MINISTRY OF EDUCATION
STATE DEPARTMENT OF VOCATIONAL & TECHNICAL TRAINING
NYAMIRA NATIONAL POLYTECHNIC
P.O BOX 382 – 40500 NYAMIRA TEL: 0794519220
Website: www.ekerubogietai.ac.ke
Email:
Republic of Kenya
Traverse surveying February 2023
Specific objectives
By the end of this course unit the trainee should be able to:
a. Define the term traverse
b. Classify traverses into orders, types and forms of instrumentation
c. Explain the construction of traverse signals
d. Describe the field procedure for traversing
e. State the procedure of booking of traverse observations in the field
f. Explain how to carry out computations and adjustments of traverses
Traverse
A traverse is a series of consecutive lines connecting points on the earth’s surface whose
bearings and distances have been observed for the purpose of determining the positions
of the points.
In traversing, the initial observation is made to a reference direction (meridian) and
angles (directions) and distances are observed at each station.
The forward station (B) is fixed from the instrument station (A) and in the next stage,
the stage B becomes the instrument station to fix a new forward station(C). Thus a
traverse follows a zigzag course as shown above (figure 2)
θ2
θ3
θ1
Figure 1 Traverse
Classification of traverses
Traverses may be classified according to the following criteria
1. According to accuracy
2. According to ground configuration – according to type
3. According to form of instrumentation
According to order of accuracy
The determining factor here is the accuracy of the end result. The categories are 1st order, 2nd
order, 3rd order etc.
1st order (precise or geodetic traverse)
This is the highest ranked traverse in the accuracy classification and is intended to
replace/substitute 1st and 2nd order triangulation
NYAMIRA NATIONAL POLYTECHNIC
Traverse surveying by Henry Oginga Page 1 of 27
, Angles are measured with utmost accuracy in several rounds on different zeros using a
geodetic theodolite reading to 0.1’’ each observation being the mean of both faces of the
instrument.
Distances will normally be measured by EDM (electromagnetic distance meter) or an
invar tape.
The tape is standardized and all tape corrections made to the measured distances with
tension applied by weights or straining trestles.
For long traverses, astronomical observations are made at about every 10th station
The order of accuracy is about 1: 100 000.
In Kenya these are done by government agencies under the Direction of the Director of
Surveys
nd
2 order traverse
The observation conditions are generally about the same as 1st order but of lower rigour.
They are carried out to densify the control in the gaps left by 1st order traverses.
The order of accuracy is about 1:50 000 – 1: 100 000
rd
3 order (tertiary) traverse
This type of traverse is used in locating detail and setting out engineering structures
Angular measurements are made with micrometer theodolite reading to 1’’ and distances
measured with a steel tape with standard tape correction applied.
All such lines shall be double-chained, and
Field operations shall be appropriate to a standard of accuracy of not less than 1:20,000.
Classification based on form/configuration/type
This classification depends on the ground configuration of the traverse legs on the ground. The
types are:
1. Open traverse
2. Closed loop traverse
3. Closed link traverse
Open traverse
This type of traverse starts at a known station and but does not close at any known
station.
It is also known as a hanging or swinging traverse
The great disadvantage of this type is that there is no way of checking on closure or
adjustment thus any gross errors will pass undetected.
It is seldom used except for preliminary surveys for linear projects e.g. roads, railways,
transmission lines, canals etc.
It is also frequently utilized in mining and tunneling work because of the physical
restriction on closure.
NYAMIRA NATIONAL POLYTECHNIC
Traverse surveying by Henry Oginga Page 2 of 27
, θ2
θ3
θ1
Figure2 Open traverse
Closed loop traverse
This is a traverse that starts and closes on the same
station, whose position may be known or unknown
It may or may not have outside orientation or may be
referred to an arbitrary meridian
Angular and coordinate closure may be checked and
adjusted and cross referencing between the points is
possible if visibility allows
Figure 3 loop traverse
Closed link traverse
This type of traverse commences and closes at known points with opening and closing
orientation
It is a superior traverse and most widely used and can readily be checked for closure
/errors and adjusted
Closed traverses provide checks on the observed angles and distances, which is an
extremely important consideration. They are used extensively in control, construction,
property, and topographic surveys
NYAMIRA NATIONAL POLYTECHNIC
Traverse surveying by Henry Oginga Page 3 of 27
STATE DEPARTMENT OF VOCATIONAL & TECHNICAL TRAINING
NYAMIRA NATIONAL POLYTECHNIC
P.O BOX 382 – 40500 NYAMIRA TEL: 0794519220
Website: www.ekerubogietai.ac.ke
Email:
Republic of Kenya
Traverse surveying February 2023
Specific objectives
By the end of this course unit the trainee should be able to:
a. Define the term traverse
b. Classify traverses into orders, types and forms of instrumentation
c. Explain the construction of traverse signals
d. Describe the field procedure for traversing
e. State the procedure of booking of traverse observations in the field
f. Explain how to carry out computations and adjustments of traverses
Traverse
A traverse is a series of consecutive lines connecting points on the earth’s surface whose
bearings and distances have been observed for the purpose of determining the positions
of the points.
