Canadian weather radar network

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The Canadian weather radar network consist of 31 weather radars spanning across Canada's most populated regions. Their primary purpose is the early detection of precipitation, its motion and the threat it poses to life and property. Each has a range of 256 km in radius around the site to detect reflectivity, and a range of 128 km for detecting velocity patterns (Doppler effect).

Canadian weather radar network (Source: Environment Canada)

1 History
2 Characteristics
3 Scanning Strategy
4 List of radars
5 References
6 External links

[edit] History

Research in weather radars in Canada began at the end of the Second World War with "Project Stormy Weather"^[1]. After the war, J.S. Marshall continued at McGill University the work with the "Stormy Weather Group"^[2]. The Canadian network was thus gradually formed and by 1997, there were 19 weather radars of two kinds across the country: 18 five centimeter wavelength (C-Band) radars and 1 ten centimeter wavelength (S-Band) at McGill, all of the radars detected reflectivity with 3 sites equipped with Doppler capabilities (Carvel, King City and McGill).

Environment Canada received approval in 1998 to upgrade the network to Doppler standard and to add 12 more radars with the operational characteristics coming from King City Radar (CWKR), the research radar of EC. However, McGill radar (CWMN), while being part of the network, is owned by McGill University. It is a research as well as an operational radar and is modified independently.

[edit] Characteristics

McGill radar (CWMN):

9 meters (30 feet) diameter antenna.
Using a klystron to produce a wavelength signal of 10 cm.
Doppler since 1993 and dual polarization was added in 1999.

The rest of the network:

The upgraded radar have antennas from two manufacturers: Enterprise Electronics Corporation (EEC) and Raytheon.
The new radar have antennas produced by Andrew Canada. With a diameter almost double the old ones; resolutions improved by the same amount.
Use 5 cm wavelength emitting magnetrons.
Process received reflectivity and Doppler data with Sigmet Radar Data Systems.
Each radar in the network will thus be called an WSR-98E, WSR-98R or WSR-98A for Weather Surveillance Radar - 1998 (for the year of the start of the program) and the first letter of the manufacturer (Enterprise, Raytheon or Andrew).

[edit] Scanning Strategy

Because the network is using C band radars, compromises had to be used (see Doppler dilemna) between maximum reflectivity range and maximum non ambiguous velocities. The actual scanning strategy (2006) is divided in two separate scans over 10 minutes:

Conventional cycle: 24 elevation angles scanned in 5 minutes to obtain a tri-dimensional view of the atmosphere within 256 km of the radar in reflectivities.
Doppler cycle: 4 angles scanned in reflectivity and velocities, the first three in a range of 128 km and the last within 256 km. This cycle is used to locate possible small scale rotation and shear in the wind pattern as well as the large scale circulation. The velocity data help to filter artifacts in the reflectivity, like ground echos, too.

Only the McGill radar (CWMN) using its coherent S-band transmitter acquires reflectivities and velocities during each of its 24 elevation angles: 5 minute cycle time.

[edit] List of radars

The modernization process began in the fall of 1998 with the opening of Bethune radar and ended in 2004 with the one in Timmins ^[3].

**Canadian Weather Radar Network**
Site	Location	Province	ID	Band	Type
Aldergrove	Vancouver	British Columbia	CWUJ	C	98E
Bethune	Regina	Saskatchewan	CXBU	C	98A
Britt	Georgian Bay	Ontario	CWBI	C	98A
Carvel	Edmonton	Alberta	CWHK	C	98E
Chipman	Central New Brunswick	New-Brunswick	CWNC	C	98E
Dryden	Western Ontario	Ontario	CWDR	C	98E
Exeter	Southwestern Ontario	Ontario	CWSO	C	98A
Foxwarren	Eastern Saskatchawan/Western Manitoba	Manitoba	CWFW	C	98E
Franktown	Eastern Ontario	Ontario	CWFT	C	98A
Gore	Central Hants County	Nova Scotia	CWGO	C	98A
Holyrood	Eastern Newfoundland and Labrador	Newfoundland and Labrador	CWTP	C	98R
Jimmy Lake	NW Saskatchewan/NE Alberta	Saskatchewan	CWHN	C	98E
King City	Southern Ontario	Ontario	CWKR	C	98A
Lac Castor	Saguenay River	Quebec	CWMB	C	98E
Landrienne	Amos	Quebec	CWLA	C	98R
Marble Mountain	Western Newfoundland and Labrador	Newfoundland and Labrador	CWME	C	98A
Marion Bridge	Southeastern Cape Breton County	Nova-Scotia	CWMB	C	98E
McGill	Montreal	Quebec	CWMN	S
Montreal River Harbour	Sault Ste Marie	Ontario	CWGJ	C	98E
Mt. Sicker	Victoria	British Columbia	CWSI	C	98A
Mt. Silver Star	Vernon	British Columbia	CWSS	C	98A
Nipigon	Superior West	Ontario	CWNI	C	98E
Prince George	Northern B.C.	British Columbia	CWPG	C	98R
Radisson	Saskatoon	Saskatchewan	CWRA	C	98E
Schuler	Medicine Hat	Alberta	CWBU	C	98E
Spirit River	Grande Prairie	Alberta	CWWW	C	98E
Strathmore	Calgary	Alberta	CWSM	C	98A
Timmins	Northeastern Ontario	Ontario	CWTI	C	98E
Val d'Irène	Lower St. Lawrence	Quebec	CWAM	C	98A
Villeroy	Southwest of Quebec City	Quebec	CWVY	C	98R
Woodlands	Winnipeg	Manitoba	CWWL	C	98A