Land Surveyor Forum

Replies

• Land Surveyor

  Scott D. Warner, PLS August 6, 2013 at 9:43pm

  Let's forget abut context and datum for a minute and consider the simple textbook version of this.  First one must know the relationship between the, for example, proposed building and the property lines within it must fit.  Assuming that the boundary has already been established, the corner markers can be used as control points for staking the first two corners of the proposed building.  These two building corners should be the two that are farthest apart and on the same building line.  These two corners can initially be staked using GPS.  Now put your GPS unit away and get out your total station.  Set up your total station on either of the two stakes and backsight the other.  Adjust the backsighted stake for distance and now these two points are your line of control for the rest of the staking of the building.  Use each one to turn 90° angles to other corners and check your diagonal distances.  Adjust accordingly.  I hope this helps.

  -Scott D. Warner, RLS
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  Fred Franklin August 5, 2013 at 8:24pm

  It really all depends on whether you want to be on a an assumed datum or an actual coordinate system such as NAD 1983 Horizontal datum.  Most new jobs are on an assumed base unless the client specifically wants it on something else.  If an assumed datum is ok then set to control points a substantial amount apart and in in areas that shouldn't be disturbed.  Assume a bearing based on the lay of the land such as fences, centerline of roads etc.  Basically you're just trying to be close to North so that everything will plot out correctly.  Your coordinates for your starting point can be assumed as well like 10,000, 10,000.  If you need vertical, you may need to obtain a local benchmark or find the nearest 1988 NGS monument online at www.ngs.com.  Once you know the Bearing or Azimuth between your starting point and your backsight point you should be good to go.  This would all be based on assumed North and assumed coordinates.  It would be a good idea to have more than 2 control points for the project because if one gets knocked out it will be hard to get back on that assumed baseline again.  Good luck. 

  http://www.ngs.com/
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  AxeMen Site Prep August 4, 2013 at 6:35pm

  kinda difficult to comment on without understanding the context... wanna tell us what you are trying to accomplish?  give us an example?