[juneau-lug] GPS mapping datum

  • From: Jamie <jamie@xxxxxxxxxxxxxxxxx>
  • To: juneau-lug@xxxxxxxxxxxxx
  • Date: Mon, 08 Nov 2004 12:52:15 -0900

Yes, there are many mapping datums world wide that exist to correct the 
curvature flaws for exactly the reason you identified.
My GPS is currently set to NAD83.  But I did cycle through the whole 
list of mapping datums that this GPS supports (about 50?) and none of 
them corrected the error I was seeing.  So I think it must be something 
additional.  The coordinates we get from the geocaching hunts work 
perfectly, so I don't suspect a GPS error.  It has to do with 
translating to the map coordinates.  And as I mentioned, the error is 
evident in programs besides GPSDrive.

Kevin Miller wrote:

>>In downloading the waypoints and tracks I found a bug in the perl
>>script that converts the data for GPSDrive.  If that's any use to you
>>- I'll dig it out and send it.  Also I'm perplexed as to a map
>>syncing error in GPSDrive that consistently throws off my position
>>(maybe 400 ft WNW).  I see the same error in MS Streets & Trips. 
>>Anyways lets compares notes sometime - at a JLUG meeting or otherwise.
>>    
>>
>
> What NAD ("reference datum") is your GPS set to?  I don't understand it
>exactly, but apparently there's a couple different NADs; NAD27 and NAD83.
>Mixing them throw off the reference by a few seconds (60' per second I
>believe).  I think it has something to do w/trying to map a curved surface
>(the earth) to a flat piece of paper.  Or it could be something else
>completely...
>
>
>...Kevin
>  
>

-- 
Browns Homepage  http://jdb.homelinux.net


------------------------------------
This is the Juneau-LUG mailing list.
To unsubscribe, send an e-mail to juneau-lug-request@xxxxxxxxxxxxx with the 
word unsubscribe in the subject header.

Other related posts:

  • » [juneau-lug] GPS mapping datum
  1. Home
  2. juneau-lug
  3. Archive
  4. 11-2004