ISO 19116:2004

Geographic information - Positioning services

ISO 19116:2004 specifies the data structure and content of an interface that permits communication between position-providing device(s) and position-using device(s) so that the position-using device(s) can obtain and unambiguously interpret position information and determine whether the results meet the requirements of the use. A standardized interface of geographic information with position allows the integration of positional information from a variety of positioning technologies into a variety of geographic information applications, such as surveying, navigation and intelligent transportation systems. ISO 19116:2004 will benefit a wide range of applications for which positional information is important.

Information géographique — Services de positionnement

Geografske informacije – Lokacijske storitve

General Information

• Status: Withdrawn
• Publication Date: 23-Jun-2004
• Withdrawal Date: 23-Jun-2004
• ICS: 35.240.70 - IT applications in science
• Technical Committee: ISO/TC 211 - Geographic information/Geomatics
• Drafting Committee: ISO/TC 211/WG 4 - Geospatial services
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 02-Dec-2019
• Completion Date: 13-Dec-2025
• Ref Project: SIST ISO 19116:2004 - Geographic information -- Positioning services

Relations

• Revised: ISO 19116:2019 - Geographic information - Positioning services
• Effective Date: 27-Feb-2016

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 19116
First edition
2004-07-01
Geographic information — Positioning
services
Information géographique — Services de positionnement

Reference number
©
ISO 2004
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ii © ISO 2004 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Conformance . 1
3 Normative references . 1
4 Terms and definitions. 2
5 Symbols, abbreviations and UML notations . 6
5.1 Symbols and abbreviated terms. 6
5.2 UML Notations. 7
5.3 UML model stereotypes. 7
5.4 Package abbreviations . 8
6 Positioning services model . 8
6.1 Introduction . 8
6.2 Static data structures of positioning services classes. 9
6.3 Positioning services operations. 10
6.4 Basic and Extended Information . 13
7 Basic information definition and description. 14
7.1 Introduction . 14
7.2 System Information. 15
7.3 Session. 19
7.4 Mode of operation . 20
7.5 Quality information . 35
8 Technology-specific information . 38
8.1 Introduction . 38
8.2 GNSS Operating Conditions . 38
8.3 Raw measurement data. 43
Annex A (normative) Conformance . 44
Annex B (informative) Implementing accuracy reports for positioning services. 47
Bibliography . 51

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 19116 was prepared by Technical Committee ISO/TC 211, Geographic information/Geomatics.
iv © ISO 2004 – All rights reserved

Introduction
0.1 General
Positioning services are among the processing services identified in ISO 19119. Processing services include
services that are computationally oriented and operate upon the elements from the model domain, rather than
being directly integrated in the model domain itself. This International Standard defines and describes the
positioning service. Other services in this domain are coordinate transformation, metric translation, format
conversion, semantic translation, etc.
Positioning services employ a wide variety of technologies that provide position and related information to a
similarly wide variety of applications, as depicted in Figure 1. Although these technologies differ in many
respects, there are important items of information that are common among them and serve common needs of
these application areas, such as the position data, time of observation and its accuracy. Also, there are items
of information that apply only to specific technologies and are sometimes required in order to make correct
use of the positioning results, such as signal strength, geometry factors, and raw measurements. Therefore,
this International Standard includes both general data elements that are applicable to a wide variety of
positioning services and technology specific elements that are relevant to particular technologies.

Figure 1 — Positioning services interface allows communication of position data for a wide variety of
positioning technologies and users
Modern electronic positioning technology can measure the coordinates of a location on or near the Earth with
great speed and accuracy, thereby allowing geographic information systems to be populated with any number
of objects. However, the technologies for position determination have had neither a common structure for
expression of position information, nor a common structure for expression of accuracy. The positioning-
services interface specified in this International Standard provides data structures and operations that allow
spatially oriented systems, such as GIS, to employ these technologies with greater efficiency by permitting
interoperability among various implementations and various technologies.
This interface may be applied to communication among any of the components of systems that generate and
use position information. Such systems may incorporate an instrument providing position updates to one or
more position-using devices for data processing, storage, and display. For example, a navigation display
system may include recording functions that store the history of a vehicle’s movement, processing tools that
compute guidance updates along a planned course relying on stored waypoints, and a display device that
provides the navigator with current position, computed guidance information, and cartography from stored
coordinate information. This International Standard specifies an interface that carries position and related
information among any of these components, and should be sufficient for communication between the position
providing device and any connected position using devices. Additional interfaces may also exist in such a
system, for example providing for cartographic portrayal of stored coordinate information, which are outside
the scope of this International Standard.
Standard positioning services provide client systems with operations that access positioning results and
related information in a uniform manner, isolating the client from the multiplicity of protocols that may be
employed to communicate with the positioning instruments. For example, a realized-positioning service could
communicate with a GNSS receiver using the well-known NMEA 0183 protocol, translate the information, and
provide the positioning results to a geographic information display client through the ISO 19116 standard
interface specified in this document. Another realized-positioning service could communicate with a GNSS
receiver using a manufacturer's proprietary binary protocol. Through the use of standardized positioning
service interfaces, the hardware communication protocols become transparent to the client application.
Evolution of new communication protocols that closely follow the data structures described in this International
Standard is also anticipated. Such communication standards will facilitate efficient fulfilment of the information
requirements of the positioning services interface and facilitate modular interchangeability of the positioning
technology components.
0.2 Potential use of the service
The application of this International Standard is illustrated in Figure 2 by a simplified case for a user obtaining
coordinates from a GNSS receiver.

Figure 2 — Use case for getting coordinates from a positioning service
vi © ISO 2004 – All rights reserved

First, the positioning service device transmits system-identification data so that the user can determine the
type of positioning system, in this case a GNSS receiver, and whether the system is operational.
Next, the user sets the GNSS receiver to provide coordinates in the desired Coordinate Reference System
(CRS) through the interface by performing setMode operations. For instance, the coordinate reference system
could be set to NAD27 Virginia State Plane, North Zone, US Survey feet. Note that by using well-recognized
CRS names in accordance with the ISO 19111 structure, the user avoids some of the complexity of the
definition of the coordinate reference system by using a named datum and mapping projection, and the
system interprets these and loads predefined set of parameters.
By performing technology-specific setOperatingConditions operations, the user also sets certain operating
conditions of the system so that the position determination will be performed in a desired manner. For
example, the user sets the satellite-elevation mask of the GNSS receiver so that satellites that are at low
angles in the sky, and consequently, more affected by signal passage through the atmosphere, are excluded
from the computation. Certain other operating conditions, such as the current actual positions of available
satellites, are not controllable by the user and are determined by the system.
The system then performs measurements according to the operating conditions of the signal from the GNSS
satellites and uses these measurements to compute a position cast in the specified Coordinate Reference
System.
Finally, the computed position is reported to the user through the PS_Observation data object.
The positioning system also reports on certain operating conditions to help the user decide whether to use the
position value. For example, one of the indicators of solution quality is the dilution of precision (DOP) value,
which is based on the geometry of the satellites observed to determine the position.
Communication of this information is performed through the standard data structures to the user’s display
device, which portrays it to the user.

