1. The Traverse Lab ©2010, adjusted 2011 Dr. B. C. Paul Note – The techniques shown in these slides are considered common knowledge to surveyors. Figures in the slides may be the authors own work or extracted from Instrument Users Manuals, Surveying by Bouchard, Mine Surveying, or various internet image sources.

2. The Traverse Traverses carry a known point and direction forward to other points Common Problem in Surveying is that readings are taken “line of sight” Traditional instruments “line of sight” means visible light seen by human eye EDMs or GPS systems use beams of electromagnetic radiation out of human eye range Still depends on line of sight Line of Sight Problem and Triangulation Usually can’t just set up a baseline and shoot in everything you want to

3. The Traverse Technique Start with a known point And line of known direction

4. Turn the Angle Right to Your Foresight Measure the Angle to the right Backsight Az + Angle Right = Foresight Az. Measure Distance Distance and direction will allow point to be Calculated.

5. Now I Move My Instrument and Occupy Point B A B C

6. Now I Move My Instrument to Point C A B C D

7. Traverse Procedures and Variations Can see the technique can carry control around obstacles and over distances too great to shoot in one shot Common variation is to survey around a loop coming back to the point of beginning Called a closed traverse Closing Traverse checks for errors When you get back to your starting point you better have the same coordinates within a close tolerance or you screwed up (big errors called busts) Minor field variations are inevitable – there are adjustment procedures for doctoring up minor distributed errors Obviously an open traverse lacks this ability unless it ends at a point of known coordinates

8. Field Notes Traditional surveyors have had a note book in which they record the measurements Some new instruments record things digitally – but software is very specific This class have to use an Exel spreadsheet form Suggest you run it on a laptop or tablet It will do calculations for you in the field

9. The Mandatory Spreadsheet Use one copy of Form for each Instrument set-up And shot Orange, Pink, and Yellow are fields You must fill in (I have had problems With people not Recording needed Info in the past)

10. The Color Code Orange is the names you give to points you site Yellow is a measurement you must take and record while surveying Pink is for information that you either have given to you or calculate from earlier traverse shots

11. The Answer Colors Green is for a calculation the spreadsheet does Red is for an Answer Spreadsheet has calculation formulas here – don’t mess with them unless you know what you are doing.

12. Using the Spreadsheet We start out our Traverse at point A (we just happen to Know the coordinates) We set up our Instrument there and Enter this information

13. Starting Our Traverse We backsight the Center of the center Small stack on the Power plant smoke Stack We report our back- Sight and enter the known direction of the line.

14. What I Will Do From the known point and known backsight direction I will turn an angle to my first chosen point of the traverse (I will measure the angle I turned) (And the distance to the point) My spreadsheet will tell me what direction the point is in and what its coordinates are (The spreadsheet will do all the Trig for me)

15. Of course I still have stuff I must fill in. I need to measure the height of My instrument Measure from the ground up To the point at the center of Your telescope.

16. Enter The Information in Your Spreadsheet Your tape may be in feet and inches or in feet and tenths of feet. Enter one Or the other.

17. Enter Your Height of Instrument Suppose I Measure 4.5 feet.

18. Enter the Name of the First Point You Choose for Your Traverse. In this example I name my first foresight FS1. You will probably call it Something more like B or 2 (since this will likely be the next place you move Your instrument to).

19. Next You Need to Report the Angle You Turned to the Right You need to indicate what units your instrument measures angles in Degrees Minutes Seconds – Put 1 here Mills - Put 1 here Gons – Put 1 here

20. Next You Put In the Measure This is a Gon example – note the measure is in Decimal Gons. This illustrates input in degrees minutes seconds.

21. Now I Need to Record the Vertical Angle First thing I record is whether the scope reads 0 points straight up or 0 pointing exactly horizontal (except for older transits most instruments Will probably read 0 straight up). If it does read 0 exactly to the horizontal put 1 in here.

