and now for the bad news: First, we do not have a "NEXRAD". "NEXRAD" is a nickname for the WSR-88D weather radars operated by NWS. Environment Canada (EC) runs a completely different weather radar system, with different processing. There are no direct equivalents to Level I, II, III, etc which originated in the early 1980's design of computers and telecommunications.
As I think I indictated this means we see fewer birds, even without any attempt to explicitly suppress them. They are simply detected less at the hardware level (roughly equivalent to Level I). We do see birds, but with much weaker returns than from NEXRAD (which is good from the weather perspective!). While we see them on some scans, on the publicly available images from EC weak echoes are suppressed to better match rain/no-rain as perceived by the public. Bird migrations are seen internally on displays showing all data to forecasters, and bird researchers with the Canadian Wildlife Service (part of EC) have used them in some studies. The CWS people have remarked on how much less we see birds relative to NWS radars, but are planning to expand their study. I believe the images used internally can also be purchased by external clients, but I am not involved with that. I don't think that imagery is archived, so a historical study would involve significant preprocessing costs. There has been some push to place these images on the public web site. There is also internal opposition to showing these images, because the interpretation of this data is much trickier and that results in public queries and complaints. In defence of the opponents, when our forecasters first got images that showed birds and insects they started harrassing the radar technical staff with complaints that the "radar was misfunctioning". We needed a significant training exercise.... Norman ____________________________________________________ David A. La Puma, Ph.D. Dept. of Ecology, Evolution, & Natural Resources Online Teaching Portfolio: http://www.woodcreeper.com/teaching Lockwood lab: http://rci.rutgers.edu/~jlockwoo Websites: http://www.woodcreeper.com http://badbirdz2.wordpress.com Photos: http://www.flickr.com/photos/woodcreeper On Fri, Sep 4, 2009 at 10:30 AM, David La Puma <woodcree...@gmail.com>wrote: > For those of you interested in the availability of Canadian radar, here are > the transcripts from my communication with Environment Canada: > * > My original inquiry:* > Hello, > I'm a researcher in New Jersey, USA, and I'm working with NEXRAD radar in > an attempt to quantify bird migration. Is Type II NEXRAD data available from > Canadian radar stations? Also, is there a website that serves up > non-filtered NEXRAD imagery, such that birds can be detected? > > *Their response:* > Thank you for sending your message to Environment Canada. I contacted our > radar expert and here's his reply regarding the tracking of bird migration > with our weather radars: > > "1) Much of the literature is based on American weather radar which use a > different technology from Canada. Our radars see birds less than the > American weather radars, which is good from the perspective of weather > application, but less good from a biologists point of view. > 2) The data is semi-quantitative, in the sense that we can say "a lot of > birds today", or "few birds today". We can try to say there are XXX birds > per hour migrating but there are large uncertainty in the estimates. > Nonetheless some biologist have seen interesting things in our weather > radar data, such as days when migrating birds completely over flew the > Toronto area (from NY to Muskoka) with few surface observations in GTA. The > biologists need to understand the advantages and limitations before > investing too much time. > > We could provide samples of bird migration images, but interpreting them is > not obvious to someone who does not have substantial training in radar. As > part of Environment Canada we are encouraged to promote extra uses for our > data, but we need to balance that against time taken away from our specific > jobs in meteorology." > > He also mentioned that you can contact him directly if you want more > information. His name is Norman Donaldson and his email is > norman.donald...@ec.gc.ca > > Best regards, > > Bernard Duguay > Meteorological Inquiry Specialist > MSC National Inquiry Response Team ISO 9001:2008 > Environment Canada > > > > *And my follow up question (still awaiting reply):* > > Norman > > Thank you so much for getting back to me regarding the radar. So as I > understand it, you are filtering non-weather data from your NEXRAD imagery, > in an attempt to only display weather-based returns on the reflectivity > imagery. I can absolutely understand the rationale behind that. Here in the > US the same process is done to varying degrees (depending on the outlet for > the imagery). It is my understanding, though, that the Level II NEXRAD > imagery is not filtered, and therefore represents the "raw" imagery which > can then be filtered and classified according to the needs of the > researcher. I have been using the commercially available radar imagery to > get an "idea" of bird migration over the Northeastern and Mid-Atlantic US to > use on my website (www.woodcreeper.com) where I make predictions about the > birding conditions following the migration flight each night during spring > and fall. In the future I am planning to use the Level II data to actually > extract density and velocity data in order to quantify bird migration for > specific locations. This work has been done before, and I plan to expand on > it for the region I am interested in. There have been several people working > on such projects locally, and a couple of them have expressed interest in > having more complete coverage to include the boreal forests extending into > Canada. > So, is it possible to get something equivalent to the Level II NEXRAD for > Canada? And also, could you provide some insight on what you filter out of > the data that is currently displayed at commercial outlets? > > Thanks so much for your help. > > Kind Regards, > > David > ____________________________________________________ > David A. La Puma, Ph.D. > Dept. of Ecology, Evolution, & Natural Resources > > Online Teaching Portfolio: > http://www.woodcreeper.com/teaching > > Lockwood lab: > http://rci.rutgers.edu/~jlockwoo <http://rci.rutgers.edu/%7Ejlockwoo> > > Websites: > http://www.woodcreeper.com > http://badbirdz2.wordpress.com > > Photos: > http://www.flickr.com/photos/woodcreeper > > > > > > > > On Wed, Sep 2, 2009 at 2:43 PM, Bryan Guarente <dafekt...@yahoo.com>wrote: > >> Jeff and others, >> Unless others know a source, I am unaware of anywhere that one can get >> unfiltered Canadian radar data. Unlike the US, Environment Canada/ >> Meteorological Service of Canada data is private. >> >> However, I am working with some Environment Canada people right now to see >> if there is a source available for this that I might be able to make >> available, or that is already available. >> >> I'll keep you posted. >> >> Bryan Guarente >> Instructional Designer >> The COMET Program >> University Corporation for Atmospheric Research >> Boulder, CO >> >> > -- NFC-L List Info: http://www.NortheastBirding.com/NFC_WELCOME http://www.NortheastBirding.com/NFC_RULES http://www.mail-archive.com/nfc-l@cornell.edu/maillist.html --