In traversing, the initial observation is made to a reference direction (meridian) and
angles (directions) and distances are observed at each station.
The forward station (B) is fixed from the instrument station (A) and in the next stage,
the stage B becomes the instrument station to fix a new forward station(C). Thus a
traverse follows a zigzag course as shown above (figure 2)
θ2
θ3
θ1
Figure 1 Traverse
Classification of traverses
Traverses may be classified according to the following criteria
1. According to accuracy
2. According to ground configuration – according to type
3. According to form of instrumentation
According to order of accuracy
The determining factor here is the accuracy of the end result. The categories are 1st order, 2nd
order, 3rd order etc.
1st order (precise or geodetic traverse)
This is the highest ranked traverse in the accuracy classification and is intended to
replace/substitute 1st and 2nd order triangulation
NYAMIRA NATIONAL POLYTECHNIC
Traverse surveying by Henry Oginga Page 1 of 27
, Angles are measured with utmost accuracy in several rounds on different zeros using a
geodetic theodolite reading to 0.1’’ each observation being the mean of both faces of the
instrument.
Distances will normally be measured by EDM (electromagnetic distance meter) or an
invar tape.
The tape is standardized and all tape corrections made to the measured distances with
tension applied by weights or straining trestles.
For long traverses, astronomical observations are made at about every 10th station
The order of accuracy is about 1: 100 000.
In Kenya these are done by government agencies under the Direction of the Director of
Surveys
nd
2 order traverse
The observation conditions are generally about the same as 1st order but of lower rigour.
They are carried out to densify the control in the gaps left by 1st order traverses.
The order of accuracy is about 1:50 000 – 1: 100 000
rd
3 order (tertiary) traverse
This type of traverse is used in locating detail and setting out engineering structures
Angular measurements are made with micrometer theodolite reading to 1’’ and distances
measured with a steel tape with standard tape correction applied.
All such lines shall be double-chained, and
Field operations shall be appropriate to a standard of accuracy of not less than 1:20,000.
Classification based on form/configuration/type
This classification depends on the ground configuration of the traverse legs on the ground. The
types are:
1. Open traverse
2. Closed loop traverse
3. Closed link traverse
Open traverse
This type of traverse starts at a known station and but does not close at any known
station.
It is also known as a hanging or swinging traverse
The great disadvantage of this type is that there is no way of checking on closure or
adjustment thus any gross errors will pass undetected.
It is seldom used except for preliminary surveys for linear projects e.g. roads, railways,
transmission lines, canals etc.
It is also frequently utilized in mining and tunneling work because of the physical
restriction on closure.
NYAMIRA NATIONAL POLYTECHNIC
Traverse surveying by Henry Oginga Page 2 of 27
, θ2
θ3
θ1
Figure2 Open traverse
Closed loop traverse
This is a traverse that starts and closes on the same
station, whose position may be known or unknown
It may or may not have outside orientation or may be
referred to an arbitrary meridian
Angular and coordinate closure may be checked and
adjusted and cross referencing between the points is
possible if visibility allows
Figure 3 loop traverse
Closed link traverse
This type of traverse commences and closes at known points with opening and closing
orientation
It is a superior traverse and most widely used and can readily be checked for closure
/errors and adjusted
Closed traverses provide checks on the observed angles and distances, which is an
extremely important consideration. They are used extensively in control, construction,
property, and topographic surveys
NYAMIRA NATIONAL POLYTECHNIC
Traverse surveying by Henry Oginga Page 3 of 27