INTERNATIONAL STANDARD ISO 19116:2004(E)

Geographic information — Positioning services
1 Scope
This International Standard specifies the data structure and content of an interface that permits
communication between position-providing device(s) and position-using device(s) so that the position-using
device(s) can obtain and unambiguously interpret position information and determine whether the results meet
the requirements of the use. A standardized interface of geographic information with position allows the
integration of positional information from a variety of positioning technologies into a variety of geographic
information applications, such as surveying, navigation and intelligent transportation systems. This
International Standard will benefit a wide range of applications for which positional information is important.
2 Conformance
This International Standard defines two levels of conformance: Basic (that all implementations shall meet) and
Extended (for technology-specific data related to a positioning system). Any positioning services
implementation or product claiming conformance with this part of the International Standard shall pass all the
requirements described in the corresponding abstract test suite set forth in Annex A.
3 Normative references
The following referenced documents are indispensable for the application 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 1000:1992, SI units and recommendations for the use of their multiples and of certain other units
1)
ISO/TS 19103:— , Geographic information — Conceptual schema language
ISO 19108:2002, Geographic information — Temporal schema
ISO 19111:2003, Geographic information — Spatial referencing by coordinates
ISO 19113:2002, Geographic information — Quality principles
ISO 19114:2003, Geographic information — Quality evaluation procedures
ISO 19115:2003, Geographic information — Metadata

1) To be published.
4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
accuracy
closeness of agreement between a test result and the accepted reference value
[ISO 3534-1]
NOTE For positioning services, the test result is a measured value or set of values.
4.2
attitude
orientation of a body, described by the angles between the axes of that body’s coordinate system (4.5) and
the axes of an external coordinate system (4.5)
NOTE In positioning services, this is usually the orientation of the user’s platform, such as an aircraft, boat, or
automobile.
4.3
coordinate
one of a sequence of n numbers designating the position of a point in n-dimensional space
[ISO 19111]
NOTE In a coordinate reference system, the numbers must be qualified by units.
4.4
coordinate reference system
coordinate system (4.5) that is related to the real world by a datum (4.6)
[ISO 19111]
NOTE For geodetic and vertical datums, it will be related to the Earth.
4.5
coordinate system
set of mathematical rules for specifying how coordinates (4.3) are to be assigned to points
[ISO 19111]
4.6
datum
parameter or set of parameters that serve as a reference or basis for the calculation of other parameters
[ISO 19111]
NOTE 1 A datum defines the position of the origin, the scale, and the orientation of the axes of a coordinate system.
NOTE 2 A datum may be a geodetic datum, a vertical datum or an engineering datum.
4.7
ellipsoidal height
geodetic height
h
distance of a point from the ellipsoid measured along the perpendicular from the ellipsoid to this point, positive
if upwards or outside of the ellipsoid
[ISO 19111]
NOTE Only used as part of a three-dimensional geodetic coordinate system and never on its own.
2 © ISO 2004 – All rights reserved

4.8
geodetic datum
datum (4.6) describing the relationship of a coordinate system (4.5) to the Earth
[ISO 19111]
NOTE In most cases, the geodetic datum includes an ellipsoid definition.
4.9
gravity-related height
H
height (4.10) dependent on the Earth’s gravity field
[ISO 19111]
NOTE In particular, orthometric height or normal height, which are both approximations of the distance of a point
above the mean sea level.
4.10
height
altitude
h
H
distance of a point from a chosen reference surface along a line perpendicular to that surface
[ISO 19111]
NOTE 1 See ellipsoidal height and gravity-related height.
NOTE 2 Height of a point outside the surface treated as positive; negative height is designated as depth.
4.11
inertial positioning system
positioning system (4.21) employing accelerometers, gyroscopes, and computers as integral components to
determine coordinates (4.3) of points or objects relative to an initial known reference point
4.12
integrated positioning system
positioning system (4.21) incorporating two or more positioning technologies
NOTE The measurements produced by each positioning technology in an integrated system may be of any position,
motion, or attitude. There may be redundant measurements. When combined, a unified position, motion, or attitude is
determined.
4.13
linear positioning system
positioning system (4.21) that measures distance from a reference point along a route
EXAMPLE An odometer used in conjunction with predefined mile or kilometre origin points along a route and
provides a linear reference to a position.
4.14
linear reference system
reference system that identifies a location by reference to a segment of a linear geographic feature and
distance along that segment from a given point
NOTE Linear reference systems are widely used in transportation, for example highway names and mile or kilometre
markers.
4.15
map projection
coordinate (4.3) conversion from a geodetic coordinate system (4.5) to a plane
[ISO 19111]
4.16
motion
change in the position of an object over time, represented by change of coordinate (4.3) values with respect
to a particular reference frame
EXAMPLE This may be motion of the position sensor mounted on a vehicle or other platform or motion of an object
being tracked by a positioning system.
4.17
operating conditions
parameters influencing the determination of coordinate (4.3) values by a positioning system (4.21)
NOTE Measurements acquired in the field are affected by many instrumental and environmental factors, including
meteorological conditions, computational methods and constraints, imperfect instrument construction, incomplete
instrument adjustment or calibration, and, in the case of optical measuring systems, the personal bias of the observer.
Solutions for positions may be affected by the geometric relationships of the observed data and/or mathematical model
employed in the processing software.
4.18
optical positioning system
positioning system (4.21) that determines the position of an object by means of the properties of light
EXAMPLE Total Station: Commonly used term for an integrated optical positioning system incorporating an
electronic theodolite and an electronic distance-measuring instrument into a single unit with an internal microprocessor for
automatic computations.
4.19
performance indicator
internal parameters of positioning systems (4.21) indicative of the level of performance achieved
NOTE Performance indicators can be used as quality-control evidence of the positioning system and/or positioning
solution. Internal quality control may include such factors as signal strength of received radio signals [signal-to-noise ratio
(SNR)], figures indicating the dilution of precision (DOP) due to geometric constraints in radiolocation systems, and
system-specific figure of merit (FOM).
4.20
positional accuracy
closeness of coordinate (4.3) value to the true or accepted value in a specified reference system
NOTE The phrase “absolute accuracy” is sometimes used for this concept to distinguish it from relative positional
accuracy. Where the true coordinate value may not be perfectly known, accuracy is normally tested by comparison to
available values that can best be accepted as true.
4.21
positioning system
system of instrumental and computational components for determining position
NOTE Examples include inertial, integrated, linear, optical and satellite positioning systems.
4.22
precision
measure of the repeatability of a set of measurements
NOTE Precision is usually expressed as a statistical value based upon a set of repeated measurements, such as the
standard deviation from the sample mean.
4 © ISO 2004 – All rights reserved