22. Now I Need to Indicate Whether I Measure in DMS, Gons, or Mills This example is for a Mill Instrument that measures a zenith angle.

23. I Now Consider How Far Away My Next Point Is I will be measuring distance by shooting with an EDM or shooting Stadia Enter 1 here if you are using an EDM Enter 1 here if you are shooting stadia

24. If I Am Using An EDM My Distance will read out in decimal feet. (Most EDMs also measure in meters but You can set that on the instrument and in this class we will be using feet).

25. Reflector Height If you aimed here Measure the height here Again you must decide whether you have feet and Inches or decimal feet. Note you simply enter which ever You have.

26. If You Are Shooting Stadia Enter 1 to indicate Stadia Then Enter the Upper, Middle, and Lower Rod Readings.

27. Make Sure Each Sheet Explains What You Did In starting my traverse I set up at a known point, backsight a known direction, Turn the angle to the next point of interest, measure the angle, measure the Distance, and calculate the direction to that next point and its coordinates.

28. Only In This Case the Spreadsheet Does the Trig for You Important things – I have the coordinates of my foresight point (I can use this To plot its location on a map). It also tells me that if I move my instrument to that Foresight point and then Backsight where I am now it gives me the direction of that line.

29. I Move Foreward to My Old Foresight Point and Backsight my Old Instrument Station My first spreadsheet gave me info I will need For my very first point I relied on someone else to give me the coordinates When I move forward to my old Foresight point I have calculated the coordinates myself

30. Start Filling Out My Next Form Where do I get the Coordinates of FS1?

31. Moving on to the Known Direction Where do I get the backsight direction?

32. Why Have a Tablet/Smartphone or Laptop in the Field If you can run the Excel sheet in the field you will get your answers as you go. If your Smartphone can run excel you can use the Smartphone as your tablet. If you don’t have a field computing device then fill in the form except the pink fields and then you’ll have to transcribe data from paper to Excel files in the computer lab.

33. The Problem of Occupying Points Traversing is good way to bring in control and dodge obstacles Could get to be a real pain if had to occupy every point of interest Might be doing a property boundary survey Property corners are key points but they might be lousy points to set up as a station Can shoot in side points from off the traverse

34. Example – Suppose You Were trying to get coordinates corner of the Engineering Building Can’t set up an instrument inside a brick wall 0,0,0 N

35. You may take some side shots Side Shot Backsight Known Initial point

36. How Do You Handle Side Shots With the Spreadsheet Just like any other point except you never occupy the “Foresight” point when you take a side shot The coordinates of the “Foresight” in a side shot will be used to plot points on the map You will not need to worry about the direction.

37. Your First Field Lab is a Traverse Around the Engineering or other Building One Team goes one way. Another the other. 0,0,0 N

38. Your Work Shoot in all the major corners of the building and the courtyard As teams converge they will shoot in a common foresight point The coordinates you have for that point should agree

39. One Special Task A and D wing Areas E Wing of Building Parking Lot A Grate

40. Side Shoot in the Grate Get the coordinates of these two Points with side shots

41. Don’t Do This A B C D E F F1 F2

42. Remember to Close Your Traverse This will be done either by traversing back to point A Or by both teams going around the building sighting and getting coordinates for a common meeting point.

43. Doing Your Lab Work The class has a folder on the Mining Department Server. Everyone has a subfolder under the class Everyone can see your subfolder, but only you have write privileges. Within 1 day of the lab you must have all your traverse worksheets done You must do a MineSight drawing showing your points and the coordinates T.A.s will check you off a day later – if you did not do the plot work you don’t get credit for that day at class

44. The Traverse Your traverse will likely take 2 or 3 class periods. At the end you will make a map combining everyones work You will have 1 week after the field work is done to compile your complete map.

45. Assigned Survey Targets Engineering Building South Side Engineering Building North Side Ag Building Neckers Communications Two dorms of choice at Thompson Point