Topic: State Plane coordinates to GPS survey

[mbreese]

I have a site that has topo in state plane coordinates. I also have their conversion from state plane to surface (GPS) coodinates. The city uses an excel file that divides each coordinate by the TXdot scale factor of 1.000136506 to come up with the surface (GPS) coordinate. The difference is a length of 1002.32 ft at a 70 degree angle. I have imported a USGS quad into the state plane drawing and it lines up perfect. I have published to google earth the topo that I shifted to surface coordinates and it lines up perfect.  The question is; is there really that big of a horizontal shift between the two coordinate system?

I got a topo in Oklamhoma that says it is in state plane, but the imported USGS quad and the publishing to Google earth has it 2,600 feet north of the site. How does one find the correlation between state plane and the surface to do GPS surveying.
Mark

[mjfarrell]

You will find this: http://www.i-boards.com/bnp/pob/messages.asp?MsgID=158634&ThreadID=16163&IsResponse=False
to be a good read

as will this

http://www.pobonline.com/CDA/Articles/GPS_Observer