4.23
relative position
position of a point with respect to the positions of other points
NOTE The spatial relationship of one point relative to another may be one-, two- or three-dimensional.
4.24
relative positional accuracy
closeness of coordinate (4.3) difference value to the true or accepted value in a specified reference system
NOTE Closely related terms such as local accuracy are employed in various countries, agencies and application
groups. Where such terms are utilized, it is necessary to provide a description of the term.
4.25
satellite positioning system
positioning system (4.21) based upon receipt of signals broadcast from satellites
NOTE In this context, satellite positioning implies the use of radio signals transmitted from “active” artificial objects
orbiting the Earth and received by “passive” instruments on or near the Earth’s surface to determine position, velocity,
and/or attitude of an object. Examples are GPS and GLONASS.
4.26
uncertainty
parameter, associated with the result of measurement, that characterizes the dispersion of values that could
reasonably be attributed to the measurand
[GUM]
NOTE When the quality of accuracy or precision of measured values, such as coordinates, is to be characterized
quantitatively, the quality parameter is an estimate of the uncertainty of the measurement results. Because accuracy is a
qualitative concept, one should not use it quantitatively, that is associate numbers with it; numbers should be associated
with measures of uncertainty instead.
4.27
unit of measure
reference quantity chosen from a unit equivalence group
[adapted from ISO 31-0, 2.1]
NOTE In positioning services, the usual units of measurement are either angular units or linear units.
Implementations of positioning services must clearly distinguish between SI units and non-SI units. When non-SI units are
employed, it is required that their relation to SI units be specified.
4.28
vertical datum
datum (4.6) describing the relation of gravity-related heights (4.9) to the Earth
[ISO 19111]
NOTE In most cases, the vertical datum will be related to a defined mean sea level based on water level
observations over a long time period. Ellipsoidal heights are treated as related to a three-dimensional ellipsoidal
coordinate system referenced to a geodetic datum. Vertical datums include sounding datums (used for hydrographic
purposes), in which case the heights may be negative heights or depths.
5 Symbols, abbreviations and UML notations
5.1 Symbols and abbreviated terms
C/A Coarse / Acquisition code transmissions of the GPS and GLONASS
CRS Coordinate Reference System
DOP Dilution of Precision
DGPS Differential GPS
FOM Figure of Merit
GDOP Geometric Dilution of Precision
GIS Geographic Information System
GLONASS GLObal NAvigation Satellite System (Russian Federation)
GNSS Global Navigation Satellite System (generic)
GPS Global Positioning System (USA)
HDOP Horizontal Dilution of Precision
ITRF International Terrestrial Reference Frame
Ln Signal transmission in a specified portion of the L band of the radio spectrum; suffix “n”
indicates portion of the band for a defined frequency such as GPS L1 or GLONASS L1
LORAN-C LOcation and RANging radiolocation system
NADyy North American Datum; suffix “” indicates last two digits of year
NMEA National Marine Electronics Association
PDOP Positional Dilution of Precision
PPS Precise Positioning Service of a Global Navigation Satellite System
RAIM Receiver Autonomous Integrity Monitoring
RINEX Receiver INdependent EXchange Format
RMS Root Mean Square
RMSE Root Mean Square Error
SI System of Units
SNR Signal to Noise Ratio
SV Space Vehicle
TDOP Time Dilution of Precision
UML Unified Modeling Language
6 © ISO 2004 – All rights reserved

UTM Universal Transverse Mercator
UTC Coordinated Universal Time
VDOP Vertical Dilution of Precision
WAAS Wide Area Augmentation System
5.2 UML Notations
The diagrams that appear in this International Standard are presented using the Unified Modeling Language
(UML). Some important elements of UML notation are shown in Figure 3.

Figure 3 — UML Notation
5.3 UML model stereotypes
A UML stereotype is an extension mechanism for existing UML concepts. It is a model element that is used to
classify (or mark) other UML elements so that they, in some respect, behave as if they were instances of new
virtual or pseudo metamodel classes whose form is based on existing base metamodel classes. Stereotypes
augment the classification mechanisms on the basis of the built-in UML metamodel class hierarchy. Below are
brief descriptions of the stereotypes used in this International Standard. For more detailed descriptions,
consult ISO/TS 19103.
In this International Standard the following stereotypes are used.
a) <> descriptor of a set of values that lack identity (independent existence and the possibility
of side effects). Data types include primitive predefined types and user-definable types.
A DataType is thus a class with few or no operations, whose primary purpose is to hold
the abstract state of another class.
b) <> used to describe an open list. <> is a flexible enumeration. Code lists are
useful for expressing a long list of potential values. If the elements of the list are
completely known, an enumeration should be used; if the only likely values of the
elements are known, a code list should be used.
c) <> class (or other classifier) that cannot be directly instantiated. UML notation for this to
show the name in italics.
d) <> named set of operations that characterize the behaviour of an element.
e) <> cluster of logically related components, containing sub-packages.
5.4 Package abbreviations
Two letter abbreviations are used to denote the package that contains a class. These abbreviations precede
class names, connected by a “_”. A list of these abbreviations follows, together with a reference to the
International Standard in which these classes are located.
CC Changing coordinates (ISO 19111)
CI Citation (ISO 19115)
DQ Data quality (ISO 19115)
EX Extent (ISO 19115)
MD Metadata (ISO 19115)
PS Positioning services (ISO 19116)
RS Reference system (ISO 19115)
SC Spatial coordinates (ISO 19111)
TM Temporal (ISO 19108)
6 Positioning services model
6.1 Introduction
Positioning services provide a means to obtain position information regarding a point or object. The data
communication with a positioning service shall be structured in three classes:
a) System information — held in the PS_System class, identifying the system and its capabilities;
b) Session information — held in the PS_Session class, identifying a session of system operation;
c) Mode information — held in the PS_ObservationMode class, identifying the configuration used in each
mode of operation, the positioning observations (results) and any associated quality information.
These classes apply elements defined in certain other ISO standards as shown in Figure 4, depicting the
relationships among these elements as UML packages.
8 © ISO 2004 – All rights reserved

Figure 4 — Package diagram showing relationship with elements in other ISO standards
6.2 Static data structures of positioning services classes
The service is accessed through an interface that operates on these data classes, creating and destroying
instances as necessary, and setting and getting information needed from the positioning service. This
International Standard can be implemented as an interface between software modules within a system or as
an interface between different systems. The relationships among these classes are depicted in Figure 5, and
the details of these classes are discussed in Clause 7.

