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CWOP Location for Meteobridge Now More Precise & All about CWOP Fake LORAN

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galfert:
UPDATE: CWOP claims to use LORAN I but recently discovered that it isn't really LORAN. So every time you read LORAN in this post just change it to say Fake LORAN
But be sure to jump down to read about CWOP Fake LORAN even if this first topic doesn't interest you. https://www.wxforum.net/index.php?topic=35144.msg359840#msg359840

I discovered a bug in the way the Meteobridge converts Decimal Degrees to the format that CWOP requires (LORAN) [UPDATE: Fake LORAN, or just call its real name DM.m]. I've reported the bug to Boris and he let me examine that part of the code and I found the error and submitted a fix.  He has confirmed. Next update should fix this.

So if you own a Meteobridge and you report to CWOP your location will soon get more precise. You won't need to do anything except reboot your Meteobridge and let it load the latest version (it isn't out yet UPDATE: now available). The fix will change the LORAN [UPDATE: DM.m] location to slightly different numbers for some of you. You don't need to report anything to CWOP. Your Gladstonefamily location will not change. Only your FindU (APRS) location will change if you were affected.

You will automatically notice this fix in a few places like this:
- Your Raw data APRS packets will reflect new coordinates
- Your FindU.com Position map
- https://aprs.fi  map

This fix does not affect everyone because of the way the rounding was being done before. If you happened to luck out before and your decimal degree seconds needed to be rounded down then there was no error in location. But if you fell into the category where the decimal degrees seconds needed to be rounded up it was erroneously rounding down decimal degree seconds. This could have affected Latitude and Longitude. For example if you lived in the Northern hemisphere on West side of the Earth (like in the US or Canada) then you may have noticed your location to be a bit too far South and and/or too far East.

The LORAN coordinate system that CWOP uses is not as precise as Decimal Degrees. It also isn't as precise as Degree, Minutes, Seconds if decimal seconds are not used. The LORAN coordinate system is basically a hybrid reformatted Degrees, Minutes, Seconds with the seconds rounded off and converted to decimal. [UPDATE: Prior sentences were derived from having been misled that CWOP was claiming to use LORAN and it wasn't] Because of the format that is used by APRS it is normal to see a discrepancy in the location of around 60 feet UPDATE: they are only using 2 decimal places, if they add more digits the precision increases. But if you had a Meteobridge the discrepancy with the rounding error bug was more like 150 Feet. This was enough to put your station in your neighbors yard or across the street. So this fix should resolve some aggravation for some people.

CWOP uses this coordinate system because it uses the APRS protocol that has been in place long before it was used on the Internet and it was used by ham radio operators. So CWOP has to adhere to how the APRS protocol works. UPDATE: And there is nothing wrong or bad about it. It could be a bit more precise by adding a third decimal place is all.

If you upload to CWOP with some other software you may want to check that your LORAN UPDATE: "Fake LORAN" location posted on Gladstonefamily.net matches your Raw APRS Data packets. That is of course if the location registered with Gladstonefamily.net matches what you have configured in your software. If you notice a problem there is a chance that your software also has the same bug in their conversion formula.

Mattk:
Instead of making things backward compatible with systems like LORAN one would have thought CWOP would be better off updating their out dated 60's technology?   

galfert:
UPDATE: CWOP doesn't use LORAN ...even though they claim it is LORAN. It is just Degrees Minutes with decimal minute digits to add precision (sort of like seconds)

CWOP didn't really have a choice. The objective was about making it be backward compatible with what APRS uses. [UPDATE: Then they erroneously called it LORAN]. CWOP realized at its inception that there was a system already in place that ham radio operators were using and that was tied into NOAA MADIS. All CWOP did is integrate into an existing system (APRS). If CWOP wanted to do their own separate thing it would have required new partnerships with NOAA MADIS. And it would have required the invention of a new protocol. That would have been a much much bigger thing to have conquered. And NOAA would probably not have given CWOP the time of day for that effort at its inception. [UPDATE: These last few sentences were in response to being misled by CWOP thinking they were using LORAN] Realize that at first CWOP didn't use separate upload servers than ham radio operators. They were sharing them (but they really belonged to the ham radio people). In a short time (a few years) CWOP grew more rapidly than anyone expected. The amount of bandwidth that CWOP stations were using became many times over compared to the ham radio operators. This upset the ham radio community and CWOP had to set up their own separate servers. Again at this point the focus was to stay on the existing APRS network. Today though CWOP is so large that they could have the weight to reach out to NOAA MADIS and invent or use a new protocol [UPDATE: No need for new protocol as they aren't using LORAN. If more precision is desired all that is required is to add another decimal digit to APRS protocol]. But there is some benefit to be tied into with APRS and ham radio operators. CWOP is a volunteer network with hardly any revenue. The resources to do anything about this are not there. Just look at the web servers that they are running with decade old web server software.

CWOP is running on old outdated server software:
https://www.wxforum.net/index.php?topic=35142.msg359412#msg359412

CWOP is very different from any other weather reporting network. CWOP is just a small part of many different systems run by different organizations. It grew (or rather came to be) from the expansion of existing systems.

galfert:
The update for the Meteobridge is out. Reboot your Meteobridges people! Go to the http://aprs.fi map and watch your station jump. I've never seen a WX station move before...it showed it move on the map with a pink line just like all those other moving things you can track on the APRS network. I'm sure that pink line will disappear soon. UPDATE: The pink line was only there for a short while like maybe 30 minutes...not sure exactly.

Very happy that finally my APRS network location is finally showing more precise and not across the street.

 [ You are not allowed to view attachments ]
The APRS network temporarily added that pink line showing the move.

Mattk:
Well since LORAN is still linked to out dated weather systems then I thought I would put up the best ever thing that happened to LORAN in these modern times :) Yes I know there are some still kicking and screaming about the demise of LORAN but now other countries have also toned back upgrade plans. But LORAN can claim one distinction especially in the case of the Port Clarence, Alaska tower, the largest man made structure ever to be brought down using explosives, all 400 ton of it which was 1357 feet high, well it used to be 1357 feet high   

 https://www.youtube.com/watch?v=Cu-DFU7Xwq8
 

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