Total Station Survey

Introduction

For this exercise we would be learning how to use a TOPCON Total Station.  These are commonly seen being used by highway workers.  They are used to gather elevation data of an area from a fixed point to create a topographic map.  The total station works by sending a laser from the station out to a prism on top of a pole.  This bounces the laser back to the station, where it records the distance between the two as well as the change in elevation between them. 

The TOPCON Total Station, ready for use.

Study Area

The study area we chose is the UWEC campus mall, at the site of the original Davies Center student building.  That building was torn down in recent years and replaced with a large open green lawn crisscrossed with cement walking paths.  It is bordered on its wide sides by a brook and a series of planters in front of the library.  It is bounded on its long sides by the edge of the library and the social sciences building. 

 The main view of our study area, facing the library.

Methods

The procedure is, the total station stays put.  It has a tripod that is mounted into the ground to hold it steady.  Once this is done, the device is calibrated.  Similar to a microscope, it has a rough adjustment knob and fine adjustment knobs.  The purpose of the calibration is to get the device level with the ground.  The rough adjustment gets it roughly in place, and then there are three fine adjustment knobs, one for each leg of the tripod, that need to be dialed into place.  A bevel is above each leg and the bubble in the bevel needs to be centered.  When this is done, the device is ready to use.

There are two additional pieces of equipment that are used to do the survey: the remote, that is used to capture the data, and the pole, which has a prism mounted on top of it.  To do the survey, the pole is walked out to a point in the mappable area and held steady, level with the ground.  The pole has a bevel as well, which makes this simple.  At the same time, a person at the Total Station looks through the viewfinder window and points its crosshairs at the mirror atop the pole.  When this is positioned correctly, he indicates for the person holding the remote to capture a point.  The remote is linked to the Total Station via Bluetooth.  Capturing a point in as simple as pushing a button on the touchscreen of the remote.  After it says that the point has been captured, hyou are ready to move the pole, re-aim the total station, and capture another point. 

Using the Total Station.  Jeremy, pictured in the right, is handling the remote.  Circled in red is the member of our group holding upright the pole.

Points should be taken a reasonable distance from one another.  Obviously, the closer that they are taken, the more precise the resulting survey will be.  For our exercise we took points that were roughly five to ten feet apart.  This generated a reasonable surface for our study area.  With this data in hand, it is easy to import into Arc to generate a elevation surface model.  

The finished Total Station survey, created by group member Travis Haas.