Figure 5 — UML depiction of the major data classes of positioning services
System information (PS_System) provides for identification and characterization of the positioning
instrument(s) applied by the positioning service to make observations so that any necessary details can be
obtained for operational purposes and for legacy metadata.
Observation mode information (PS_ObservationMode) encompasses all configuration and set-up parameters,
including the spatial and temporal reference systems on which the observation results are cast. Associated
with the mode may be data-quality configuration information, held in the PS_QualityElement class, that
characterizes how quality results will be evaluated and expressed.
Positioning services can produce several types of observation: position, orientation (attitude), motion and
rotation (angular motion). Because each type of observation shall be cast in its own type of reference system,
a separate instance of the PS_ObservationMode class is created for each type of observation and the type is
an attribute of the mode.
Observations are aggregated to each mode so that the information needed for interpretation is associated with
each observation. A positioning service can create as many mode instances as needed for its various
observation types and reference systems. Numerous observation results can belong to each mode.
Observations aggregated to modes of operation (PS_ObservationMode) can be further aggregated in
sessions (PS_Session). The concept of observation sessions is widely employed when positioning
observations are recorded for land survey or GIS applications. Sessions associate the observations with
system information, attributes of the session, and all the modes of operation employed in making a discrete
group of positioning observations and any associated quality information. Positioning services that do not
provide for the recording of observation results, such as certain navigation systems, may omit implementation
of the PS_Session class.
Positioning-result information is segregated from configuration information in order to avoid excessive
repetition of the configuration when the positioning service reports numerous observations. Similarly, quality-
result information is segregated at the same level as positioning results, so that numerous quality reports of
the same type, evaluated by the same procedure, can be reported without repetition of the element
identification and evaluation procedure citation.
Quality results are associated directly with positioning observation results, and are held in the
PS_ObservationQuality class, which is a subtype of the DQ_QualityMeasure class.
6.3 Positioning services operations
6.3.1 Definition of positioning services operations
The operations of the positioning service interface create, set, get and end (destroy) instances of these
classes as needed to convey the configuration and observation information, and are listed in Figure 6.
10 © ISO 2004 – All rights reserved

Figure 6 — Operations of positioning services
These positioning service operations are described below.
 getSystemInfo() shall cause the positioning service to return a result object of the PS_System class with
attribute values reflecting current information regarding the description of the positioning service itself.
 setSystemInfo(initialization) shall cause the positioning service to set current information regarding the
description of the positioning service itself to values held in an argument 'initialization' that is of the
PS_System class.
 getInstrumentID() shall cause the positioning service to return a result object of the PS_InstrumentID
class with attribute values reflecting current information regarding the identification of the instrumentation
employed by the positioning service for the determination of positioning observations. Because the
identification of instrumentation is often used for traceability and authentication of results, setting of
identification parameters such as model and serial number is performed by the manufacturer or by
authorized operators using means outside the scope of the ISO positioning-services interface.
 newSession(sessionID) shall cause the positioning service to create one instance of a data object of the
PS_Session class populated with current values of parameters identifying an operating session of the
service and set the current value of its sessionID attribute to the value contained in the argument
'sessionID', which is of the CharacterString type. The PS_Session object so created shall be enabled to
aggregate one or more instances of objects of the PS_Operating mode class within it, and thereby
aggregate one or more positioning observations and quality measures within each PS_OperatingMode
object.
 setSessionInfo(sessionID, sessionInfo) shall cause the positioning service to set current information
describing an object of the PS_Session class, of which the sessionID attribute value matches the
sessionID argument value, to the values contained in the sessionInfo argument, which is of the
PS_Session class.
 getSessionInfo(sessionID : CharacterString) shall cause the positioning service to get current information
describing an object of the PS_Session class.
 endSession(sessionID) shall cause the positioning service to disable aggregation of operating mode class
objects to the instance of a PS_Session class object that has a sessionID attribute value matching the
sessionID argument value of the operation and cause all instances of PS_ObservationMode objects
within it to cease aggregating positioning observations and quality measures.
 newMode(name) shall cause the positioning service to create an instance of the PS_ObservationMode
class and assign to its 'name' attribute the value of the 'name' argument of the operation, associate it with
the currently active instance of the PS_Session class if such exists, and enable it to aggregate one or
more PS_Observation objects and associate with zero or more PS_QualityElement objects with their
aggregation of PS_QualityResult objects that associate with PS_Observation objects as their
resultQuality.
 setObservationMode(name, desiredObservationMode) shall cause the positioning service to set operating
mode parameters of the positioning instruments employed to the values contained in the
desiredObservationMode argument so far as possible, and to set the values of the PS_ObservationMode
attributes to reflect the operating mode actually achieved.
 getObservationMode(name) shall cause the positioning service to return a result object of the
PS_ObservationMode class with attributes holding the current values of the instance of
PS_ObservationMode with a name attribute matching the value of the name argument.
 endObservationMode(name) shall cause the positioning service to disable the instance of
PS_ObservationMode with name attribute matching the value of the name argument from aggregating
PS_Observation objects, from associating with PS_QualityElement objects and any aggregated
PS_QualityResult objects, and destroy that instance of PS_ObservationMode.
 getObservation(PS_ObservationMode.name) shall cause the positioning service to return a result object
of the PS_Observation type with attributes reflecting the current position values including the dateTime of
observation and the result vector. The observation may optionally be associated with PS_QualityResult(s)
obtained by use of the getPositionQuality operation.
 setQualityElement(PS_ObservationMode.Name, desiredQualityElement) shall cause the Positioning
service to create an instance of the PS_QualityElement class having attributes with the values contained
in the desiredQualityElement argument and associate it with the PS_ObservationMode instance with a
name attribute matching the PS_ObservationMode.name argument and to act upon the instruments and
computational components of the positioning service to effect the performance of quality evaluations of
the positioning observations in accordance with the desiredQualityElement argument.
 getQualityElement(PS_ObservationMode.name) shall cause the positioning service to return a result
object of the PS_QualityElement class with attributes reflecting the currently selected quality evaluation
parameters associated with the PS_ObservationMode instance with a name attribute matching the value
of the PS_ObservationMode.name argument.
 getPositionQuality shall cause the positioning service to return a result object of the PS_QualityResult
type with attributes reflecting the results of quality evaluation performed upon the currently associated
PS_Observation by the procedures specified in the PS_QualityElement instance associated with this
PS_ObservationMode instance.
 setOperatingConditions(instrumentName, desiredOperatingConditions) shall cause the positioning
service to set user adjustable parameters of the instrument with a name matching the instrumentName
argument to the values contained in the desiredOperatingCondtitions. Note that technological and
manufacturing considerations are outside the scope of this standard and therefore not all technology-
specific operating conditions are required to be adjustable by the user through the use of the
setOperatingConditions operation.
 getOperatingConditions(instrumentName) shall cause the positioning service to return a result object of
the PS_OperatingConditions class with attributes reflecting the current operating conditions of the
instrument with a name matching the instrumentName argument.
12 © ISO 2004 – All rights reserved

 getPerformanceIndicators(instrumentName) shall cause the positioning service to return a result object of
the PS_PerformanceIndicators class with attributes reflecting the current performance indicators of the
instrument with a name matching the instrumentName argument.
 getMeasurementConditions(instrumentName) shall cause the positioning service to return a result object
of the PS_MeasurementConditions class with attributes reflecting the current measurement conditions of
the instrument with a name matching the instrumentName argument.
6.3.2 Applying the positioning services operations
Naturally, one of the primary operations of a positioning service is getObservation, which returns an instance
of the PS_Observation. Among the attributes of the PS_Observation class are the positioning result values,
offsets and object identification. The PS_Observation class may also be associated with one or more
PS_ObservationQuality classes containing quality results. Technology-specific data are reported in the
operatingConditions attribute of the observation. This International Standard does not require that operations
be performed in any specific sequence, because it is recognized that various implementations will perform
these operations in sequences appropriate to various uses of the systems. If operations are requested in a
sequence that is illogical or not supported by an implementation of a positioning service, the service shall
respond with a null result without disruption of operation.
Positioning services do not directly provide the metadata structures specified in ISO 19115, but provide data
classes from which such standard metadata can readily be derived when needed. Metadata supporting the
interpretation of the position values are provided by the getSystemInfo operation and the getMode operation,
which return the PS_System and PS_ObservationMode classes, respectively. In the PS_System class are
values that indicate the type of technology employed in the positioning instrumentation, how it represents
position, and identifies the specific instruments employed. In the PS_ObservationMode class are the
configuration parameters pertaining to the generation of particular types of positioning results, such as the
temporal and spatial reference systems. Associated with the PS_ObservationMode may be
PS_QualityElement instances holding quality evaluation and reporting configuration information.
Additional metadata supportin
...

