Comments on CAP Example Practices Document

["Elysa Jones" <elysajones@yahoo.com>]

Friends,

 

Eliot Christian a CAP subject matter expert was asked to review and comment on the CAP Example Practices Document during the subcommittee drafting of the document.  He provided edits to Tony’s version and this was reviewed with several members on a call today (Yu, Tony, Gary Ham, Eliot, Elysa).  The comments were well received and all agreed the discussion should continue on the regular Collateral and Documents SC call 1/8.

 

It should be noted that Eliot is not an OASIS member but is commenting as a subject matter expert.  He will be attending the call in that same capacity.  He understands that anything he provides is a free contribution with no encumbrances from an IP standpoint. 

 

There are five additional items Eliot would like the SC to consider adding to the document as follows:

 

(1) Urgency, Severity, and Certainty - Every CAP alert SHOULD

have values other than "Unknown" for Urgency, Severity, and

Certainty. In practice, it appears that CAP implementations

treat "Unknown" as "insignificant". So, a CAP alert could

be ignored if the value "Unknown" occurs in these elements.

 

(2) The terms "Advisory, Watch, Warning" are not used consistently

across hazard types with respect to the separate CAP aspects

of Urgency, Severity, and Certainty. Given that NWS is currently

considering revisions (see http://nws.weather.gov/haz_simp/ ),

now may not be a good time to discuss good practice for these.

 

(3) Geographic location - In ATOM and RSS, I suggest including

the cap:area element with its sub elements exactly as coded in the

actual alert (e.g., see http://www-db.wmo.int/alerting/atom.xml

and http://www-db.wmo.int/alerting/rss.xml )

 

(4) Geographic Precision - Discuss the widespread misapplication

of overly precise coordinate values, often far beyond realistic

accuracy. (CAP 1.0 contained a "Coordinate Precision" Note but

it was dropped in 1.1, apparently by an editing error?). Also,

the use of zero for a circle radius should be discouraged as it

implies a geometric point but in reality should be comparable in

scale to the precision implied by the circle center coordinates.

 

(5) Other Geographic Notes - Perhaps discuss closure of a polygon,

winding order of polygon coordinates, and validating polygons?

Aside: Is there a note on how best to indicate the whole earth

(e.g., for many space weather hazard threats).

 

We will see you all on the call tomorrow.

 

Elysa