Curt, WE7U wrote:
On Fri, 15 Dec 2006, Jason Jordan wrote:
Off-the-record, very little QC is done with the APRS weather data
we get (mainly through the Citizen Weather Observers Program and
other various sources) into our operational weather display
software . There is a station near our office that consistently
has wind directions that are off anywhere from 60 to 150 degrees
from "official" and other APRS stations in the area and they have
done little to fix their data. Due to the inconsistency and
questionable data quality, we decided to nix importing APRS sites
into any analysis products we do. I cannot speak for other
offices across the U.S. and have heard of some NWS offices that do
collect, use, and display data for forecasting operations from the
CWOP program (which includes APRS weather stations).
I'd strongly recommend that XASTIR and APRS try to meet NWS data
standards to encourage their use in operations. Many forecasters
(O.K...at least myself) prefer more data rather than less. We
already have the capability to import the data in our operational
display system, it's just a matter of quality!
There's a club station south of here in Tacoma that was reporting
wind speeds of 125 mph yesterday when everyone else near them was
reporting perhaps 10% of that. At least my brain could do the
auto-reject based on quality for that station.
I have no problem trying to adhere to standards (I'm an engineer
BTW, BSEE). It's just that all of these weather stations put out
different standards, plus the APRS spec has standards listed in the
spec and even those don't appear to match the NOAA standards if I've
read the previous stuff in this thread correctly.
Weather people: Figure out what we want, get Bob Bruninga to bless
it publicly on the APRS and perhaps APRSSPEC list (if it differs
from the published APRS spec), and I'll help to meet those standards
in Xastir.
W.r.t. to the gust value for Clay, I'm not sure I'd want to do the
calculation any differently in a global sense. In particular I want
to keep the gust calulation code the way it is now, but perhaps
there's a different value your weather station provides that would
make a better transmitted gust value. Again, without changing the
general code.
Correct me if I'm wrong, but isn't there a generic message we can send
with data that'd not be the official APRS weather format but an addendum
to that message. Compressed format, perhaps? One of the key things we
do wrong with CWOP/APRS-class stations is report with inadequate
precision, wrong averaging constants, etc. Changing the APRS spec for
weather is probably not goning to happen top-down. I talked to Bob a
year or 2 ago and he spent a long period telling me that APRS wasn't
designed for what it's now being used for, so FMH spec didn't matter.
And that he wasn't inclined to change things, and that, since I wasn't a
s/w author, I had no real standing to request such a change...
I'd like to get Pete Loveall involved. He and I have talked some about
this...
gerry
--
Gerry Creager -- [EMAIL PROTECTED]
Texas Mesonet -- AATLT, Texas A&M University
Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983
Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843
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