SLOVENSKI STANDARD
01-september-2004
Geografske informacije – Lokacijske storitve
Geographic information -- Positioning services
Information géographique -- Services de positionnement
Ta slovenski standard je istoveten z: ISO 19116:2004
ICS:
35.240.70 Uporabniške rešitve IT v IT applications in science
znanosti
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 19116
First edition
2004-07-01
Geographic information — Positioning
services
Information géographique — Services de positionnement

Reference number
©
ISO 2004
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ii © ISO 2004 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Conformance . 1
3 Normative references . 1
4 Terms and definitions. 2
5 Symbols, abbreviations and UML notations . 6
5.1 Symbols and abbreviated terms. 6
5.2 UML Notations. 7
5.3 UML model stereotypes. 7
5.4 Package abbreviations . 8
6 Positioning services model . 8
6.1 Introduction . 8
6.2 Static data structures of positioning services classes. 9
6.3 Positioning services operations. 10
6.4 Basic and Extended Information . 13
7 Basic information definition and description. 14
7.1 Introduction . 14
7.2 System Information. 15
7.3 Session. 19
7.4 Mode of operation . 20
7.5 Quality information . 35
8 Technology-specific information . 38
8.1 Introduction . 38
8.2 GNSS Operating Conditions . 38
8.3 Raw measurement data. 43
Annex A (normative) Conformance . 44
Annex B (informative) Implementing accuracy reports for positioning services. 47
Bibliography . 51

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 19116 was prepared by Technical Committee ISO/TC 211, Geographic information/Geomatics.
iv © ISO 2004 – All rights reserved

Introduction
0.1 General
Positioning services are among the processing services identified in ISO 19119. Processing services include
services that are computationally oriented and operate upon the elements from the model domain, rather than
being directly integrated in the model domain itself. This International Standard defines and describes the
positioning service. Other services in this domain are coordinate transformation, metric translation, format
conversion, semantic translation, etc.
Positioning services employ a wide variety of technologies that provide position and related information to a
similarly wide variety of applications, as depicted in Figure 1. Although these technologies differ in many
respects, there are important items of information that are common among them and serve common needs of
these application areas, such as the position data, time of observation and its accuracy. Also, there are items
of information that apply only to specific technologies and are sometimes required in order to make correct
use of the positioning results, such as signal strength, geometry factors, and raw measurements. Therefore,
this International Standard includes both general data elements that are applicable to a wide variety of
positioning services and technology specific elements that are relevant to particular technologies.

Figure 1 — Positioning services interface allows communication of position data for a wide variety of
positioning technologies and users
Modern electronic positioning technology can measure the coordinates of a location on or near the Earth with
great speed and accuracy, thereby allowing geographic information systems to be populated with any number
of objects. However, the technologies for position determination have had neither a common structure for
expression of position information, nor a common structure for expression of accuracy. The positioning-
services interface specified in this International Standard provides data structures and operations that allow
spatially oriented systems, such as GIS, to employ these technologies with greater efficiency by permitting
interoperability among various implementations and various technologies.
This interface may be applied to communication among any of the components of systems that generate and
use position information. Such systems may incorporate an instrument providing position updates to one or
more position-using devices for data processing, storage, and display. For example, a navigation display
system may include recording functions that store the history of a vehicle’s movement, processing tools that
compute guidance updates along a planned course relying on stored waypoints, and a display device that
provides the navigator with current position, computed guidance information, and cartography from stored
coordinate information. This International Standard specifies an interface that carries position and related
information among any of these components, and should be sufficient for communication between the position
providing device and any connected position using devices. Additional interfaces may also exist in such a
system, for example providing for cartographic portrayal of stored coordinate information, which are outside
the scope of this International Standard.
Standard positioning services provide client systems with operations that access positioning results and
related information in a uniform manner, isolating the client from the multiplicity of protocols that may be
employed to communicate with the positioning instruments. For example, a realized-positioning service could
communicate with a GNSS receiver using the well-known NMEA 0183 protocol, translate the information, and
provide the positioning results to a geographic information display client through the ISO 19116 standard
interface specified in this document. Another realized-positioning service could communicate with a GNSS
receiver using a manufacturer's proprietary binary protocol. Through the use of standardized positioning
service interfaces, the hardware communication protocols become transparent to the client application.
Evolution of new communication protocols that closely follow the data structures described in this International
Standard is also anticipated. Such communication standards will facilitate efficient fulfilment of the information
requirements of the positioning services interface and facilitate modular interchangeability of the positioning
technology components.
0.2 Potential use of the service
The application of this International Standard is illustrated in Figure 2 by a simplified case for a user obtaining
coordinates from a GNSS receiver.

Figure 2 — Use case for getting coordinates from a positioning service
vi © ISO 2004 – All rights reserved

First, the positioning service device transmits system-identification data so that the user can determine the
type of positioning system, in this case a GNSS receiver, and whether the system is operational.
Next, the user sets the GNSS receiver to provide coordinates in the desired Coordinate Reference System
(CRS) through the interface by performing setMode operations. For instance, the coordinate reference system
could be set to NAD27 Virginia State Plane, North Zone, US Survey feet. Note that by using well-recognized
CRS names in accordance with the ISO 19111 structure, the user avoids some of the complexity of the
definition of the coordinate reference system by using a named datum and mapping projection, and the
system interprets these and loads predefined set of parameters.
By performing technology-specific setOperatingConditions operations, the user also sets certain operating
conditions of the system so that the position determination will be performed in a desired manner. For
example, the user sets the satellite-elevation mask of the GNSS receiver so that satellites that are at low
angles in the sky, and consequently, more affected by signal passage through the atmosphere, are excluded
from the computation. Certain other operating conditions, such as the current actual positions of available
satellites, are not controllable by the user and are determined by the system.
The system then performs measurements according to the operating conditions of the signal from the GNSS
satellites and uses these measurements to compute a position cast in the specified Coordinate Reference
System.
Finally, the computed position is reported to the user through the PS_Observation data object.
The positioning system also reports on certain operating conditions to help the user decide whether to use the
position value. For example, one of the indicators of solution quality is the dilution of precision (DOP) value,
which is based on the geometry of the satellites observed to determine the position.
Communication of this information is performed through the standard data structures to the user’s display
device, which portrays it to the user.

