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Shift in coordinates

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(@on_point)
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I was tying into control from a previous survey which was supposedly done in NAD83 and the coordinates I was given looked like SPCS but when I staked out to the control there was about an 8.5ƒ?? shift between the two surveys. Only explanation I can think of is the previous job was started on an assumed point on a SPCS job. Anyone else run into anything like this?

 
Posted : 09/06/2023 7:26 pm
(@norman-oklahoma)
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Regularly. 8.5 feet sounds to me like the job is based on an autonomously positioned GPS base station. 

 
Posted : 09/06/2023 8:18 pm
 Norm
(@norm)
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Also two other possibilities

1 Scaling to ground from 0,0 origin

2 international feet units

 
Posted : 10/06/2023 3:34 am
(@rover83)
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Another possibility is using ITRF rather than NAD83 for the geodetic basis. Seen that happen quite a few times.

 
Posted : 10/06/2023 5:30 am