Modern methods of transfer and usage of operative hydrological data
in vessels navigation systems
At present much of widely used navigation software employed on fishing boats has an built-in support
for viewing meteorological and hydrological information in GRIB format (files with extensions *.grib, ,*.grb, *.grb2, *.grb.bz2).
GRIB files (Gridded Binary) are binary files in specific format designed by the World Meteorological Organization (WMO)
for distributing data on weather conditions and oceanographic information. This file format is characterized by a high degree
of data compression and allows to transfer large amounts of information in a form of a relatively small original file which ideally fits wireless data transfer systems.
The table below presents a comparison of file sizes in various formats.
| Standard map of oceanological conditions in a graphic format (*.png), Kb |
90-100 |
| High resolution data for an area comparable to a graphic map,
in GRIB format (*.grb), Kb
|
20-40 |
| Packed data in GRIB format (*.grb.bz2), Kb |
10-20 |
A high degree of data compression can be achieved because GRIB file does
not contain any graphic information, but has only data on parameters confined to a coordinate grid
which enables the navigation system to view the GRIB file content in a form of a vector map layer, overlayed
on the navigation map. Multiple oceanographic parameters can be overlayed on navigation map for enhanced analysis. T
his also makes it possible to zoom to specific locations and view data in high detail.
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The use of operative hydrological information in the navigation
plotter environment can considerably facilitate the task of fish scouting and
catching for the fishing vessels and thus increase the efficiency of fishing operations.
Fish Scouting Department of AtlantNIRO is beginning work aimed at providing
fishing vessels with operative hydrological information, distributed in GRIB format.
The data is prepared at a regional level using techniques and software developed at the Department.
The data obtained on the basis of satellite information has high precision and spatial resolution. Operative data is prepared every 24 hours.
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Types of oceanological information provided in GRIB format:
- Data on sea temperature, sea surface temperature (SST);
- Data on ocean currents at the surface and at specific horizons (Current);
- Altimetry data (altimetry, SSH deviation);
- Data on ice conditions (Ice cover);
- Data on phytoplankton (Chlorophyll A).*
Note
- viewing oceanological parameters contained in the GRIB file is possible only if the parameters are supported by the user navigation system.
*- identification of this particular parameter is not included in the GRIB file and in order to visualize the information, substitution of identification code is required.
It is worth noting that some manufacturers of navigation systems also offer to receive data on
oceanological conditions from their services but their data is formed
on the basis of commonly used models for the entire ocean and have low resolution and indefinite precision.
Advantages of operative hydrological information in GRIB format:
- decrease in costs for receiving information;
- viewing data in the navigational plotter environment;
- making the mode of data viewing adjustable to the convenience of the user;*
- layer multiple oceanographic parameters on navigation map for enhanced analysis;
- zoom to specific locations and view data in high detail;
- taking readings of the parameters immediately below the cursor (latitude, longitude and oceanological parameters at that point).
Note
* - possibility and modes of adjustments for viewing oceanological parameters contained in the GRIB file depend on whether these adjustments are supported by the features of the user navigation system.
Download demo GRIB files with oceanographic parameters for CEA area:
If You dont have navigation system with GRIB files support, You can use specialized software for viewing GRIB files.
We recommend to use free GRIB viewer Expedition LT from
Tasman Bay Navigation Systems. You can download it from our web site.
SST Maps
Sea Currents Maps
Sea Ice Maps
Special Maps