INTERNATIONAL STANDARD ISO 19116:2004(E)

Geographic information — Positioning services
1 Scope
This International Standard specifies the data structure and content of an interface that permits
communication between position-providing device(s) and position-using device(s) so that the position-using
device(s) can obtain and unambiguously interpret position information and determine whether the results meet
the requirements of the use. A standardized interface of geographic information with position allows the
integration of positional information from a variety of positioning technologies into a variety of geographic
information applications, such as surveying, navigation and intelligent transportation systems. This
International Standard will benefit a wide range of applications for which positional information is important.
2 Conformance
This International Standard defines two levels of conformance: Basic (that all implementations shall meet) and
Extended (for technology-specific data related to a positioning system). Any positioning services
implementation or product claiming conformance with this part of the International Standard shall pass all the
requirements described in the corresponding abstract test suite set forth in Annex A.
3 Normative references
The following referenced documents are indispensable for the application 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 1000:1992, SI units and recommendations for the use of their multiples and of certain other units
1)
ISO/TS 19103:— , Geographic information — Conceptual schema language
ISO 19108:2002, Geographic information — Temporal schema
ISO 19111:2003, Geographic information — Spatial referencing by coordinates
ISO 19113:2002, Geographic information — Quality principles
ISO 19114:2003, Geographic information — Quality evaluation procedures
ISO 19115:2003, Geographic information — Metadata

1) To be published.
4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
accuracy
closeness of agreement between a test result and the accepted reference value
[ISO 3534-1]
NOTE For positioning services, the test result is a measured value or set of values.
4.2
attitude
orientation of a body, described by the angles between the axes of that body’s coordinate system (4.5) and
the axes of an external coordinate system (4.5)
NOTE In positioning services, this is usually the orientation of the user’s platform, such as an aircraft, boat, or
automobile.
4.3
coordinate
one of a sequence of n numbers designating the position of a point in n-dimensional space
[ISO 19111]
NOTE In a coordinate reference system, the numbers must be qualified by units.
4.4
coordinate reference system
coordinate system (4.5) that is related to the real world by a datum (4.6)
[ISO 19111]
NOTE For geodetic and vertical datums, it will be related to the Earth.
4.5
coordinate system
set of mathematical rules for specifying how coordinates (4.3) are to be assigned to points
[ISO 19111]
4.6
datum
parameter or set of parameters that serve as a reference or basis for the calculation of other parameters
[ISO 19111]
NOTE 1 A datum defines the position of the origin, the scale, and the orientation of the axes of a coordinate system.
NOTE 2 A datum may be a geodetic datum, a vertical datum or an engineering datum.
4.7
ellipsoidal height
geodetic height
h
distance of a point from the ellipsoid measured along the perpendicular from the ellipsoid to this point, positive
if upwards or outside of the ellipsoid
[ISO 19111]
NOTE Only used as part of a three-dimensional geodetic coordinate system and never on its own.
2 © ISO 2004 – All rights reserved

4.8
geodetic datum
datum (4.6) describing the relationship of a coordinate system (4.5) to the Earth
[ISO 19111]
NOTE In most cases, the geodetic datum includes an ellipsoid definition.
4.9
gravity-related height
H
height (4.10) dependent on the Earth’s gravity field
[ISO 19111]
NOTE In particular, orthometric height or normal height, which are both approximations of the distance of a point
above the mean sea level.
4.10
height
altitude
h
H
distance of a point from a chosen reference surface along a line perpendicular to that surface
[ISO 19111]
NOTE 1 See ellipsoidal height and gravity-related height.
NOTE 2 Height of a point outside the surface treated as positive; negative height is designated as depth.
4.11
inertial positioning system
positioning system (4.21) employing accelerometers, gyroscopes, and computers as integral components to
determine coordinates (4.3) of points or objects relative to an initial known reference point
4.12
integrated positioning system
positioning system (4.21) incorporating two or more positioning technologies
NOTE The measurements produced by each positioning technology in an integrated system may be of any position,
motion, or attitude. There may be redundant measurements. When combined, a unified position, motion, or attitude is
determined.
4.13
linear positioning system
positioning system (4.21) that measures distance from a reference point along a route
EXAMPLE An odometer used in conjunction with predefined mile or kilometre origin points along a route and
provides a linear reference to a position.
4.14
linear reference system
reference system that identifies a location by reference to a segment of a linear geographic feature and
distance along that segment from a given point
NOTE Linear reference systems are widely used in transportation, for example highway names and mile or kilometre
markers.
4.15
map projection
coordinate (4.3) conversion from a geodetic coordinate system (4.5) to a plane
[ISO 19111]
4.16
motion
change in the position of an object over time, represented by change of coordinate (4.3) values with respect
to a particular reference frame
EXAMPLE This may be motion of the position sensor mounted on a vehicle or other platform or motion of an object
being tracked by a positioning system.
4.17
operating conditions
parameters influencing the determination of coordinate (4.3) values by a positioning system (4.21)
NOTE Measurements acquired in the field are affected by many instrumental and environmental factors, including
meteorological conditions, computational methods and constraints, imperfect instrument construction, incomplete
instrument adjustment or calibration, and, in the case of optical measuring systems, the personal bias of the observer.
Solutions for positions may be affected by the geometric relationships of the observed data and/or mathematical model
employed in the processing software.
4.18
optical positioning system
positioning system (4.21) that determines the position of an object by means of the properties of light
EXAMPLE Total Station: Commonly used term for an integrated optical positioning system incorporating an
electronic theodolite and an electronic distance-measuring instrument into a single unit with an internal microprocessor for
automatic computations.
4.19
performance indicator
internal parameters of positioning systems (4.21) indicative of the level of performance achieved
NOTE Performance indicators can be used as quality-control evidence of the positioning system and/or positioning
solution. Internal quality control may include such factors as signal strength of received radio signals [signal-to-noise ratio
(SNR)], figures indicating the dilution of precision (DOP) due to geometric constraints in radiolocation systems, and
system-specific figure of merit (FOM).
4.20
positional accuracy
closeness of coordinate (4.3) value to the true or accepted value in a specified reference system
NOTE The phrase “absolute accuracy” is sometimes used for this concept to distinguish it from relative positional
accuracy. Where the true coordinate value may not be perfectly known, accuracy is normally tested by comparison to
available values that can best be accepted as true.
4.21
positioning system
system of instrumental and computational components for determining position
NOTE Examples include inertial, integrated, linear, optical and satellite positioning systems.
4.22
precision
measure of the repeatability of a set of measurements
NOTE Precision is usually expressed as a statistical value based upon a set of repeated measurements, such as the
standard deviation from the sample mean.
4 © ISO 2004 – All rights reserved

