[aprssig] MultiLine Weather Object parsing
Lynn W. Deffenbaugh (Mr)
ldeffenb at homeside.to
Wed Feb 23 12:34:22 EST 2011
I'm having trouble decoding a MultiLine weather object from WXSVR-AU,
specifically the following (Skip half way down for my actual question):
CWSBFU>APRS,qAS,WXSVR-AU:;CWS0515zA*250515z3226.08S/14834.20E:
}05DEBRNWYXPLDE{N5FAA
According to what I understand from
http://www.aprs-is.net/WX/MultilineProtocol.aspx and
http://www.aprs-is.net/wx/, this breaks down as:
CWA: CWS
Product: BFU
Object: CWS0515zA which is:
CWA: CWS
ttttz (issue time): 0515z
Line number: A
DDHHMMz (expiration time): 250515z
Lat/Lon is obvious and symbol is /: or Fire.
MultiLine: 05DEBRNWYXPLDE
Sequence: N5FAA which is:
DHM: N5F (Day 23, Hour 5, Minute 16
Uniqueness: AA
All of this makes sense (except for the off-by-one-minute issue times),
but it's inside the MultiLine that I'm having trouble.
05DEBRNWYXPLDE
appears to be missing the first character indicating the type of the
line which should range from a to l (lower L) (at least, according to
http://www.aprs-is.net/WX/MultilineProtocol.aspx that's what's supposed
to come first).
If I ignore that, then:
0 = Closed Polygon
5 = Scale
followed by 6 lat/lon offsets of DE BR NW YX PL DE
So, is it safe to say that if the first character is not a through l,
then the line type is not specified and interpret the remainder if the
lengths and such make sense? It's actually my "length must be odd"
check that's stopping my parser at this point, but that's just as well
because 0 is an undefined line type.
Is there any other APRS client application that actually interprets and
displays MultiLine objects like these?
Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32
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