TOTAL STATION: THEORY, USES AND APPLICATIONS.

TOTAL STATION: THEORY, USES AND APPLICATIONS.
The total station, (also known as electronic tacheometer) is an instrument that can measure horizontal and vertical angles together with slope distance and can be considered as combined EDM plus electronic theodolite. In common with other electronic surveying equipment, total stations are operated using a multi-function keyboard which is connected to a microprocessor built into the instrument. The microprocessor not only controls both the angle and distance measuring systems but is also used as a small computer that can calculate slope corrections, vertical components, rectangular coordinates and, in some cases, can also store observations directly using an internal memory. Nowadays surveying systems are available which can be use in an integrated manner with Global Positioning System (GPS). so, future total stations may have integrated GPS receivers as part of the measurement unit.

1. BENHA UNIVERSITY
FACULTY OF ENGINEERING, SHOUBRA
GEOMATICS DEPARTMENT

REPORT

TOTAL STATION
THEORY, USES AND APPLICATIONS .



UNDER SUPERVISION OF
ENG. ARWA TEREK

BY
AHMED YASSER AHMED MOHAMED NASSAR

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TABLE OF CONTENTS

1. INTRODUCTION ............................................................................. 2
2. THEORY .......................................................................................... 3
3. USE ................................................................................................ 5
3.1. HOW TO USE TOTAL-STATION (SETTING-UP) ........................... 5
3.2. USES OF TOTAL STATION .......................................................... 7
4. APPLICATIONS ............................................................................... 8



TEAM 3 – SUMMER TRAINING
TEAM MEMBERS NO.
HOSSAM HASSAN RAMADAN HASSAN 1
AHMED FAYEZ MOHAMED AHMED 2
AHMED YASSER AHMED MOHAMED 3
AHMED MOHAMED MESPAH ELSAYED 4
ABD-ELSALAM GAMAL ABD-ELNASSER 5

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1. INTRODUCTION
The total station, (also known as electronic tacheometer) is an
instrument that can measure horizontal and vertical angles together
with slope distance and can be considered as combined EDM plus
electronic theodolite. In common with other electronic surveying
equipment, total stations are operated using a multi-function
keyboard which is connected to a microprocessor built into the
instrument. The microprocessor not only controls both the angle and
distance measuring systems but is also used as a small computer that
can calculate slope corrections, vertical components, rectangular
coordinates and, in some cases, can also store observations directly
using an internal memory. Nowadays surveying systems are available
which can be use in an integrated manner with Global Positioning
System (GPS). so, future total stations may have integrated GPS
receivers as part of the measurement unit.


Figure 1 Evolution of Total Station

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2. THEORY
LIGHT PROPAGATION

??????: velocity of EM energy (meters/sec)
??????: wavelength (meters)
??????: frequency of energy (Hz)

EDM
EDM units employ electromagnetic (EM) energy for measuring the
slope distance to a target point. Two principles are in use: phase shift
and pulse – also called ‘time of flight’ – measurements.
The EM energy may be emitted as infrared carrier signals, generated
by a small solid-state emitter within the instrument’s optical path and
modulated as sine waves.

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The phase of the returning signal is compared to the phase of the
emitted signal. This can be done with a precision at the millimetre
level. However, the total number of full cycles is still unknown and
multiple wavelengths are used to obtain them.
The other method uses laser pulses (time of flight (ToF)). The travel
time of the pulse forth and back (t) is measured and, by multiplying
that by the speed of light (c) and dividing the result by 2, the distance
(d) can be accurately calculated. Some total stations combine both
measurement principles in one and the same instrument. With a
precision ranging from sub-millimetre to sub-centimetre level, the
phase shift method is the most accurate one but its measuring range
is limited to around 100m. ToF EDM units can measure distances of
up to 10km or more, depending on atmospheric conditions and the
type of prism used, but their precision usually ranges from sub-
centimetre to centimetre level while the accuracy deteriorates with
increasingly shorter ranges.

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3. USE
3.1. HOW TO USE TOTAL-STATION (SETTING-UP)
setting up Total Stations above known control points steps are:
1. Locate your desired reference point (survey marker or a hilti-nail or
PK nail) that you will set up above.





2. Extend the legs of the tripod and lock the legs off. Set the tripod
roughly above your reference point and tread the legs into the
ground. The top of the tripod should be roughly chest level (most
comfortable height).





Figure 2 Reference point
Figure 3 Tripod fixation

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3. put the total station on the tripod and lock the centring screw
tightly enough to prevent undue movement of the total station.

4. Look through the laser dot and using the foot screws on the tripod,
adjust them until the cross hairs/laser dot are over reference point.
5. Look at the optical plummet reticle and adjust -two of the three-
legs of the tripod until the bubble is centred and the equipment
plumb. When adjusting the legs of the tripod, wrap your thumb
around the upper part of the leg, above the lower section to
prevents the total station falling over.





Figure 4 Setting the bubble
Figure 5 Optical plummet reticle

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6. Look through the laser dot and check if it is still over the reference
point. If not, then loosen the centring screw and move the total
station and check the circular vial again.
3.2. USES OF TOTAL STATION
It is possible to use total stations to assess topography, measure and
record existing natural features, or buildings planning, highways, and
land boundaries. total stations are also useful in mining, meteorology,
archaeological digs, forensic investigations and building information
modelling (BIM). Total stations are particularly useful for performing
functions such as:
• Topographic surveys
• Land and title surveys
• Roadway and corridor surveys
• Design surveys
• Infrastructure surveys
• Volumetric surveys
• Power line inspections
• Utility design surveys
• Mine and quarry surveys
• Tank calibration or inspection

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4. APPLICATIONS

• Point Location
the coordinates of any sighted point can be determined, displayed,
and recorded in the following format: N.E.Z. (north, east,
elevation). At this time, the sighted point is numbered and coded
for attribute data (point description) all of which is recorded with
the location data. This program is used extensively in topographic
surveys.

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• Trigonometric Leveling
Trigonometric Leveling is the branch of Surveying in which we find out
the vertical distance between two points by taking the vertical angular
observations and the known distances. The known distances are
either assumed to be horizontal or the geodetic lengths at the mean
sea level(MSL).

• Missing Line Measurement
it is the process of finding the distance between two points A & B
(which are not inter-visible from each other) from another point ‘I’
(instrument position). This method is very useful for finding distances
between two points which has an obstruction between them.
It has two types:
Continuous Mode: i.e., AB, BC, CD, DE, EF etc.,

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Radial Mode: i.e., AB, AC, AD, AE, AF etc.,

• Resection
This technique permits the surveyor to set up the total station at any
convenient position (sometimes referred to as a free station) and then
determine the coordinates and elevation of that instrument position
by sighting previously coordinated reference stations. When sighting
only two points of known position, it is necessary to measure and
record both the distances and the angle between the reference
points; when sighting several points (three or more) of known
position, it is necessary only to measure the angles between the
points.

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• Remote Object Elevation
• The surveyor can determine the heights of inaccessible points
(e.g., electricity conductors), while using a total station that is set
up by sighting the (polemounted prism) as it is being held
directly under the object. When the object itself is then sighted,
the object height can be promptly displayed.

• Offset Measurements
• Layout or Setting-Out Positions
• Area Computation
• Azimuth Determination