4.23
relative position
position of a point with respect to the positions of other points
NOTE The spatial relationship of one point relative to another may be one-, two- or three-dimensional.
4.24
relative positional accuracy
closeness of coordinate (4.3) difference value to the true or accepted value in a specified reference system
NOTE Closely related terms such as local accuracy are employed in various countries, agencies and application
groups. Where such terms are utilized, it is necessary to provide a description of the term.
4.25
satellite positioning system
positioning system (4.21) based upon receipt of signals broadcast from satellites
NOTE In this context, satellite positioning implies the use of radio signals transmitted from “active” artificial objects
orbiting the Earth and received by “passive” instruments on or near the Earth’s surface to determine position, velocity,
and/or attitude of an object. Examples are GPS and GLONASS.
4.26
uncertainty
parameter, associated with the result of measurement, that characterizes the dispersion of values that could
reasonably be attributed to the measurand
[GUM]
NOTE When the quality of accuracy or precision of measured values, such as coordinates, is to be characterized
quantitatively, the quality parameter is an estimate of the uncertainty of the measurement results. Because accuracy is a
qualitative concept, one should not use it quantitatively, that is associate numbers with it; numbers should be associated
with measures of uncertainty instead.
4.27
unit of measure
reference quantity chosen from a unit equivalence group
[adapted from ISO 31-0, 2.1]
NOTE In positioning services, the usual units of measurement are either angular units or linear units.
Implementations of positioning services must clearly distinguish between SI units and non-SI units. When non-SI units are
employed, it is required that their relation to SI units be specified.
4.28
vertical datum
datum (4.6) describing the relation of gravity-related heights (4.9) to the Earth
[ISO 19111]
NOTE In most cases, the vertical datum will be related to a defined mean sea level based on water level
observations over a long time period. Ellipsoidal heights are treated as related to a three-dimensional ellipsoidal
coordinate system referenced to a geodetic datum. Vertical datums include sounding datums (used for hydrographic
purposes), in which case the heights may be negative heights or depths.
5 Symbols, abbreviations and UML notations
5.1 Symbols and abbreviated terms
C/A Coarse / Acquisition code transmissions of the GPS and GLONASS
CRS Coordinate Reference System
DOP Dilution of Precision
DGPS Differential GPS
FOM Figure of Merit
GDOP Geometric Dilution of Precision
GIS Geographic Information System
GLONASS GLObal NAvigation Satellite System (Russian Federation)
GNSS Global Navigation Satellite System (generic)
GPS Global Positioning System (USA)
HDOP Horizontal Dilution of Precision
ITRF International Terrestrial Reference Frame
Ln Signal transmission in a specified portion of the L band of the radio spectrum; suffix “n”
indicates portion of the band for a defined frequency such as GPS L1 or GLONASS L1
LORAN-C LOcation and RANging radiolocation system
NADyy North American Datum; suffix “” indicates last two digits of year
NMEA National Marine Electronics Association
PDOP Positional Dilution of Precision
PPS Precise Positioning Service of a Global Navigation Satellite System
RAIM Receiver Autonomous Integrity Monitoring
RINEX Receiver INdependent EXchange Format
RMS Root Mean Square
RMSE Root Mean Square Error
SI System of Units
SNR Signal to Noise Ratio
SV Space Vehicle
TDOP Time Dilution of Precision
UML Unified Modeling Language
6 © ISO 2004 – All rights reserved

UTM Universal Transverse Mercator
UTC Coordinated Universal Time
VDOP Vertical Dilution of Precision
WAAS Wide Area Augmentation System
5.2 UML Notations
The diagrams that appear in this International Standard are presented using the Unified Modeling Language
(UML). Some important elements of UML notation are shown in Figure 3.

Figure 3 — UML Notation
5.3 UML model stereotypes
A UML stereotype is an extension mechanism for existing UML concepts. It is a model element that is used to
classify (or mark) other UML elements so that they, in some respect, behave as if they were instances of new
virtual or pseudo metamodel classes whose form is based on existing base metamodel classes. Stereotypes
augment the classification mechanisms on the basis of the built-in UML metamodel class hierarchy. Below are
brief descriptions of the stereotypes used in this International Standard. For more detailed descriptions,
consult ISO/TS 19103.
In this International Standard the following stereotypes are used.
a) <> descriptor of a set of values that lack identity (independent existence and the possibility
of side effects). Data types include primitive predefined types and user-definable types.
A DataType is thus a class with few or no operations, whose primary purpose is to hold
the abstract state of another class.
b) <> used to describe an open list. <> is a flexible enumeration. Code lists are
useful for expressing a long list of potential values. If the elements of the list are
completely known, an enumeration should be used; if the only likely values of the
elements are known, a code list should be used.
c) <> class (or other classifier) that cannot be directly instantiated. UML notation for this to
show the name in italics.
d) <> named set of operations that characterize the behaviour of an element.
e) <> cluster of logically related components, containing sub-packages.
5.4 Package abbreviations
Two letter abbreviations are used to denote the package that contains a class. These abbreviations precede
class names, connected by a “_”. A list of these abbreviations follows, together with a reference to the
International Standard in which these classes are located.
CC Changing coordinates (ISO 19111)
CI Citation (ISO 19115)
DQ Data quality (ISO 19115)
EX Extent (ISO 19115)
MD Metadata (ISO 19115)
PS Positioning services (ISO 19116)
RS Reference system (ISO 19115)
SC Spatial coordinates (ISO 19111)
TM Temporal (ISO 19108)
6 Positioning services model
6.1 Introduction
Positioning services provide a means to obtain position information regarding a point or object. The data
communication with a positioning service shall be structured in three classes:
a) System information — held in the PS_System class, identifying the system and its capabilities;
b) Session information — held in the PS_Session class, identifying a session of system operation;
c) Mode information — held in the PS_ObservationMode class, identifying the configuration used in each
mode of operation, the positioning observations (results) and any associated quality information.
These classes apply elements defined in certain other ISO standards as shown in Figure 4, depicting the
relationships among these elements as UML packages.
8 © ISO 2004 – All rights reserved

Figure 4 — Package diagram showing relationship with elements in other ISO standards
6.2 Static data structures of positioning services classes
The service is accessed through an interface that operates on these data classes, creating and destroying
instances as necessary, and setting and getting information needed from the positioning service. This
International Standard can be implemented as an interface between software modules within a system or as
an interface between different systems. The relationships among these classes are depicted in Figure 5, and
the details of these classes are discussed in Clause 7.

