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Subject: Re: [emergency] Talking Point re CAP and CEA "Public Alert"

At 2:19 PM -0700 4/8/04, Kon Wilms wrote:
>The only compatibility I see is that at some point in time the Public Alert
>message elements can be stuffed into a CAP message for transport on headend

Right now that's right.  It's a backward compatibility challenge that 
we're addressing at the content level.  And saying CAP is compatible 
with Public Alert (or NWR, or EAS) is not the same as saying the 

Obviously it's going to take more than a couple of weeks for the 
existing public warning infrastructure to convert to CAP. 
Fortunately (and by design) it's not an all-or-nothing proposition.

And looking at it politically, if we want uptake for CAP, seems like 
we may want to avoid appearing to detract from any of the major 
existing players.  Instead, we may want to emphasize how CAP can make 
existing systems even better.  Over time, I'm confident the benefits 
of CAP will become clear to everyone and its use will become more 

>It isn't compatible with the NWS system from the point where one can just
>take an NWS message like EMWIN products and stuff them into a CAP file.

True, because NWS doesn't enforce strict structures for their text 
products.  The current NWS text system comes from a tradition of 
"rip-and-read" teletype copy meant for human reading, not for easy 
computer processing.

NWS management are well aware of the huge variations in how different 
forecast offices format their products, but it's a huge organization 
and change takes time.  Besides, until now there wasn't an industry 
standard available... and the current administration is very much 
oriented toward industry-generated standards.

There's been progress:  The LAT...LON convention for describing 
precise target area coordinates in "short fuse" warning products is 
being used pretty consistently... and the "bullet" format used by a 
number of offices for warnings can be mapped fairly precisely into 
the component elements of a CAP document.  And their experiment using 
CAP suggests that NWS is actively considering moving to more 
structured formats.

But in the meantime it's a little like copying VHS to DVD... the 
output product can't be any better than the input.  The best we can 
do is make sure that we can accurately reflect the input, however 
structured or unstructured it may be.

>I don't see any CAP compatible files coming over the GOES satellite feeds
>(thats the real stuff I care about - test feeds are good for demo only).

NWS has a whole process they have to go through to adopt new 
technology.  The first step is an "experimental" service, which is 
what they're doing now.  So if you want CAP feeds by satellite, I'd 
encourage you to communicate your support to Bob Bunge in the NWS 
CIO's office (<robert.bunge@noaa.gov>) so he'll have ammunition to 
persuade his management to take that next step.

>CAP and XML in general is also
>too wordy to transmit quickly at a low datarate - the 3000+ products that
>are transmitted at 2400 and 9600bps over GOES would never come through in a
>timely fashion if they were all reformatted to CAP spec.

This objection comes up regularly... but as you've demonstrated, XML 
compresses really well, and that's a fairly routine, standards-based 

>CAP is only compatible with the NWS system when the NWS decides to reformat
>all their products to CAP and starts distributing them over their satellite
>feeds. This is just my opinion, however.

Get your point, but I think that may be putting the shoe on the wrong 
foot.  We're the new guys on the block, and we're taken pains to be 
compatible with the old established systems.  We can hope to see a 
migration toward more modern methods as the benefits of CAP are 
demonstrated, and as consumers start asking providers to make the 

- Art

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