ISO 17123-5:2018

INTERNATIONAL ISO
STANDARD 17123-5
Third edition
2018-02
Optics and optical instruments —
Field procedures for testing geodetic
and surveying instruments —
Part 5:
Total stations
Optique et instruments d'optique — Méthodes d'essai sur site des
instruments géodésiques et d'observation —
Partie 5: Stations totales
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and subscripts . 2
4.1 Symbols . 2
4.2 Subscripts . 2
5 General . 3
5.1 Requirements . 3
5.2 Procedure 1: Simplified test procedure . 4
5.3 Procedure 2: Full test procedure . 4
6 Simplified test procedure . 5
6.1 Configuration of the test field. 5
6.2 Measurement . 5
6.3 Calculation . 6
6.3.1 x-, y-coordinates . 6
6.3.2 z-coordinate . 7
6.3.3 Evaluation . 7
7 Full test procedure . 7
7.1 Configuration of the test field. 7
7.2 Measurement . 8
7.3 Calculation . 8
7.3.1 x-, y-coordinates . 8
7.3.2 z-coordinate .12
7.4 Statistical tests .12
7.4.1 General.12
7.4.2 Response to Question a) .13
7.4.3 Response to question b) .14
7.5 Combined uncertainty evaluation (Type A and Type B) .14
Annex A (informative) Example of a simplified test procedure .16
Annex B (informative) Example of the full test procedure .18
Annex C (informative) Example of the calculation of a combined uncertainty budget (Type
A and Type B) .24
Annex D (informative) Sources which are not included in uncertainty evaluation.27
Bibliography .28
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee
SC 6, Geodetic and surveying instruments.
This third edition cancels and replaces the second edition (ISO 17123-5:2012), which has been
technically revised.
A list of all parts in the ISO 17123 series can be found on the ISO website.
iv © ISO 2018 – All rights reserved

