[EAS] IPAWS and NOAA

[Dave Turnmire]

I recently received an email that clarified for me some of the issues 
regarding IPAWS and NOAA Weather.  One of those concerns why NOAA 
Weather is able to send CAP alerts via the Public and WEA channels of 
IPAWS, but not the EAS channel.  As I understand it, the issue is that 
the CAP version will list all the relevant counties for that alert.  
But... a given NWR transmitter will only include the counties within its 
coverage area.

So... in some situations, the version a broadcaster receives from NWR 
will be identical to the version the broadcaster might receive from 
IPAWS... except the NWR version may leave out one or more counties 
included in the CAP version.  It sounded like an additional issue was 
that in addition to the list of counties not being identical, that the 
list may also be in a different sequence. Which... means the EAS decoder 
won't consider them duplicates and will thus forward BOTH of them.  If 
you thought SVRs were bad now... imagine duplicating some of them!

So, in the email I received, NOAA was reaching out to the wider EAS 
community (including manufacturers) for a solution.  Any ideas?

I'm likely not seeing the full picture still... but... To my way of 
thinking, there are two issues to address.  The first... the sequence of 
counties (FIPS codes) in the list... seems like an issue that NOAA could 
reasonably be expected to resolve on their end.

The second issue... regarding the included counties being different... 
would seem like something MAYBE the EAS decoder manufacturers could come 
up with a solution for.  I base that on the assumption (correct? or 
not?)... that if the list of counties isn't the same... that the NWR 
version will always be a subset of the CAP version.  And... I'm assuming 
that EVERYTHING else about the alert IS identical... same event code, 
same event time, same event duration.  And... I'm assuming that for 
unrelated reasons previously discussed on this list... that the EAS 
decoder software already... or soon will be... written to automatically 
favor CAP sources over RF sources when CAP is available... doing an 
immediate poll of the CAP server if necessary.

So... IF my assumptions above are correct... wouldn't it be relatively 
simple to modify the decoder software to favor the CAP vs NWR alerts 
from NOAA... and IF it sees two such alerts that are identical in every 
way EXCEPT the county list... to check to verify the NWR version is 
indeed a subset of the CAP version.  And if so... to forward the CAP 
version and treat the NWR version as a duplicate?  Maybe "simple" isn't 
quite the right word... but "reasonably doable"?

Ed?  Harold?

Dave