Shipborne C-band Dual-Polarization Weather Radar
The shipborne C-band dual-polarization weather radar is oriented toward the ship's bow, with an observation range of approximately 90 degrees on each side in azimuth, elevation from 0 to 90 degrees, and a distance of up to 150 km. The temporal resolution of observations is 6–10 minutes, with a spatial resolution of up to 100 meters. The radar is designed to work with a gyroscopic stabilization system to correct for motion caused by ocean waves, and uses GPS signals to compensate for the ship's movement, thereby providing high-quality maritime radar observation data. Observed variables include: reflectivity, radial wind field, spectrum width, differential phase, differential reflectivity, and correlation coefficient. The dual-polarization radar leverages multiple observed variables to enhance data quality, providing more accurate offshore precipitation observations. By combining radial wind field data with 3D wind field algorithms, it is possible to resolve the wind field and the three-dimensional structure of clouds and precipitation within marine convective systems.
Using differential reflectivity to infer precipitation drop size distribution allows for accurate estimation of rainfall intensity and spatial distribution over a large area (~20,000 km²). Observing the characteristics of different rain types through differential phase, differential reflectivity, and correlation coefficient allows the identification of precipitation particle types in three dimensions (including drizzle, moderate rain, heavy rain, ice crystals, snow, hail, and mixed-phase hydrometeors). Utilizing the R/V New Ocean Researcher 1, radar observation coverage can be extended from land to surrounding seas and open oceans near Taiwan, collecting 3D wind fields and cloud microphysics of various oceanic precipitation systems. This enables analysis of how the marine atmospheric boundary layer affects oceanic rainfall, helping to understand the coupling and feedback mechanisms between the atmosphere and ocean, as well as the interaction between weather systems near Taiwan and topography. By integrating 3D wind and cloud microphysical properties of potential convective clusters with satellite data and data assimilation techniques, better initial conditions can be provided for coupled atmosphere-ocean numerical forecast models, enhancing typhoon forecast accuracy.
Collecting characteristic data of various oceanic precipitation systems contributes to validating global coupled atmosphere-ocean climate models, addressing the historical lack of atmospheric data over oceans, and improving model accuracy in the Western Pacific. Integrating with Taiwan’s space program, the radar observations support the development of a validation platform for atmospheric parameters in the Western Pacific, improving the accuracy of products derived from indigenous satellite data. Accurate estimation of rainfall over large areas using weather radar, combined with sea salt observations, facilitates studies on the mixing mechanism between precipitation and ocean surface salinity, improving the treatment of mixing processes in oceanic numerical models.
Application Plan of the Shipborne Weather Radar on the R/V New Ocean Researcher 1
1. Analyze the dynamics, cloud microphysics, rainfall processes, and boundary layer variations of convective systems over the ocean.
2. Study the impact of BSISO (Boreal Summer Intraseasonal Oscillation) on rainfall and ocean response in the South China Sea and Northwestern Pacific.
3. Understand atmospheric and oceanic environmental features prior to the formation of typhoons, mei-yu fronts, and the southwest monsoon to improve forecasting.
4. Investigate ocean-atmosphere interactions and their influence on severe weather formation.
5. Explore feedback effects of different precipitation systems on the ocean, such as changes in salinity caused by rainfall.
6. Validate data from other instruments, such as satellites and buoys.
7. Study atmospheric conditions under varying conditions of the ocean diurnal warm layer (DWL).
8. Analyze feedback mechanisms between winter northeast monsoons and the ocean in the East China Sea and northern Taiwan waters.
