An advanced weather radar network for the Baltic Sea Region: BALTRAD

International weather radar networking is a topic that has been addressed in Europe in different ways throughout the last few decades: in COST actions, EUMETNET, and through regional networks. International networking is a prerequisite for achieving the greatest cost-effectiveness in radar hardware investments in Europe, with its great diversity of countries, physical environments, and hazardous weather conditions. Despite this, however, exchange of radar data is still largely performed bilaterally using primitive mechanisms. Real radar networking is uncommon and mostly limited to domestic solutions. The prototype European composite at EUMETNET OPERA's Pilot Data Hub is a welcome step towards a true European weather radar network, yet much work remains before this goal is achieved. The BALTRAD project was officially underway on 1 February 2009, and it will continue until 31 January 2012. The source of funding is the European Union's regional programme INTERREG IV B, the Baltic Sea Region (BSR). The project's budget is 2.1 M€, and the allocated amount of work, expressed in full-time equivalent, is around 27 years. In addition, we have significant resources as external services, travel, and investments in the form of computer servers.
The objective of BALTRAD is to create an advanced weather radar network for the BSR, as a durable and sustainable element of regional infrastructure.
The Partnership comprises the following government organizations:
Swedish Meteorological and Hydrological Institute (SMHI, Lead Partner)
Finnish Meteorological Institute (FMI)
Institute of Meteorology and Water Management (IMGW), Poland
Latvian Environment, Geology and Meteorology Agency (LEGMA)
Danish Meteorological Institute (DMI)
Republican Hydrometeorological Center (RHMC), Belarus
Radiation and Nuclear Safety Authority (STUK), Finland
Estonian Meteorological and Hydrological Institute (EMHI)
We have also associated organizations in Denmark (Ålborg University), Latvia (LGS, the aeronavigation service provider), and Poland (Silesian Voivodship Office) who will be contributing in various ways.
BALTRAD represents the first dedicated international weather radar networking project funded by the European Union However, the concept we're following has already been proven once before, with the establishment of the NORDRAD network involving the radars from Norway, Finland and Sweden, around 20 years ago. The original NORDRAD technology has become outdated and it is time to follow a new paradigm. In doing so, we hope to create the following:

• exchange of polar data among all members of the Partnership
• a weather radar data exchange framework fully compliant and preferably integrated with the WMO Information System (WIS)
• a common production framework containing harmonized algorithms, including those employing dual-polarization data
• consistent end-to-end management of quality information
• a software system which is available according to Open Source principles.The goal is to achieve cutting-edge distributed radar networking, ie. a network where data is exchanged on equal terms and where each institute processes the data according to its local needs. In achieving this, we hope to establish a community-based critical mass which will be sustained and enlarged after the completion of the project.

The project is organized into the following work packages, which are limited to a maximum of seven by the BSR.

1. Management and Administration. This is a mandatory work package run by SMHI.
2. Communications. This is also a mandatory work package dedicated to both internal and external communications. It is the responsibility of FMI.
3. Core network. This work, led by IMGW, is dedicated to creating the real-time networking functionality. We foresee that it will be based on secure HTTP-based mechanisms with subscription services. Our long-term goal is that we contribute such mechanisms to WIS for Europe.
4. Data catalogue. This work involves managing all data to be exchanged and processed. EMHI leads this work which will focus on creating a database for all metadata and systematic methods for storing data files.
5. Production framework. FMI leads this work, which deals with developing, collecting, and harmonizing numerous algorithms for improving the quality of data and creating products from them such as composites directly from polar volume data. Products based on dual-polarization moments will be included in this work, as several of the operational radars in the region are dual-pol, and more are on the way. The production framework itself will likely be RPC-based, where algorithms may be implemented using any of the C/C++, Java, and Python programming languages.
6. Deployment. This involves integrating the outputs of work packages 3-5 into a real-time system suitable for operational deployment. SMHI leads this task. Regular releases will be installed at all Partners, and they will be evaluated within the project using dedicated teams in e.g. LEGMA and the RHMC.
7. Pilots. This work, led by IMGW, serves to make the BALTRAD system and its radar-based information available to test pilots, to collect the pilots' feedback to integrate new and improved software and products. A case log will be prepared containing cases relevant to air traffic, flash flooding, urban hydrology, and radiation accident scenarios. In this way we will demonstrate the value achieved in a true end-to-end radar network.

However, we should clarify that there are no resources in BALTRAD for procuring new radars. Notwithstanding this constraint, BALTRAD will create software converters which will harmonize all polar data from all radars in the network to a common format: HDF5 following the official European standard defined in OPERA.
BALTRAD software will be available for free according to EU regulations. Some form of Open Source license that protects intellectual property rights will be applied; one candidate currently being considered is the Lesser Gnu General Public License.
In summary, BALTRAD will deliver freely-available, community-developed software which we hope will spread "organically" throughout Europe, enabling the advanced networking of weather radar data in a harmonized way. A harmonized set of production algorithms will also be included, and we encourage the community to contribute their algorithms too. An important outcome is the ability to provide end users with high-quality radar-based information which will facilitate their daily decision-making activities.