ROBOTIC TOTAL STATION SURVEYING

ROBOTIC TOTAL STATION SURVEYING

        Robotic Total station surveying : is a modern total stations which is no longer require a reflector or prism (used to return the light pulses used for distancing) to return distance measurements, and can even e-mail point data to the office computer and connect to satellite positioning systems, such as a Global Positioning System (GPS). Though real-time kinematic GPS systems have increased the speed of surveying, they are still horizontally accurate to only about 20 mm and vertically accurate to about 30–40 mm.

        Protocols for setting up the Leica 1200 TST

        The locations of Station- and Backsight points should be known to you.

Ensure that the station co-ordinates are written down clearly and stored in the Total Station.

       A few notes:

Survey Book

– You must write your setup information into the survey

book – this will be:

– Job identification: In the format: Projectddmmyy

– Machine height: measured from the top of the station point to the small carved grove on the side of the machine. You must measure accurately to the nearest millimeter. It has proven useful to attach a metal bracket to the top of the station point which enables vertical measurements and avoids inaccuracies through bending the tape measure

– Station used

– Backsight used: This should preferably be a station point located at a considerable distance

(~100m+) from the Total Station, as this achieves more accurate overall measurements.

– Your numbers must be clear and unambiguous and your writing legible, as it may not be you

who processes the data.

End of survey

– Hit “ESC” a number of times to exit the survey interface and return to the main menu on the remote control.

– Then press and hold “ESC” to turn off the remote control.

– Press and hold “ESC” on the Total Station to turn it off as well.

– Ensure that the Velcro or clip on the tripod is done up properly, otherwise it poses a health and Safety risk.

– Remove the batteries from the Total Station the remote control and the big red external battery and charge them using the Leica charger in the survey cabin so everything is changed for use the following day

      Weather conditions

– If it rains there is a yellow cover to put over the machine when it is not in use. This will then be folded and rolled up and put in the anti-glare cover (the black plastic cylinder).

After a day out in the rain, the machine must be taken out of the box to dry out, the yellow

Cover and the box also need drying out.

– If the Total Station is in danger e.g. blowing over in the wind, being knocked over by passing

Vehicles, then take it down. It should not be left unattended on site. If everyone goes in for

lunch and the machine is out of sight of the cabin, take it down. If you are in a public place

(Park, city centre etc.) and you go in for lunch, take it down.

      Survey Setup

Setting up the Total Station

Remember to set up the survey equipment to your own / a person's average height – make sure you can see through the viewfinder whilst stood on all sides of the instrument.

 

                                       STEP1: Go to the station point to set up theTotal Station 

Spread the legs over the point so that the plate is level, and the hole of the screw over the point. Please note that the plate does not have an actual level, but that this is only for initial judgment by the eye.

Press the pointy ends of the legs firmly into the ground, ensuring the tripod stays level Undo the tripod legs and raise to roughly chest height.

      Tighten the screws / clips.

 

Open the red box, and take the machine out by the handle. Do not let go of the machine until it is

Firmly attached to the plate!

Line the base of the machine with the plate and screw up the screw on the underside of the plate

Clip the big red external battery to the tripod

Clip the black radio transmitter to the tripod and connect them using the black cable: the larger of the three ports goes into the battery and the other two into the Total Station and the radio. Line up the face of the machine so that it is parallel with one of the feet and the back of the machine has two feet spreading from its centre point

 

. Press the ‘prog’ button to switch on the Total Station

 

Press ‘shift’ - ‘F12’. This will activate a laser plummet in the form of a red dot on the ground. Twist the feet on the tribrach to position the Total Station directly in the centre of the statio point.

Now look at the bubble above the screen. By adjusting the height of the legs, one at a time, get the bubble roughly in the middle of the spirit level. Have a look at the laser, you may need to twist the wheels again as the laser plummet can move off the nail. Now use the feet to make fine adjustments to the bubble.

The front two feet are turned together, but in opposite directions, the back foot is turned by itself. Watch the screen as it will give you a numeric value to your machine tilt as well as having a useful picture to watch. Once the machine is within acceptable levels of tilt (around 0.003 in each direction), check the laser again. Now check the level one more time. Press ‘cont’.

 

Measure the height of the station point by taking a reading from the top of the station point at a 90°bangle to the metal bracket attached to the screw to the groove in the side of the instrument (above the Optical Sticker in the image below). You must measure accurately to the nearest millimeter. Write this value into the survey book.