Introduction
This document specifies field procedures for adoption when determining and evaluating the uncertainty
of measurement results obtained by geodetic instruments and their ancillary equipment, when used in
building and surveying measuring tasks. Primarily, these tests are intended to be field verifications
of suitability of a particular instrument for the immediate task. They are not proposed as tests for
acceptance or performance evaluations that are more comprehensive in nature.
The definition and concept of uncertainty as a quantitative attribute to the final result of measurement
was developed mainly in the last two decades, even though error analysis has already long been a part of
all measurement sciences. After several stages, the CIPM (Comité Internationale des Poids et Mesures)
referred the task of developing a detailed guide to ISO. Under the responsibility of the ISO Technical
Advisory Group on Metrology (TAG 4), and in conjunction with six worldwide metrology organizations,
a guidance document on the expression of measurement uncertainty was compiled with the objective
of providing rules for use within standardization, calibration, laboratory, accreditation and metrology
services. ISO/IEC Guide 98–3 was first published in 1995.
With the introduction of uncertainty in measurement in ISO 17123 (all parts), it is intended to finally
provide a uniform, quantitative expression of measurement uncertainty in geodetic metrology with the
aim of meeting the requirements of customers.
ISO 17123 (all parts) provides not only a means of evaluating the precision (experimental standard
deviation) of an instrument, but also a tool for defining an uncertainty budget, which allows for the
summation of all uncertainty components, whether they are random or systematic, to a representative
measure of accuracy, i.e. the combined standard uncertainty.
ISO 17123 (all parts) therefore provides, for defining for each instrument investigated by the procedures,
a proposal for additional, typical influence quantities, which can be expected during practical use. The
customer can estimate, for a specific application, the relevant standard uncertainty components in
order to derive and state the uncertainty of the measuring result.
INTERNATIONAL STANDARD ISO 17123-5:2018(E)
Optics and optical instruments — Field procedures for
testing geodetic and surveying instruments —
Part 5:
Total stations
1 Scope
This document specifies field procedures to be adopted when determining and evaluating the precision
(repeatability) of coordinate measurement of total stations and their ancillary equipment when used
in building and surveying measurements. Primarily, these tests are intended to be field verifications of
the suitability of a particular instrument for the immediate task at hand and to satisfy the requirements
of other standards. They are not proposed as tests for acceptance or performance evaluations that are
more comprehensive in nature.
These field procedures have been developed specifically for in situ applications without the need for
special ancillary equipment and are purposely designed to minimize atmospheric influences.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3534-1, Statistics — Vocabulary and symbols — Part 1: General statistical terms and terms used in
probability
ISO 4463-1, Measurement methods for building — Setting-out and measurement — Part 1: Planning and
organization, measuring procedures, acceptance criteria
ISO 7077, Measuring methods for building — General principles and procedures for the verification of
dimensional compliance
ISO 7078, Building construction — Procedures for setting out, measurement and surveying — Vocabulary
and guidance notes
ISO 9849, Optics and optical instruments — Geodetic and surveying instruments — Vocabulary
ISO 17123-1, Optics and optical instruments — Field procedures for testing geodetic and surveying
instruments — Part 1: Theory
ISO 17123-3, Optics and optical instruments — Field procedures for testing geodetic and surveying
instruments — Part 3: Theodolites
ISO 17123-4, Optics and optical instruments — Field procedures for testing geodetic and surveying
instruments — Part 4: Electro-optical distance meters (EDM measurements to reflectors)
ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM: 1995)
ISO/IEC Guide 99:2007, International vocabulary of metrology — Basic and general concepts and
associated terms (VIM)
3 Terms and definitions
For the purposes of this document, the terms and definition given in ISO 3534-1, ISO 4463-1, ISO 7077,
ISO 7078, ISO 9849, ISO 17123-1, ISO/IEC Guide 98-3 (GUM) and ISO/IEC Guide 99 (VIM) apply.
4 Symbols and subscripts
4.1 Symbols
Symbol Quantity Unit
a mean value of height differences m
d deviation, differences m
k coverage factor —
L mean value of horizontal distance between two m
target points
l horizontal distance between two target points m
M vertex of the triangle of the mathematical model —
p parameter to calculate the rotation angle —
q parameter to calculate the rotation angle —
r difference to the mean value m
S instrument station —
s experimental standard deviation various
experimental standard deviation of the same various

s
population
T target point —
U expanded uncertainty various
u uncertainty various
v degree of freedom —
X mathematical model coordinate X m
x measured coordinate x m
Y mathematical model coordinate Y m
y measured coordinate y m
Z mathematical model coordinate Z m
z measured coordinate z m
α confidence level —
σ standard deviation of a population various
standard deviation of the same population various

σ
θ horizontal rotation angle °
Ψ Vertical (elevation) angle °
χ Chi-Quadrat distribution —
4.2 Subscripts
Subscript Term
0,975 confidence level 0,975
1-α confidence level
dist distance
disp minimum display digit of coordinates
2 © ISO 2018 – All rights reserved

