California Surveyors Forums

I am trying to calibrate to some published points from a Record of Survey.

http://www.cityofsacramento.org/transpo ... Survey.pdf

On page 5 of the Record of Survey , there are 3 points (G3708, G3707 and G3607) with only horizontal coordinates, I would like to calibrate to using my Sokkia GRX1, TopSURV (8.0) and connected to my local Topcon RTN. I also need to establish some vertical control onsite. Here's the bench mark:

http://www.cityofsacramento.org/transpo ... umber=2395

BM: 278-B4A
ELEV: 42.608' NGVD29

How can I incorporate this horizontal and vertical control into my localization. I tried to calibrate to one point G3708, but my results were off.

PT NORTHING EASTING INVERSE
TOPCON (205) 1991335.266 6725462.330
TOPCON (3708) 1991336.971 6725458.872
deltas -1.705 3.458 3.86


I also need to set two control points onsite because of some really big trees. I want to set these two control points and then hook up my total station (Sokkia SET630R) to my FC236. Since the GPS is on grid I would need to apply a scale factor to my total station measurements.

Looking forward to your responses.

Thanks,

Nick

I resurveyed the points from yesterday, adding one more control point. I keyed in the coordinates 101, 102, 103, and 104.

101 CONTROL Mon LR 208
102 G3708
103 G3707
104 G3607

After keying in the coordinates, and selecting the Projection to SPC83-California(Zone2).

Then under Setup Localization, I specified the local coordinate 101 and the measured point as 201. Message appears:

Known point 101 is not local. Only points in local coordinate system can be used as known point.

Do you want to create point 101_loc with local coordinate obtained from 101 using suitable grid to ground transformation?

Select <YES>. I then surveyed the remaining 3 other points 102, 103 and 104. And this time my results were much better, see results below:


PT NORTHING EASTING INVERSE
101_loc 2001003.31 6736639.57
101 2001004.73 6736636.29
deltas -1.42 3.28 3.57




101 2001004.73 6736636.29
201 2001003.32 6736639.56
deltas 1.41 -3.27 3.56




101_loc 2001003.31 6736639.57
201 2001003.32 6736639.56
deltas -0.01 0.01 0.02




102 1991335.27 6725462.33
202 1991335.22 6725462.34
deltas 0.05 -0.01 0.05




103 1990715.40 6719598.77
203 1990715.43 6719598.77
deltas -0.04 0.00 0.04




104 1985542.90 6724531.87
204 1985542.90 6724531.80
deltas 0.00 0.08 0.08




104 1985542.90 6724531.87
304 1985542.92 6724531.80
deltas -0.02 0.08 0.08




204 1985542.90 6724531.80
304 1985542.92 6724531.80
deltas -0.02 0.00 0.02

Problem solved.