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Mark Howe
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Username: unclemark

Post Number: 377
Registered: 08-2003
Posted on Monday, April 21, 2008 - 11:07 am:   Edit Post Print Post

I just posted some notes on the Saddleback GIS Discussion section about creating maps of GPS tracks and points using the capabilities of ExpertGPS and ArcView, such as we use in the Saddleback classes. Our standard xy datum is WGS84 which is the default for most GPS nowadays.

I was unable to find a discussion I recall recently on this site regarding geographical datums. WGS84 was compared to NAD83 as I recall.
My input is that comparing the two I have been unable to detect any difference between them. I have heard there is perhaps a 4ft discrepancy. Another fairly common datum is ITRF00 which I understand is an update of the WGS84 datum updated to 2000. The last two OOs are actually 00s [zeros]. [I used to pronounce it iterfu].

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