / 移動体

Outline of Final Research Achievements

Observations of water vapor with high temporal frequency and high area density are desired for many purposes including early detection of severe rainstorms. To reduce the cost for installation, utilizing low-cost GNSS receivers is highly expected. In this research, for the purpose of establishing dense water vapor observation network by using on-vehicle low-cost GNSS receivers, we constructed the observing system with two-frequency low-cost GNSS receiver and evaluated the estimation performance of water vapor by comparing with geodetic-grade GNSS receiver system and radiosonde observations. As a result, low-cost GNSS receiver system exhibited comparable performance with that by geodetic-grade system in estimating water vapor. Although we were not able to show reasonable performance for on-vehicle experiment, at least low-cost GNSS receivers are promising in constructing denser observing network of water vapor with fixed stations.

Free Research Field

宇宙地球計測学・人工衛星リモートセンシング

Academic Significance and Societal Importance of the Research Achievements

平成30年7月豪雨における線状降水帯に伴う大雨や大型台風の上陸頻度増加など，地球温暖化の影響と考えられる極端な気象現象の頻発が近年問題となっている．このような風水害に備えるためにはその兆候をいち早く把握し，対応のリードタイムを確保することが重要である．本研究成果は，降水に先行する水蒸気の挙動の高頻度・高密度な観測網の構築に資するもので，防災の観点から社会的意義を有する．また，近年市場に展開されている低コストGNSS受信機による水蒸気観測の精度を，ラジオゾンデ観測との長期比較により初めて直接的に検証した点に学術的意義がある．