CAP tends to be less than specific about the areas covered, with regard to the VTEC-generated "weather wire" alerts. There are methods to get those in, as well. Some of us have been dealing with discrepancies in WEA and CAP for a long time and in the professional arena.
On Fri, Aug 4, 2017 at 10:11 AM, Dan Srebnick <k2...@k2dls.net> wrote: > I've developed a NWS CAP protocol parser to inject local weather events > into APRS. In doing so, I spent much time researching the required > format of such a message. > > I found detailed comments in alert.c. I also found a document from > WB4APR (http://www.aprs.org/APRS-docs/WX.TXT) that was updated in 2010. > There is documentation on http://www.aprs-is.net/wx/ that shows how > they format their Weather Alert packets and may represent the current > best practice. > > The three sources of info don't completely align. > > Comments in alert.c indicate that the "title" in received packets > should include an underscore between the state and the zone, i.e. > NJ_Z014. > > Packets generated via WE7U and AE5PL omit the underscore. That is what > Xastir actually seems to require, as it adds the underscore itself. If > the underscore is included, Xastir adds a 2nd and the display in the Wx > Alert window does not work properly. > > I am also trying to clarify whether the underscores between multiple > words in the "alert_tag" are required. Xastir comments state, "You > must ignore anything after a space in the alert." WB4APR says the > "type" is free text. Xastir doesn't actually seem to care and my > generated alerts look nicer without the underscores. But WE7U does use > it. > > Thought: Perhaps WE7U's data source includes underscores where the CAP > atom feed does not. I see that WE7U is one of the primary developers, > so please chime in. > > Nor does Xastir seem to care if there is a trailing comma (as specified > by WB4APR) after the last "title" element or a space between the last > "title" and the "{zcs" value. > > Perhaps the comments are out of sync with the current reality and could > be clarified by someone who fully understands the code as implemented? > This could be quite useful. > > The NWS CAP protocol (http://www.nws.noaa.gov/directives/sym/pd01017003 > curr.pdf) has defined the following "Significance" values: > > W - Warning > A - Watch > Y - Advisory > S - Statement > F - Forecast > O - Outlook > N - Synopsis > > Xastir already handles Warning, Watch, and Advisory. I would find it > useful, and therefore suggest/request, that the alert_entry.to > values be expanded to conform with the NWS CAP possibilities and to add > STMNT, 4CAST, OUTLK, and SYNOP to the list of values. > > Thanks for any comments and your consideration. > > 73, > > Dan K2DLS > _______________________________________________ > Xastir-dev mailing list > Xastir-dev@lists.xastir.org > http://xastir.org/mailman/listinfo/xastir-dev > -- Gerry Creager NSSL/CIMMS 405.325.6371 ++++++++++++++++++++++ “Big whorls have little whorls, That feed on their velocity; And little whorls have lesser whorls, And so on to viscosity.” Lewis Fry Richardson (1881-1953) _______________________________________________ Xastir-dev mailing list Xastir-dev@lists.xastir.org http://xastir.org/mailman/listinfo/xastir-dev
