www.pc-wetterstation.de

Hi Werner,

It seems the aprs.txt file contains the current value for the wind speed. There are two common standards for reporting wind:

APRS standard
wind speed - average for 1 minute.
wind gust - high gust during past 5 minutes.

NOAA standard
wind speed - average for 2 minutes.
wind gust - high gust during past 10 minutes.

Is there a way specify which wind data is placed in aprs.txt?

Thanks.

Steve
-----------------------(Google Übersetzung)
Hallo Werner,
Scheint es, daß die aprs.txt-Akte den gegenwärtigen Wert für die Windgeschwindigkeit enthält. Es gibt zwei allgemeine Standards für das Berichten über Wind:

APRS Standard
windgeschwindigkeit - berechnen Sie für 1 Minute Durchschnitt.
Windboe - hohe Boe während der letzten 5 Minuten.
NOAA Standard
windgeschwindigkeit - berechnen Sie für 2 Minuten Durchschnitt.
Windboe - hohe Boe während der letzten 10 Minuten. Gibt es eine Weise spezifizieren, welche Winddaten in aprs.txt gelegt werden?

Danke. Steve

@Steve,

I didn't know that.

I will change this.

Werner

It would be good if we could choose which standard we want for our APRS data. I submit to APRS mainly so I can feed into the NOAA mesonet, so I would like to be able to use the NOAA standard.

Davis WeatherLink only fills in the rain since midnight for their APRS support. I notice that WsWin provides all three rain values (1 hour, 24 hour, and since midnight) in the aprs.txt. Since it hasn't rained since I started using WsWin, I haven't been able to see if WsWin actually fills in real data for the 1 hr and 24 hour rain. It would be great if it does?

Thanks!

Steve

to assist your support of APRS, I'm including these references:

APRS specification
http://web.usna.navy.mil/~bruninga/APRS ... OTOCOL.TXT
http://web.usna.navy.mil/~bruninga/APRS-docs/WX.TXT
discussion of some APRS weather issues
http://web.usna.navy.mil/~bruninga/aprs/spec-wx.txt

I've snipped out the part about weather here:

WEATHER REPORT: APRS uses the underline symbol character for WX reports.
For these, the COURSE/SPEED field is used for the WIND and the remainder
of the comment line contains other weather items. See WX.TXT
@DDHHMM/DDMM.hhN/DDDMM.hhW_CSE/SPDgXXXtXXXrXXXpXXXPXXXhXXbXXXXXdU2k
r is in hundredths of an inch of rain in the LAST HOUR
p is in hundredths of an inch of rain in the LAST 24 HOURS
P is in hundredths of an inch of rain since midnight
s is INCHES of snow in the last 24 hours
b is in tenths of millibars
h is percent humidity (00=100%)
dU2k is Ultimeter 2000, /U5 is the 500 and /Dvs is Davis
The "d" means it is running DOS
Lxxx is luminosity in Watts per square meter 999 and below
lxxx is luminosity in Watts per square meter 1000 and above
L is inserted in place of one of the rain values.

(from wx.txt)
_CSE/SPDgXXXtXXXrXXXpXXXPXXXhXXbXXXXX%type
NEW FORMAT APRS793 June 97 NOT BACKWARD COMPATIBLE

Where:
CSE/SPD is wind direction and sustained 1 minute speed
t is in degrees F
r is Rain per last 60 minutes
p is precipitation per last 24 hours (sliding 24 hour window)
P is precip per last 24 hours since midnight
s is snow
b is Baro in tenths of a mb
h is humidity in percent. 00=100
g is Gust (peak winds in last 5 minutes)
# is the raw rain counter for remote WX stations. See notes on remotes
% shows software type d=Dos, m=Mac, w=Win, etc
type shows type of WX instrument

I am guessing that VWSaprs takes the second line from the aprs.txt file, prepends the station id, date/time, etc. and appends "v31" (used to idenity the providing software/hardware). So I think the aprs.txt file only needs to contain this part on the second line:
CSE/SPDgXXXtXXXrXXXpXXXPXXXhXXbXXXXX
and there is the possibility to add the snow and luminosity information as well.

Many using APRS to feed to CWOPS would want the option to select 2 minute average wind and 10 minute gust since that is the NOAA preference.

Steve

@Steve,

in case of

Lxxx is luminosity in Watts per square meter 999 and below
lxxx is luminosity in Watts per square meter 1000 and above
L is inserted in place of one of the rain values.

where is this value set or is it appended

Example:
Oct 16 2005 14:46
301/005g012t051r000P000p000h36b10215

Werner

I did a test, and VWSaprs does not handle it correctly if you append it. However, I looked at other packets, and they put it after the "t" tag. Here is an example of an "l" tag:
CW2005>APRS,TCPXX*,qAX,CW2005:@161550z1824.25N/06602.40W_130/004g006t088l1087p000r000b10109h75.DsVP
and an "L" tag:
CW2037>APRS,TCPXX*,qAX,CW2037:@161556z3953.02N/07500.95W_299/002g008t061L158P000h55b10051.DsVP

I did a test by manually editing the aprs.txt file produced by wswin and letting VWSaprs send that. Here is what was received by APRS:
CW4409>APRS,TCPXX*,qAX,CW4409:@161538z4344.92N/11635.30W_313/002g003t048L100r000P000p000h66b10233v31

It seems to have worked good!

So if you pass something like this:
Oct 16 2005 15:38
313/002g003t048L100r000P000p000h66b10233

in the aprs.txt file, it should work

I don't know about the "s" snow tag. I have not been able to find a packet containing it.

I hope this helps.

Steve

Hi Werner,

Thank you for adding the APRS/NOAA standards. That was a very fast response and support!

I have been checking out the APRS portion of the new version and I think I may have found two minor problems that may be related.

1) I'm not sure how you calculate the 1 and 2 minute average wind, but it appears that the value that gets put into aprs.txt is one minute behind. For example, with this data:
time wind
08:23 4 mph
08:24 2 mph
08:25 1 mph

the aprs.txt file for 08:25 will have a value of 3 mph.

2) I'm using the NOAA standard, which specifies that the wind gust is the highest gust during the past 10 minutes. WSWin seems to be off by 1, giving the gust over 11 minutes. I'm seeing results like the following:

time / wswin gust / aprs.txt gust
08:19 03 03
08:20 06 06
08:21 04 06
08:22 05 06
08:23 04 06
08:24 04 06
08:25 03 06
08:26 04 06
08:27 04 06
08:28 03 06
08:29 03 06
08:30 02 06 <-- this should be 05
08:31 03 05
08:32 02 05 <-- this should be 04

I don't know how good your english is, but I'm sure it's better than my German. Sorry I can't post in your native language. I hope this doesn't cause you a problem.

Thanks.

Steve
p.s. I'm curious which tool you use to program WSWin. Is it Delphi?

@Steve,

I need to verify the max value.
This value is build from the available last data and not from the Online-Data.
The 1 and 2 minute values are build from Online data - if there was data received - if there wasn't any data in this range received the program using stored data (Weather stations like LaCrosse WS2500, here is the minimal storing interval 3 minutes).

My compiler is at the moment Delphi 5.

English - no problem.

Werner