Subscript Term
dispx minimum display digit of coordinate x
dispy minimum display digit of coordinate y
dispz minimum display digit of coordinate z
E east axis
g centre of gravity
H height axis
hs height stability of tripod
i instrument station No.
ISO-TS total station according to ISO 17123-5
ISO-TS-XY coordinates XY measured once in both
face positions of the telescope according to
ISO 17123-5
ISO-TS-Z coordinates Z measured once in both face
positions of the telescope according to
ISO 17123-5
j target point No.
k measured set number (single telescope face)
m coordinate of the centre of gravity of the
mathematical model after rotation
N north axis
prs pressure
rh relative humidity
dist-TS distance measurement in total station
θ-TS horizontal angle on specification of total
station
t coordinate of the centre of gravity of the
mathematical model after the shift
temp temperature
trd tripod torsion
θ horizontal angle
Ψ vertical angle or elevation angle
Ψ-TS vertical angle on specification of total station
x coordinate x (up)
xy coordinates xy (horizontal)
XY coordinates XY (horizontal) of the
mathematical model
y coordinate y (right)
Z coordinate Z (height) of the mathematical
model
z coordinate z (height)
5 General
5.1 Requirements
Before commencing the measurements, it is important that the operator ensures that the precision in
use of the measuring equipment is appropriate for the intended measuring task.
The total station and its ancillary equipment shall be in known and acceptable states of permanent
adjustment according to the methods specified in the manufacturer’s reference manual, and used
tripods with reflectors as recommended by the manufacturer.
The coordinates are considered as observables because on modern total stations they are selectable as
output quantities.
All coordinates shall be measured on the same day. The instrument should always be levelled carefully.
The correct zero-point correction of the reflector prism shall be used.
The results of these tests are influenced by meteorological conditions, especially by the gradient of
temperature. An overcast sky and low wind speed guarantee the most favourable weather conditions.
Actual meteorological data shall be measured in order to derive atmospheric corrections, which shall
be added to the raw distances. The particular conditions to be taken into account can vary depending
on where the tasks are to be undertaken. These conditions shall include variations in air temperature,
wind speed, cloud cover and visibility. Note should also be taken of the actual weather conditions at the
time of measurement and the type of surface above which the measurements are made. The conditions
chosen for the tests should match those expected when the intended measuring task is actually carried
out (see ISO 7077 and ISO 7078).
Tests performed in laboratories would provide results which are almost unaffected by atmospheric
influences, but the costs for such tests are very high, and therefore they are not practicable for most
users. In addition, laboratory tests yield precisions much higher than those that can be obtained under
field conditions.
This document describes two different field procedures as given in Clauses 6 and 7. The operator shall
choose the procedure which is most relevant to the project's particular requirements.
To evaluate angle measurement and distance measurement separately, ISO 17123-3 and ISO 17123-4
shall be applied accordingly.
5.2 Procedure 1: Simplified test procedure
The simplified test procedure provides an estimate as to whether the precision of a given total station
is within the specified permitted deviation in accordance with ISO 4463-1.
The simplified test procedure is based on a limited number of measurements. This test procedure
relies on measurements of x-, y- and z-coordinates in a test field without nominal values. The maximum
difference from mean value is calculated as an indicator for the precision.
A significant standard deviation cannot be obtained. If a more precise assessment of the total station
under field conditions is required, it is recommended to adopt the more rigorous full test procedure as
given in Clause 7.
An example of the simplified test procedure is given in Annex A.
5.3 Procedure 2: Full test procedure
The full test procedure shall be adopted to determine the best achievable measure of precision of a
total station and its ancillary equipment under field conditions.
This procedure is based on measurements of coordinates in a test field without nominal values. The
experimental standard deviation of the coordinate measurement of a single point is determined from
least squares adjustments.
The full test procedure given in Clause 7 of this document is intended for determining the measure of
precision in use of a particular total station. This measure of precision in use is expressed in terms of
the experimental standard deviations s and s of a coordinate measured once in both face
ISO-TS-XY ISO-TS-Z
positions of the telescope.
4 © ISO 2018 – All rights reserved

