• Journal of Space Technology and Applications
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• v.4 no.3
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• pp.199-209
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• 2024

In this study, we calculated total electron content (TEC) using ship-borne global navigation satellite system (GNSS) observations and validated the results by comparing the ground-based TEC. GNSS is an effective tool for monitoring the ionosphere as it allows 24-hour observations, is low cost, and is easy to install. However, most GNSS stations are located on land, which leads to a lack of data from the ocean. Therefore, we conducted an experiment collecting GNSS data in the ocean by installing GNSS observation systems aboard the research vessel 'ISABU', operated by the Korea Institute of Ocean Science and Technology. We estimated TEC using GNSS data from July 30 to August 24, 2021. From the results, we confirmed daily and latitudinal variations of TEC as expected. Additionally, we compared the results with TEC derived from nearby ground-based GNSS stations and then verified similar variations. Based on these results, we plan to research ionospheric climatology using long-term data and assess its potential for ongoing ionospheric monitoring.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.783-790
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• 2010

For safety navigation of ships at sea, ships monitor their location obtained from Global Positioning Satellite System (GNSS). In this study, we computed near-real-time positions of a ship at sea using GPS Precise Point Positioning (PPP) technique and analyzed precision of the near-real-time positions. We conducted ship borne GPS observations in the south sea of Korea. To process the GPS data using PPP technique, GIPSY-OASIS (GPS Inferred Positioning System-Orbit Analysis and Simulation Software) developed by the Jet Propulsion Laboratory was used. Antenna phase center variations, ocean tidal loading displacements, and azimuthal gradients of the atmosphere were corrected or estimated as standard procedures of high-precision GIPSY-OASIS data processing. As a result, the precisions of near-real-time positions was ~1cm.