Ghost Coordinates

Donald E Robinson

Active Member
I'm not sure where I am supposed to post this, but, BIG problem today. I located numerous corners and roadway only to find out that I have a coordinate 3.48' from my base and 100' off on elevation. I don't know where this came from!

During setup, I selected a known point for my base station and double checked the coordinates. We located numerous corners and some highway. I load the text file in CAD only to find this coordinate point number labeled @111 with coordinates 3.48' from my base station and over 100' off on elevation. The points I located appear to coincide with the design points (Deed corners)., but, all the points I located appear to be 100' off on elevation.

Did I lose a days work? What happened?
 

Shawn Billings

Shawn Billings
5PLS
Geoid model? Ellipsoid heights vs. orthometric heights? Check your coordinate system. Does it have a geoid model?
 

Donald E Robinson

Active Member
Geoid model? Ellipsoid heights vs. orthometric heights? Check your coordinate system. Does it have a geoid model?
I check the LS and found that NAVD88 wasn't present on the Survey page. I set it to NAVD 88, and the elevation changed, but it is still out about 5'. The distance is still 3.46' apart.
The coordinate it recorded during setup was correct for Pt 3001. I don't know where Pt @111 came from.
 

Matt Johnson

Well-Known Member
5PLS
@111 is a RTN base point. It seems that you switched to a RTN profile while trying to survey point 111. The RTN Base Point will then be saved if you have this option enabled:

WHAT-TO-RECORD-SETTINGS_20190404-22.30.47.png
 

Donald E Robinson

Active Member
@111 is a RTN base point. It seems that you switched to a RTN profile while trying to survey point 111. The RTN Base Point will then be saved if you have this option enabled:

View attachment 8610
Thanks Matt. I do remember noticing the TLS recording Raw data and I disabled it.

Should I be recording the raw data, with my TLS, during my survey, and did that affect the location at 111 and those points collected after?
 

Duane Frymire

Active Member
Thanks Matt. I do remember noticing the TLS recording Raw data and I disabled it.

Should I be recording the raw data, with my TLS, during my survey, and did that affect the location at 111 and those points collected after?
You should record the raw data, don't disable it. When using the RTN you have the option to also record the virtual reference station or magical local base position; that's the very bottom button on the screenshot. It has no affect when you are in base/rover profile because there is no virtual reference station in that case.
 

Donald E Robinson

Active Member
You should record the raw data, don't disable it. When using the RTN you have the option to also record the virtual reference station or magical local base position; that's the very bottom button on the screenshot. It has no affect when you are in base/rover profile because there is no virtual reference station in that case.

Duane- Thanks for the advice.
 
Top