NHREAS

"A Very High Resolution Weather, Wave and Ship Safety Forecasting System"
G. Kallos¹, E. Mavromatidis¹, G.Galanis¹, F. Gofa¹, A. Laskaratos¹, G. Korres¹, G. Tompras¹, G. Souvatzoglou⁷, C. Sarlanis⁷, C. Efstathiou¹, K. Politis², J. Vergados³, G. Sakelaridis⁴, E. Markou⁴, C.Tremback⁵ and J. Snook⁶

1 University of Athens, School of Physics, Division of Applied Physics
2 Hellenic Ship Registry-HSR, Piraeus, Greece
3 Innovative Technology Center –ITC S.A., Athens, Greece
4 Hellenic National Meteorological Service, Athens-HNMS, Greece
5 ATMET S.A., Boulder, CO, USA
6 CORA S. A., Boulder, CO, USA
7 ISNET, Athens, Greece

Project: New EKBAN 1.3-87
Ministry of Development – General Secretariat for Research and Technology

Project started in 1998 and ended in 2000.

More specific and we designed and implemented a mobile meteorological station that measure and trasmiting parameters through GSM/GPRS, INMARSAT B and Satelite Internet data to Hellenic National meteorological Service.
We implemented the part of server in the Hellenic National meteorological Service too.

Coordinator: University of Athens, School of Physics, Atmospheric Modeling and Weather Forecasting Group, Assoc. Professor G. Kallos

Other Partners:
School of Physics, Oceanography Group, University of Athens
School of Physics, Telecommunications Group University of Athens
School of Informatics, University of Athens
Hellenic National Meteorological Service (HNMS)
Hellenic Ship Registry (HSR S.A.)
Strintzis Lines S.A.
Innovative Technology Center (ITC S.A.)
ISNet

SCOPE OF THE PROJECT

THE DEVELOPMENT of: A very high resolution forecasting system for weather, waves and ship safety to support the coastal transportation system between the Greek Mainland and the Aegean Islands.

The system consists of:

• A high resolution atmospheric module (RAMS and LAPS).
• A high resolution wave module (WAM), for Greek Seas and mainly for Saronic Gulf and Central Aegean.
• A telecommunication module which employs advanced data transferred systems (GSM, DCS1800, INMARSAT etc. connections)
• A data gathering and distribution module (with two parts one at HNMS and the other on board of the ships).
• A ship stability and safety module on specific weather and sea conditions (SWAN module).

Operational use of NHREAS system:

• Retrieval of ECMWF meteorological and SST fields for initial and boundary conditions.
• Retrieval of all available surface observational data from surface and ship stations (NHREAS stations).
• Retrieval of all available upper-air data.
• The Data Assimilation System LAPS is used to prepare initial conditions based on the ECMWF gridded fields as initial guess, the surface and upper-air observations available at the HNMS and the data gathering from the telecommunication system of NHREAS.

The system produces:

• 36-hour forecasts starting at 00:00 UTC.
• Post-processing and preparation of graphical representations of RAMS results.
• Usage of model results as input at the 4th generation wave model WAM for wave forecasting.
• Post-processing and preparation of graphical representations of WAM results.
• Update of the system’s server and web page for interactive usage.

Users (e.g. the crew of the ship):

• Can browse at NHREAS server located at HNMS for weather and wave forecasts and at the same time they can gather the necessary data for scenario development about the safety and route to follow.
• Telecommunication is realized through three alternative ways: GSM data service, INMARSAT class-B data transfer and satellite internet.
• The data gathering system of HNMS downloads the data from each ship-station every 15? automatically through the telecommunications systems available at each ship.
• The ship-stations download the data to HNMS through INMARSAT and satellite internet connections.
• Each ship-station has extra sub modules like GPS and electronic compass for positioning and true wind calculations.
• Conventional RAMS outputs are also available at HNMS.

The final users for the pilot implementation of the project were chosen to be the following ships:

• BLUE STAR FERRIES «SUPER FERRY II»
• BLUE STAR FERRIES «ITHAKI»
• MINOAN LINES «KNOSSOS PALACE»

COMPUTER RESOURCES
The computational system, which is in use at HNMS for NHREAS consists of:

• A cluster of 3 dual-CPU HP/J6000 + 1 single CPU HP/C-3000 (as Control Workstation) linked with 1GBit Switch (optical).
• An HP/server (1GHz PENTIUM) with dial-up modems.
• All the systems are linked with the other subsystems at HNMS through a 100 Mbit net .
• The connection with the internet is made via the University of Athens and ECMWF.

SHIP TERMINAL STATION
The terminal station at the ships consist of two basic operational parts:

• The sensors for the meteorological and positioning data.
• The computer that supports: a) Two-way communications with the main server at HNMS. b) Gathering, retrieval and storage of the meteorological data and the position of the ship. c) Retrieval of weather and wave forecasted fields. d) Performance of ship stability calculations for safer and optimum navigation according to wave conditions, cruising speed and route to follow.

The meteorological mast on the "Bluestar Ithaki" deck.

We can see the anemometer, the GPS antenna, the temperature and humidity sensors, the wind sensors, the gsm antenna and the compass. The installation takes into account the sea environment in order to resist to near sea conditions and the acceleration conditions that items meet during the ship movement under different sea conditions.

THE COMPUTER SYSTEM AT THE SHIP DECK

The prototype system at “Blue Star Ithaki”. In each of three Ships installed different systems with different type of instruments and ways of communications in order to evaluate the best performance. In the later versions of the system the computer boards and the other electronics are within a box with fixed specifications and the control of the system is made through a touch-screen and track-ball system.

The computer system

The computer system has the role of

• Display the current meteorological conditions around the ship.
• Storage the data that ship datalogger gather.
• Sending gathered data every 10 minutes (1 minute measurements) to the Hellenic Meteorological Service. Later in the project datalogger has the same capability and the one system worked as backup of the other.
• Get data and images with forecasting charts from the prediction models and display on the ship monitor

Marine type wind –gauge and wind-vane
In the picture we can see the model 05106 marine type anemometer of RM Young Company. In the project we evaluate some types of anemometers. Between them were ultrasonic and cup anemometers and wind vanes.

Compass Sensor
In the picture we can see the Flux Gate compass sensor DH0200 of Ritchie. We use some type of similar sensors from different suppliers. The use of a such sensor was critical especially when ship was not make moves of make movements inside a harbor. In such cases the GPS sensor is useless in order to continue to have valid wind data.

GPS Sensor
You can see the marine type GPS by Koden company. We use a number of sensors in the project independent or combined with a GSM modem.

Signal Conditioning Unit
We can see the signal conditioning unit. It can handle the following sensors

• A PT-100 thermometer
• A voltage output Humidity sensor
• A voltage output Barometric pressure sensor
• A RS-232 NMEA0183 output compass sensor
• A RS-232 NMEA0183 output gps sensor
• A RS-232 NMEA0183 output wind sensor
• A Voltage output wind sensor (2 inputs)
• A pulse output cup anemometer
• A RS-232 gsm modem

It sends its output to the Ship Computers and communicate with it in order to handle a number of situations.

RESULTS AVAILABLE AT THE NHREAS WEB SERVER (Prognosis)

Wind speed and direction
Wave direction and significant height
Wave direction and period
Temperature at 2m
Cloud coverage (percentage)
Accumulated precipitation (last 3 hours)
Wind and Wave fields for interactive retrieval from ships for the ship-safety calculations and optimal route path. These data are available for the highest resolution available of the selected location.