Furthermore, this procedure can be used to determine:
— the measure of precision in use of total stations by a single survey team with a single instrument
and its ancillary equipment at a given time;
— the measure of precision in use of a single instrument over time;
— the measure of precision in use of each of several total stations in order to enable a comparison of
their respective achievable precisions to be obtained under similar field conditions.
Statistical tests should be applied to determine whether the experimental standard deviations obtained
belong to the population of the instrumentation's theoretical standard deviations and whether two
tested samples belong to the same population.
An example of the full test procedure is given in Annex B.
6 Simplified test procedure
6.1 Configuration of the test field
Two target points (T , T ) shall be set out as indicated in Figure 1. The targets should be firmly fixed on
1 2
to the ground. The distance between two target points should be set longer than the average distance
(e.g. 60 m) according to the intended measuring task. Their heights should be as different as the surface
of the ground allows.
Two instrument stations (S , S ) shall be set out approximately in line with two target points. S shall
1 2 1
be set 5 m to 10 m away from T and in the opposite direction to T . S shall be set between two target
1 2 2
points and 5 m to 10 m away from T .
Figure 1 — Configuration of the test field
6.2 Measurement
One set consists of two measurements to each target point in one telescope face at one of the instrument
stations.
The coordinates of the two target points shall be measured by 4 sets (telescope face: I – II – I – II) at the
instrument station S . The instrument is shifted to station S and the same sequence of measurements is
1 2
carried out. Station coordinates and the reference orientation of the station are discretionary in each set.
On-board or stand-alone software shall be used for the observations. It is preferable to use the same
software which will be used for the practical work.
The sequence of the measurements is shown in Table 1.
Table 1 — Sequence of the measurements for one series
Seq. No. Instrument Target Set Telescope x y z
station point face
k
i j
1 1 x y z
1,1,1 1,1,1 1,1,1
1 I
2 2 x y z
1,2,1 1,2,1 1,2,1
3 1 x y z
1,1,2 1,1,2 1,1,2
2 II
4 2 x y z
1,2,2 1,2,2 1,2,2
5 1 x y z
1,1,3 1,1,3 1,1,3
3 I
6 2 x y z
1,2,3 1,2,3 1,2,3
7 1 x y z
1,1,4 1,1,4 1,1,4
4 II
8 2 x y z
1,2,4 1,2,4 1,2,4
9 2 1 1 I x y z
2,1,1 2,1,1 2,1,1
       
15 1 x y z
2,1,4 2,1,4 2,1,4
2 4 II
16 2 x y z
2,2,4 2,2,4 2,2,4
6.3 Calculation
6.3.1 x-, y-coordinates
The evaluation of the test results is given by the deviation of the horizontal distance of each set from
the mean value of all measured horizontal distances.
Each horizontal distance between two target points l is calculated as:
i,k
2 2
lx=−xy+− y  i = 1, 2; k = 1, 2, 3, 4 (1)
() ()
ik,,ik21,,ik,,ik21,,ik,
Their mean value L is calculated as:
2 4
Ll= (2)
ik,
∑∑
i=1k=1
The values of the deviation of each distance from its mean r is calculated as:
i,k
rl=−L  i = 1, 2; k = 1, 2, 3, 4 (3)
ik,,ik
The maximum value d of the r is defined as:
xy i,k
dr=max  i = 1, 2; k = 1, 2, 3, 4 (4)
xy ik,
6 © ISO 2018 – All rights reserved

6.3.2 z-coordinate
The height differences d between target points are calculated using measured z-coordinate values
z,i,k
in each set:
dz=−z  i = 1, 2; k = 1, 2, 3, 4 (5)
z,ik,,ik21,,ik,
The mean value a of height difference in all sets:
z
2 4
ad= (6)
zz∑∑ ,ik,
i=1k=1
The differences r between height differences of two target points and the mean value a :
z,i,k z
rd=−a  i = 1, 2; k = 1, 2, 3, 4 (7)
z,ik,,z,ik z
The maximum difference value d is calculated as:
z
dr=max (8)
zz,ik,
6.3.3 Evaluation
The differences d and d shall be within the specified permitted deviation, p and p respectively, (in
xy z xy z
accordance with ISO 4463-1 for the intended measuring task). If p and p are not given, they shall be
xy z
ds≤×25, 2× and ds≤×25, 2× respectively, where s and s are the
ISO-TS-XY ISO-TS-Z
xy ISO-TS-XY zISO-TS-Z
experimental standard deviations of the x-, y- and z-measurements respectively, determined according
to the full test procedure with the same instrument.
7 Full test procedure
7.1 Configuration of the test field
Three target points (T , T , T ) shall be set out at the corner of the triangle (see Figure 2). The targets
1 2 3
should be firmly fixed on to the ground. The distances of target p
...