Looking for explanation for datum and conversions

In my limited experience with changing datums, here in the northeastern US, I have seen offsets between NAD27 and WGS84 (NAD83) to be around 600' North-South and 60' East-West. This however will vary greatly with location.

I've found some useful information on the subject from a post at Geonet.com :

https://geonet.esri.com/thread/29708

The National Geodetic Survey website offers a conversion formula:

http://www.ngs.noaa.gov/cgi-bin/nadcon.prl

I've found it to be a bit awkward to use effectively in some cases. You can substitute WGS84 for the NAD83 coordinates since the offset between the two datums is less than 3' in most of North America.

Wikipedia also offers some basic information on the subject:

https://en.wikipedia.org/wiki/North_American_Datum

Thank you - I'll check out those resources

Steve

The FCC has tools to convert the datums as well. They use coordinates for the location of transmitter antennas and some were originally posted in NAD and have to be converted to WGS.

If you have a Windows computer, there is a free conversion utility called Fizzycalc that is used a lot by geocachers to do various datum and coordinate conversions, distance calculations, projections, etc. Just Google Fizzycalc and you will find it.

Thanks Alan and Box car

This is a good site. Thanks!

Thanks for the website. Bookmarked!