[Xastir] Weather Stations

Tue Sep 25 09:49:00 PDT 2018

I've become a bit of a fan of WeeWx myself. It's Pi-able so it doesn't
require a contiuously running system burning kilowatts/hr.

Caveat: I run the APRS Core and CWOP servers, and I play in meteorology for
my daily gig... I'm a bit biased.

Look at the various Davis Vantage Pro options. I'm less thrilled with the
Vantage Vue.
Peet Brothers has some good options. These two were the mainstay of the
originaly CWOP days.

AccuRite, 1-Wire Weather, there's a bunch of hardware out there. Me? I use
a Vaisala WXT-510, or will again when I replace some sensors. It's an
all-in-one based on radiosonde technology but stabilized a bit for fixed
installations.

In general, you need somthing where you can either use their software to
talk to Citizen Weather (wxqa.com; the page is antiquated, so email me if
you have problems) using the APRS-Wx protocol, or where you can capture,
and decode their data stream, and then send it yourself.

A good station will have temperature (+/- 0.1 deg F), relative humidity
(+/- 0.5%), barometer (+/- 0.5 hPa), wind speed (+/- 1 mph, 10 min avg),
wind direction (+/- 2 deg), and precipitation (0.01"/sample). A lot of
consumer stations don't meet this. Fine; go with what you find, can afford
and can make work.

CWOP is an element of the Meteological Assimilation Data Ingest Network
(MADIS), started by Russ Chadwick KB0TJV, while working at NOAA's old
Forecast Systems Laboratory, now the Global Systems Division. APRS had just
discovered weather, and Russ thought there was use in getting all those
(few hunderd, maybe) reports brought in automatically. His boss agreed, and
CWOP was born. Russ has long-since retired, as have the folks who started
MADIS, but CWOP and MADIS live on. There are weather models that
incorporate the surface data from CWOP into their data assimilation schemes
to try to improve forecasting. My group at NOAA's National Severe Storms
Lab played with it for awhile but all the extra stations translated to
"noise" and confused the Kalman filter algorithms we were using, so we've
dropped back to just using big-airport ASOS sites. Me? I think we should
have fixed the assimilation code, but I lost that battle...

We have a couple stations updating data at 30 sec, a fair number at 1 min,
and most at 5 or 15 min intervals. Once upon a time, we couldn't keep up
with rapid-update cycles, so we asked folks to back off to 15 min updates,
still better than the hourlys at ASOS sites. Servers have gotten better,
and we're in a better place now. 1 min updates are fine.

Happy hunting for a station. Just consider, if you go with something like
Accurite or Davis, they like to get your data first, then send it to CWOP.

73
Gerry N5JXS

On Tue, Sep 25, 2018 at 2:37 AM Liz <edodd at billiau.net> wrote:

> On Sun, 23 Sep 2018 21:23:55 -0400
> Dj Merrill <xastir at deej.net> wrote:
>
> > Hi all,
> >
> > Although I've used Xastir for years as an iGate, I've never played
> > with the weather stuff and have recently become interested in doing
> > so.  I'm definitely in "learning mode" right now.
> >
> > I'm running Xastir on a Raspberry Pi, and would like to find a
> > weather station that can be used with this setup, hopefully something
> > that is no more than $200-$300.
> >
> > My understanding so far is that I can connect with either serial, or
> > over the network.  My preference would be the network connection, and
> > although there seem to be several weather stations on Amazon that
> > claim WiFi connectivity, I don't know if they will support the proper
> > connectivity protocols for Xastir to connect.
> >
> > For example, this unit is attractive:
> >
> > Ambient Weather WS-2902A weather station
> >
> > (
> https://www.amazon.com/Ambient-Weather-Professional-Monitoring-Compatible/dp/B01N5TEHLI/
> )
> >
> > What exactly am I looking for to know if a weather station will be
> > compatible with Xastir?
> >
> > Thanks,
> >
> > -Dj
> >
>
> Compatible with Xastir with no additional software, or with the use of
> some other software to bridge the gap?
> Here I'm thinking of MQTT server, or weeWx.
>
> Do you just want weather "now" or do you want to archive your records?
> Weather watching is an addictive pastime.
>
> There are as many answers to the question of how can I broadcast my
> weather via APRS as there are weather station owners on this list.
> If you provide more details than a network connection and a price
> range, you will get more targeted suggestions.
>
> Liz
> VK2XSE
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>

-- 
Gerry Creager
NSSL/CIMMS
405.325.6371
++++++++++++++++++++++
“Big whorls have little whorls,
That feed on their velocity;
And little whorls have lesser whorls,
And so on to viscosity.”
Lewis Fry Richardson (1881-1953)