The National Radar Program

Frequently Asked Questions

Implementation of the National Radar Project

Why do we need a Doppler weather radar network?

Experience in the United States and Canada has shown that Doppler weather radar can be a very useful tool in improving the prediction of severe weather events.

Meteorologist using Doppler weather radar along with other state-of-the-art tools and techniques will be able to:

1. Identify and more precisely define the areas where severe weather is likely to occur;
2. during summer severe weather events, search for characteristic patterns indicating a high probability of severe thunderstorms, hail and tornadoes;
3. forecast the timing, intensity and location of heavy precipitation events with greater precision.

The goal is to be able to provide sufficient warning to the public to ensure their safety and security and to assist in the implemention of emergency planning with a view to minimizing damage and economic loss.

How was the area of coverage for the Doppler weather radar network determined?

The area of coverage of the Doppler weather radar network across Canada was determined principally by using criteria reflecting the probability of occurrence of severe weather (thunderstorms and tornadoes, heavy rainfall, heavy snowfall, freezing precipitation etc.,) and population density. The network which was created provides virtually continuous coverage over the populated areas of the country most susceptible to severe weather.

How were the specific sites chosen in the network? What were the criteria?

A number of factors were considered in determining specific site locations, notably the location of radars in the the conventional network at that time, the effective area of coverage of a Doppler radar, and the location of U.S. National Weather Service radars adjacent to the Canadian borders. MSC's weather radars have an effective circular coverage area that is approximately 256 km in diameter when operating in Doppler mode, and 512 km diameter in conventional mode.

Some of the existing radars were upgraded on site. New sites were chosen to fill major gaps in the coverage. In some cases, radars which formed part of the conventional network were upgraded and moved to to a different location to ensure complete coverage The plan assumed that MSC would have access to the U.S. National Weather Service radars which provide partial coverage along the border with Canada .

  Each new radar site required detailed investigation. Selection factors include local terrain type, site elevation and obstructions, availability of telecommunications, access to property, and other factors. An environmental assessment was conducted for each new site prior to site preparation.

How was the order and timing of the Doppler weather radar installations determined?

  The princiapal factors which had an influence on the installation timeline were the same as were used to determine the siting of the network, the likelihood of severe weather and population density, the gaps in the existing conventional network and the logistics of implementation.

  The highest priority was to fill gaps in the current network where there were significant risks of severe weather. The order of implementation of the remaining sites followed the general criteria to the extent permitted by the logistics of implementation. The plan was to maintain continuous radar coverage at existing sites during the installation of the Doppler radar. To do this, equipment from other locations was installed at that site. Once the new equipment was made operational, parts of the old radar were moved and upgraded for another site.

How long did it take to install a Doppler weather radar and why six years to complete the Project?

  It took 18 months to install and commission the first two Doppler weather radars. This included all of the preparatory work to purchase the Doppler components, the establishment of contracts, the selection and environmental assessment of sites, site preparation and the installation and commissioning of the radars. The schedule for completion of the Project was dependent on year-by-year allocations of funding and was also affected by changes in scope.

For subsequent radars, the amount of time to install and commission varied. At existing sites, assuming all the hardware was available, it took on average three months to complete site preparations, assemble the hardware, install and commission the radar. At new sites much more work was involved with the selection and preparation of sites. Consequently, at these sites, installation and commissioning took somewhat longer.

Why 31 Doppler weather radars? Why not 25 or 45?

MSC's weather radars have an effective Doppler coverage area that is approximately 256 km in diameter. In conventional mode, the coverage is 512 km in diameter. The radar network was conceived to provide complete coverage over populated areas with significant potential for severe weather at the minimum possible cost. 30 MSC radars, combined with the 2 DND radars and the system at McGill provide this coverage provided there is access to the U.S. radar network along the Canadian borders.

Who were the suppliers of the radars and other equipment required for the project?

The Meteorological Service of Canada (MSC) contracted with several companies for the supply of major modules used for the radar systems, but retained the responsibility for system design, integration and installation. This enabled MSC to implement state-of-the-art high performance weather radars and processing systems which are extremely cost-effective. Other national meteorological services have expressed considerable interest in the characteristics of our radar systems and the technologies we have used. By retaining control of the design and maintaining the related technical expertise, MSC is in an excellent position to further develop the capabilities of its radar systems over the years to come. Companies holding major contracts to supply modules include: Andrew Canada (antenna systems), Canadian Space Services (supply and installation of radomes), and SIGMET Inc. (signal processors, radar control processors and data acquisition software).

How will the Canadian and U.S. networks work together?

 Since weather knows no political boundaries, it is important that potentially life-threatening meteorological information be shared internationally. Canada and the United States  have signed an agreement to share the information derived from their respective radar networks so that a continuous flow of information exists across the border.

Will Doppler weather radar be available to television stations?

Doppler radar is primarily a tool for the meteorologist to prepare warnings and public forecast products. Media and the public will benefit through the quality of warnings and forecasts. However, television stations may be interested in broadcasting Doppler images as part of their weather segment. These data can be incorporated as part of any service agreement the stations may have with Environment Canada. The direct use of Doppler radar imagery and data by others is considered to be a specialized service and is therefore subject to a fee to recover costs.  Some stations have their own Doppler weather radar.

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