9. Participate in or support future international collaborative atmospheric and oceanic research (e.g., TEPEX).
10. Extend the observation range of land-based weather radars to the ocean.
11. Assist in offshore wind farm assessments.
Past Conference Discussions
Dec 13, 2019: MOST Precious Instrument (New Ocean Research Vessel) Long-Term Development Advisory Meeting
Jan 9, 2020: MOST Precious Instrument (New Ocean Research Vessel) White Paper Discussion Meeting
Apr 1, 2020: Atmospheric Division – Joint Observation Platform Planning Meeting for New Ocean Research Vessel
Jul 7, 2020: MOST Joint Atmospheric and Oceanic Observation Topics Discussion Meeting
Jul 9, 2020: CSIST Shipborne Radar Experience Exchange Meeting
Jul 30, 2020: Atmospheric Division Researchers Visit R/V New Ocean Researcher 1 (Keelung Shipyard)
Sep 24, 2020: MOST Marine Technology Forward-looking Research Master Plan Meeting
Oct 20, 2020: China Corporation Register of Shipping Headquarters in Taipei (Discussion on Feasibility and Regulations)
Oct 21, 2020: MOST Marine Technology Forward-looking Research Master Plan Second Meeting
Oct 29, 2020: Atmospheric Division Business Briefing
Nov 25, 2020: Meeting on Installation of Shipborne Radar on R/V New Ocean Researcher 1 (Kaohsiung Office, discussion on construction details)
Mar 18, 2021: First Negotiation Meeting on Installation of Weather Radar on R/V New Ocean Researcher 1 by MOST
Apr 15, 2021: Second Negotiation Meeting on Installation of Weather Radar on R/V New Ocean Researcher 1 by MOST
May 3, 2021: Meeting with Director Cheng Ming-Tien of CWB to discuss future cooperation
May 12, 2021: Working Group Meeting for Shipborne Weather Radar Installation on R/V New Ocean Researcher 1
Discussion Highlights
1. Is there enough space on the R/V New Ocean Researcher 1 to install the weather radar?
2. What type of weather radar can be installed?
3. How will the installation be conducted (regulations, technology, ship modification, etc.)?
International Shipborne Radar Expert Exchange
Australia - Investigator: Dr. Alain Protat, BOM [Data Acquired]
Nov 21, 2023, NCU Atmospheric Department:
Statistic properties of tropic convection to inform cumulus parameterization.
Nov 22, 2023, NTU Institute of Oceanography:
Multidisciplinary science enabled by the Australian Research Vessel Investigator.
Japan - Mirai (RV Mirai): Dr. Katsumata, JAMSTEC [Technical Documents Acquired]
USA - CSU SEA-POL: Dr. Michael Bell, CSU [Technical Documents from 2018/2019]
All exchanges have been completed.
Building shipborne meteorological radar alliance.
May 15, 2023 – First manufacturer delay notice due to COVID-19 affecting factory inspection and shipment: postponed to Feb 2024
Oct 27, 2023 – Second delay notice: postponed to Aug 2024 [High Voltage Pulse Modulator]
Dec 20, 2023 – Third delay notice: postponed to Nov 2024 [Inertia Motion Control Unit (IMU)]
Feb 15, 2024 – Apr 20, 2025: 10 online meetings for progress discussions
Original completion date: Jun 13, 2025. Manufacturer requests extension to Jun 12, 2026
EEC Estimated Receipt of Material - November 2025
EEC Software Embedded Development - November–December 2025
Official Notification to GECL/NTU for FAT Ready - December 2025
Startup, Calibration and Endurance Testing - January 2026
Factory Acceptance Test - March 9–13, 2026
Freight Arrival in Taiwan - April 30, 2026
Installation - May 2026
Site Testing - May 25–29, 2026
Conclusion on Shipborne Weather Radar Instrument
The manufacturer has caused significant delays in radar progress. Progress continues to be monitored, aiming for installation and testing between Q4 2025 and Q1 2026.
Analysis software has been established and foreign radar data acquired for verification and testing.
Integrated atmospheric division instrumentation completed NORI-0069 and NORI-0075 cruises, testing instrument operation on R/V New Ocean Researcher 1. Participating institutions: NCU, NTU, Taipei University, Academia Sinica.
Domestic atmospheric observation teams are now regularly participating in R/V New Ocean Researcher 1 cruises.
Enhanced observations of marine atmospheric boundary layer and precipitation.
Expanded collaboration between atmospheric and oceanic research teams.
Ongoing contact with ship radar research teams from Japan, Australia, and the U.S. to establish collaboration.