   

 

          Step 2: Setting up the remote control

Ensure the black antenna is attached firmly to the handset. Turn on the instrument by pressing and holding the “prog” button.

            The radio link is between the Total Station and the remote control is activated instantly.

You can no longer use the Total Station's keypad (except for checking the level by pressing shift + F12), everything is now done from the remote control.

             The following only applies when you intend to use a 360° prism:

Take the detail-pole with the black platform attached to it and clip the green handset onto the

panel by clipping the back to it and pushing it down.

              The red button is pushed upwards to secure the handset on the panel. It is worth considering the use of a small circular Leica prism with a constant of 17.5mm, as this can be lowered so it closer to the ground and thus easier to level.

In this case one carries the remote control with the black elastic strap attached to its back (unless it is preferred not to use this strap). 

  

               You can either use the arrow keys to highlight an option, and press enter, or press the corresponding number (not the F keys though)

              Use the arrows to highlight ‘1 Survey’ and press enter, or press ‘1’

         The job line is highlighted. Press Enter (the red button) 

Now press ‘F2’ - ‘New’. 

 

Creating a new Job:

– The Name is the job title, ‘Project’, followed by the date, eg Project 050609

– Creator is your initials

You will notice near the top of the screen that there are several tabs. The page - F6, button will

Switch between the different tabs.

– press ‘Page’

– ensure that the codelist the one you were assigned to use on your project. Use the left and right arrows to select the correct one

– Press ‘Page’ again

– ensure the Coord system is OSGB36 (2)

– Press ‘Store’

– You will see a list of jobs stored in the machine.

– Make sure your job is highlighted

– Press ‘F1’

Ensure that the EDM / ATR settings are set to the same default 

The Setup procedure (after job creation)

Now you must press ‘setup’

This will take you to a page where you set up the station information

 Choose the method “Known BS point” and the Station Coord. “From Fixpoint Job”

- this is the job from which you retrieve the station information.

 The station information for jour job should be stored on a job called ‘ Project_Control’.

Type in the instrument height just measured off the Total Station after writing it into the survey book. Press cont.

 

Station Coord - From Fixpoint Job

Station ID - chose OAN1

Instrument Height - measure from the top of the station point to the groove on the side of the

machine, just below the word Leica (see above).

Computd Scale – 0.9996012717

        The “Computd Scale” is a factor that needs to be taken into account on any site. Should the site in question be a large one, such as a long road scheme, the coordinate system has to be defined as OSGB32 (02) and the scale should be 0.9996012717.

        If, however, the site is small, the coordinate system does not even necessarily have to be defined, and the scale should be 1.000000.

 

   Step 3:    

        Setting up the Backsight Prism You need one tripod and the orange box containing a circular prism and tribrach.

       Undo the tripod legs and raise them.

       Tighten the screws. Spread the legs over the point so that the plate is level, and the hole of the screw over the point Push the pointy ends of the legs firmly into the ground,ensuring the tripod stay level.

   

 

       Open the orange box, and remove the circular prism. Turn the prism to face the Total

Station on the station point.

      Line up the base of the prism (tribrach) with the plate.

      Do not let go of the prism until it is firmly attached to the plate.

 

          Do up the screw on the underside of the plate.

         Now level the prism using the wheels at the base of the tribrach, ensuring the prism remains over the backsight point.

 

          Look through the small viewfinder to the side of the tribrach and move it so the target is directly over the backsight point

       The procedure described above is basically exactly the same as that for setting up the Total Station, using the feet on the tribrach and the legs for levelling and positioning.

      Measure the height of the station point by taking a reading from the top of the backsight point to the midpoint of the prism. You must measure accurately to the nearest millimeter.

      Write this value into the survey book. In this case, again, it is worth attaching a horizontal bracket to the point.

After last pushing “cont” a page was brought up that allows you to shoot to your backsight. Select your backsight point as your Backsight ID from the submenu.

    Now enter the Reflector height – this is the height you measured off the prism.

   Press ‘Dist’

   Check that the Horiz Dist and Ht Diff are within acceptable levels. Ensure that you are aware of the acceptable range before you accept any values – some projects require a higher level of survey accuracy than others. In any case, the values displayed should never exceed 0.015. 

     The given example (above) is too large a residual. In this case the station height, leveling for both station has to be re-checked!

   Write these numbers into the survey book and Press ‘Set’

   A message “Station and Orientation set!” will be displayed.