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Weather Related Organizations => CWOP Forum => Topic started by: DJMWX86 on April 03, 2020, 01:45:44 PM

Title: APRS issues
Post by: DJMWX86 on April 03, 2020, 01:45:44 PM

Hi all.

My APRS software that I'm using 2.0.2.0 seems to be throwing off  my station position compared to my registered location which is correct on my CWOP map. It looks like because it does not have the "seconds" field in the coordinates it's putting my staton out a mile away then where it is. Would this account for the discrepancy? Do I need to download a new version of APRS if there is one? I'm using VWS 15.00/weatherunderground and that part/location info is fine it's just the APRS location I'm having issue with. Any help would e appreciated.

Title: Re: APRS issues
Post by: galfert on April 03, 2020, 04:43:27 PM

Looks to me like your VSWaprs Station Info tab is not configured correctly.

You probably have the following entered:
Latitude: North 41 Degrees 26 Minutes
Longitude: West 81 Degrees 26 Minutes

You should change it to:
Latitude: North 41 Degrees 26.60 Minutes
Longitude: West 81 Degrees 26.59 Minutes

The APRS protocol does not use seconds. It uses Degrees and Decimal Minutes. Or also referred to as DM.m notation. Basically what amounts to seconds are in decimal form of minutes.

I can see from your raw APRS packets that you are not sending the decimal part of the minutes:
http://www.findu.com/cgi-bin/raw.cgi?call=CW2334
CW2334>APRS,TCPXX*,qAX,CWOP-2:!4126.00N/08126.00W_323/004g010t049r000P000p000h59b10152.VWS-DavisVP2

VWSaprs expects you to enter the location information just as the APRS protocol needs it...in DM.m format. Some other APRS software will accept Decimal degrees or Degrees Minutes Seconds which are more popular to deal with and then these other software do the conversion to the format that APRS uses. Unfortunately with VWSaprs you have to do the conversion yourself and then enter it in the format that it expects.

I use this website to do these conversions:
https://www.directionsmag.com/site/latlong-converter/

But you can also refer to your Gladstonefamily.net analysis station webpage and see your registered station location in all three formats:
https://weather.gladstonefamily.net/site/C2334

Here is a good setup guide for VWS and APRS:
https://www.weather.gov/media/epz/mesonet/CWOP-VWS.pdf

Title: Re: APRS issues
Post by: galfert on April 03, 2020, 09:53:52 PM

Perfect. Fixed.
CW2334>APRS,TCPXX*,qAX,CWOP-1:!4126.60N/08126.59W_330/000g000t041r000P000p000h77b10160.VWS-DavisVP2

You are currently uploading every 10 minutes. You can change that to every 5 minutes if you'd like.

Title: Re: APRS issues
Post by: DJMWX86 on April 04, 2020, 12:12:52 AM

Yep just looked at it. Thanks for your help  [tup]