[aprssig] APRS LAT/LONG standards

Steve Dimse steve at dimse.com
Thu May 26 16:19:39 EDT 2005


On May 26, 2005, at 3:38 PM, Robert Bruninga wrote:

>>>> steve at dimse.com 5/26/2005 1:12:13 PM >>>
>>>>
>> findU uses decimal degrees, and will continue to do so.
>>
>
> Which is one of the biggest problems in APRS.
> There is no classical navigation system that uses
> decimal degrees for navigation.  ANd it is not
> the APRS standard, nor the GPS standar and it
> only causes these kinds of problems.
>
> Why do you feel it is important to be out of step
> with the rest of the GPS world, APRS and all other
> classic systems of navigation?

Why do you feel that the way you do things is the way the rest of the  
world does things?

Curt has already pointed out aircraft use decimal degrees.

APRSworld uses decimal degrees.

APRS+SA uses decimal degrees.

Steet Atlas uses decimal degrees.

Chicago Mapping uses decimal degrees.

MapBlast uses decimal degrees:
http://www.mapblast.com/(hm5scz4515qf3s55eb1rt32z)/map.aspx? 
L=USA0409&C=25.79300%2c-80.20967&A=7.16667&P=|25.79300%2c-80.20967|1| 
K4HG-8|L1|

Topozone uses decimal degrees
http://www.topozone.com/map.asp?lat=25.79300&lon=-80.20967&s=100&size=s

Acme mapper uses decimal degrees
http://www.acme.com/mapper/? 
lat=25.79300&long=-80.20967&scale=10&theme=Image&width=3&height=2&dot=Ye 
s

I do not know of a single internet service that uses degrees/minutes.

DD MM SS is a relic of a much earlier time, and likely persists to  
the extent it does because 3 pairs of digits are easier to remember,  
the DDMM.HH(HHHH) format is a hybrid relic of LORAN days. From a  
computer point of view neither makes sense, decimal degrees convey  
more precision in the same number of characters, and all calculations  
involving lat/lon are muc heasier after they are converted to decimal.

So just because you disagree, do not put the blame on me. The rest of  
the world is (gradually) adopting a standard that simply makes more  
sense. Despite KC2MMI's assertion that decimal is "some newfangled  
ISO standard" (when I first read this, I thought it was an  
hysterically funny, sarcastic comment, only on re-reading I think he  
maybe he actually meant it, either way I'm ROTFL), I'm pretty sure  
decimal has been around longer than any of us have been alive ;-)

Steve K4HG








More information about the aprssig mailing list