Land Surveyor Forum

Replies

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  Arnel M. Domag October 15, 2010 at 10:36am

  To my opinion, your question is incomplete as to what coordinate system is employed and how large is the area to stakeout. If we're talking here of large area then projection (convergence, scale factor, etc.) plays very important role. If area is small with two given points of known local coordinates then plane trigonometry approach can do the the job as far setting out is concerned but falls a bit short on mapping/cartography since mapping strictly involves projection. If area is small with only one given point with known local coordinates then you're in trouble. The problem in this case is how to determine the grid or local orientation and the scale factor and convergence values associated with it. The safest approach is to relate those given coordinates with a strong network nearby.
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  ronnie r. monilla RCE,JGE,CSP October 14, 2010 at 8:58am

  dnt stake out, you will create yourself some trouble if not by your client, neighbouring lots owner, lastly the state board itself when these people complains. two points is not enough you must have at least a third point to check the correctness of your benchmark before proceeding to SO.
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  Michael Alan Sanchez September 20, 2010 at 11:43pm

  You need a least 3 points in agreement to do so. Polaris, sunshot or geodetic could be used as basis of bearing and eliminate one point. Make the client sign a waiver of guarantee and only offer warrantee (free restake if wrong)
  the best way is to locate as accurately as you can (static GPS, or if under 1000' a 3 second total station).
  locate the points using geodetic, polaris or sunshot for basis of bearing, then place in CAD, make block of points, move to known coordinate for one, then determine rotation for other point, if rotation is more then a 1/10000 (20") you will need to rotate to project coordinates, if not just split the error by creating a line between the two shot points and the two plan coordinate points and moving the block over to the midpoint of the line, if you have more points then you can do a "best fit solution by rotating and scaling the block to fit.
  When you have the scale factor (difference between shot and fit block) put that in the data collector so all new shots are automatically scaled, check by staking out the know points.
  
  PS 20" may be excessive for some jobs, such as nuclear reactors and linear acceralators or large metal assemblies.
  
  PSS don't stake anything within a few tenths of the plan boundary or limits without a proper boundary survey.
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    Alexander Skripkin > Michael Alan Sanchez September 21, 2010 at 2:27pm

    It seems I was wrong in understending the question, am I right? :-)
    Anyway, in this case, Michael, why can't I pick all points I need from the plan (using arbitrary (z) coordinate system)(as I can see, all information he has is on paper - look for query), than, in fields, to make a resection using these coordinates and than to stake out all other points (using my "z" C.S.). Amount of points gives me the statistics. It seems to me much easier than your solution. Of cause it works bad for nuclear reactors but for farm boundaries its enought.
    Or may be I'm wrong in unersending again? :-(
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  Alexander Skripkin September 20, 2010 at 5:35pm

  - Or we can swear with the customer
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    ronnie r. monilla RCE,JGE,CSP > Alexander Skripkin October 14, 2010 at 9:09am

    you must always connect to an established network or you will find yourself contested by it. you must know the difference between grid and ground coordinates. especially when using gps 3 points is a must if you want to conform with existing network otherwise you are creating your own network. whatever, the state board has the last word.
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    Ahmad Haroun > Alexander Skripkin September 21, 2010 at 2:45pm

    it's the best way ...!!
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  Alexander Skripkin September 20, 2010 at 5:32pm

  - The easiest way is to use GPS RTK system with the base at the point we have. Of cause it works if the coordinate system is well known (7+5).
  - We can use resection if it is possible
  - If we have 2 or more points known (far from each other), we can make traverse throw them, calculate step points and next time to perform the stake out
  - If the accuracy is not primary thing for our job, we can use total station and surveying compass. In this case we need just one control point. Or we can use Garmin :-) In this case we need nothing.
  
  The correct way to do this stake out is to create new benchmarks for this site!!!