Yes, that's what I'm saying.
950.15' x combined scale factor of .999853 = 950.01'.
That's what you're seeing isn't it?
Here is my combined scale factor for this project from my GNSS
So if I change the scale factor on the gun to 0.999853 I should line up with survey control?
For example- if I shoot in the grid lines for the project at that scale factor, then a tape check would not measure up. So our the surveyors using a grid scale and switching to the scale of 1.0000 to shoot in the grid lines? I had them shoot in the grid since I could not line up with their control. And the carpenters taped checked the points and said they were good, within 0.01'
Sorry, but the surveyors won't give me any correct info.
My process would be to occupy the control with state plane projected into my field file in the DC. When the points are located the DC correctly applies all the transformations as you're working. The TS is never tweaked. I want that data "clean".
As an aside it's difficult to understand why a project in Las Vegas would be surveyed to a projection 3000' some feet below ground. With the size of buildings and facilities I've seen there I would think actual ground distances would be the thing to do.
Grid is grid and ground is ground. Mixing the two causes problems.
On the data sheet for the provided control what does "Ground scale factor = 1" mean? State Plane Coordinates are on the grid which is not at ground level except at those locations where the grid exactly coincides with the ground, which are the exception not the rule.
"When you're shooting ground with a TS is your scale factor always 1.0000 correct?" A TS scale factor of 1.00 is for measuring distances at ground level. If you're want to measure ground distances corresponding to grid distances, your TS scale factor should be 1/CF.
In your area, the grid scale factor is 0.999929027. Using 1675 ft as the project elevation with a geoid height of -92.5 ft, the elevation factor is 0.99992423 making the CF 0.999853262. If you want to lay out a 950.00 ft grid distance, you would measure out 950.00 x (1/0.99984833) = 950.139 ground distance which is right about the 0.015 difference you started with.
Your GNSS Local Transformation parameters show CF = 1.000146512. That's the inverse of the CF: 1/CF = 1/0.99984833 = 1.00014676 which is very close to the GNSS parameter.
If you want to lay out a 950.00 ft grid distance, you would measure out 950.00 x (1/0.99984833) = 950.139 ground distance which is right about the 0.015 difference you started with.
The question is....why would someone publish control in grid coordinates in the first place?
I'll bet a year's salary that the design planset does not say "All design dimensions are in grid. Convert to ground distances using combined scale factor noted on control sheet."
Mabey this helps
and this
Sorry this
I want to be able to measure the ground distance with a TS at a scale of 1.00000 so they are true ground distance. The surveyors shot in the control points with a TS and GPS, and All I know is my TS with a scale of 1.000 doesn't match their points.
To clarify: did you use the coordinates highlighted in yellow on the control ROS that you attached?
No I did not, I dont know what system they are in, the surveyor reshot all those points
Regarding the plans you provided (drawing 00G09)... Survey note 3 is highlighted, stating "COORDINATE VALUES: NAD83 2011 (2010.00) EPOCH
NEVADA EAST ZONE".
That's grid, not ground. Apply a CSF.
Trying to make this clearer. On my CAD files, I can inverse from one building corner to the other and get the exact same number that's on the prints, converting decimal feet to feet and inches, at the same time I can click on the corner and get the northing and easting, which is exact as they are on the prints. So the state plane system must have been converted to the ground by the engineer, therefor I need to keep my scale factor to 1.00000
I just have no clue what the surveyor is doing and he won't tell me outright. But I need to line up with him
so I don't shift away from what he has already laid out. Like I stated before, getting a bust between his control.