Figure 5 — UML depiction of the major data classes of positioning services
System information (PS_System) provides for identification and characterization of the positioning
instrument(s) applied by the positioning service to make observations so that any necessary details can be
obtained for operational purposes and for legacy metadata.
Observation mode information (PS_ObservationMode) encompasses all configuration and set-up parameters,
including the spatial and temporal reference systems on which the observation results are cast. Associated
with the mode may be data-quality configuration information, held in the PS_QualityElement class, that
characterizes how quality results will be evaluated and expressed.
Positioning services can produce several types of observation: position, orientation (attitude), motion and
rotation (angular motion). Because each type of observation shall be cast in its own type of reference system,
a separate instance of the PS_ObservationMode class is created for each type of observation and the type is
an attribute of the mode.
Observations are aggregated to each mode so that the information needed for interpretation is associated with
each observation. A positioning service can create as many mode instances as needed for its various
observation types and reference systems. Numerous observation results can belong to each mode.
Observations aggregated to modes of operation (PS_ObservationMode) can be further aggregated in
sessions (PS_Session). The concept of observation sessions is widely employed when positioning
observations are recorded for land survey or GIS applications. Sessions associate the observations with
system information, attributes of the session, and all the modes of operation employed in making a discrete
group of positioning observations and any associated quality information. Positioning services that do not
provide for the recording of observation results, such as certain navigation systems, may omit implementation
of the PS_Session class.
Positioning-result information is segregated from configuration information in order to avoid excessive
repetition of the configuration when the positioning service reports numerous observations. Similarly, quality-
result information is segregated at the same level as positioning results, so that numerous quality reports of
the same type, evaluated by the same procedure, can be reported without repetition of the element
identification and evaluation procedure citation.
Quality results are associated directly with positioning observation results, and are held in the
PS_ObservationQuality class, which is a subtype of the DQ_QualityMeasure class.
6.3 Positioning services operations
6.3.1 Definition of positioning services operations
The operations of the positioning service interface create, set, get and end (destroy) instances of these
classes as needed to convey the configuration and observation information, and are listed in Figure 6.
10 © ISO 2004 – All rights reserved

Figure 6 — Operations of positioning services
These positioning service operations are described below.
 getSystemInfo() shall cause the positioning service to return a result object of the PS_System class with
attribute values reflecting current information regarding the description of the positioning service itself.
 setSystemInfo(initialization) shall cause the positioning service to set current information regarding the
description of the positioning service itself to values held in an argument 'initialization' that is of the
PS_System class.
 getInstrumentID() shall cause the positioning service to return a result object of the PS_InstrumentID
class with attribute values reflecting current information regarding the identification of the instrumentation
employed by the positioning service for the determination of positioning observations. Because the
identification of instrumentation is often used for traceability and authentication of results, setting of
identification parameters such as model and serial number is performed by the manufacturer or by
authorized operators using means outside the scope of the ISO positioning-services interface.
 newSession(sessionID) shall cause the positioning service to create one instance of a data object of the
PS_Session class populated with current values of parameters identifying an operating session of the
service and set the current value of its sessionID attribute to the value contained in the argument
'sessionID', which is of the CharacterString type. The PS_Session object so created shall be enabled to
aggregate one or more instances of objects of the PS_Operating mode class within it, and thereby
aggregate one or more positioning observations and quality measures within each PS_OperatingMode
object.
 setSessionInfo(sessionID, sessionInfo) shall cause the positioning service to set current information
describing an object of the PS_Session class, of which the sessionID attribute value matches the
sessionID argument value, to the values contained in the sessionInfo argument, which is of the
PS_Session class.
 getSessionInfo(sessionID : CharacterString) shall cause the positioning service to get current information
describing an object of the PS_Session class.
 endSession(sessionID) shall cause the positioning service to disable aggregation of operating mode class
objects to the instance of a PS_Session class object that has a sessionID attribute value matching the
sessionID argument value of the operation and cause all instances of PS_ObservationMode objects
within it to cease aggregating positioning observations and quality measures.
 newMode(name) shall cause the positioning service to create an instance of the PS_ObservationMode
class and assign to its 'name' attribute the value of the 'name' argument of the operation, associate it with
the currently active instance of the PS_Session class if such exists, and enable it to aggregate one or
more PS_Observation objects and associate with zero or more PS_QualityElement objects with their
aggregation of PS_QualityResult objects that associate with PS_Observation objects as their
resultQuality.
 setObservationMode(name, desiredObservationMode) shall cause the positioning service to set operating
mode parameters of the positioning instruments employed to the values contained in the
desiredObservationMode argument so far as possible, and to set the values of the PS_ObservationMode
attributes to reflect the operating mode actually achieved.
 getObservationMode(name) shall cause the positioning service to return a result object of the
PS_ObservationMode class with attributes holding the current values of the instance of
PS_ObservationMode with a name attribute matching the value of the name argument.
 endObservationMode(name) shall cause the positioning service to disable the instance of
PS_ObservationMode with name attribute matching the value of the name argument from aggregating
PS_Observation objects, from associating with PS_QualityElement objects and any aggregated
PS_QualityResult objects, and destroy that instance of PS_ObservationMode.
 getObservation(PS_ObservationMode.name) shall cause the positioning service to return a result object
of the PS_Observation type with attributes reflecting the current position values including the dateTime of
observation and the result vector. The observation may optionally be associated with PS_QualityResult(s)
obtained by use of the getPositionQuality operation.
 setQualityElement(PS_ObservationMode.Name, desiredQualityElement) shall cause the Positioning
service to create an instance of the PS_QualityElement class having attributes with the values contained
in the desiredQualityElement argument and associate it with the PS_ObservationMode instance with a
name attribute matching the PS_ObservationMode.name argument and to act upon the instruments and
computational components of the positioning service to effect the performance of quality evaluations of
the positioning observations in accordance with the desiredQualityElement argument.
 getQualityElement(PS_ObservationMode.name) shall cause the positioning service to return a result
object of the PS_QualityElement class with attributes reflecting the currently selected quality evaluation
parameters associated with the PS_ObservationMode instance with a name attribute matching the value
of the PS_ObservationMode.name argument.
 getPositionQuality shall cause the positioning service to return a result object of the PS_QualityResult
type with attributes reflecting the results of quality evaluation performed upon the currently associated
PS_Observation by the procedures specified in the PS_QualityElement instance associated with this
PS_ObservationMode instance.
 setOperatingConditions(instrumentName, desiredOperatingConditions) shall cause the positioning
service to set user adjustable parameters of the instrument with a name matching the instrumentName
argument to the values contained in the desiredOperatingCondtitions. Note that technological and
manufacturing considerations are outside the scope of this standard and therefore not all technology-
specific operating conditions are required to be adjustable by the user through the use of the
setOperatingConditions operation.
 getOperatingConditions(instrumentName) shall cause the positioning service to return a result object of
the PS_OperatingConditions class with attributes reflecting the current operating conditions of the
instrument with a name matching the instrumentName argument.
12 © ISO 2004 – All rights reserved

 getPerformanceIndicators(instrumentName) shall cause the positioning service to return a result object of
the PS_PerformanceIndicators class with attributes reflecting the current performance indicators of the
instrument with a name matching the instrumentName argument.
 getMeasurementConditions(instrumentName) shall cause the positioning service to return a result object
of the PS_MeasurementConditions class with attributes reflecting the current measurement conditions of
the instrument with a name matching the instrumentName argument.
6.3.2 Applying the positioning services operations
Naturally, one of the primary operations of a positioning service is getObservation, which returns an instance
of the PS_Observation. Among the attributes of the PS_Observation class are the positioning result values,
offsets and object identification. The PS_Observation class may also be associated with one or more
PS_ObservationQuality classes containing quality results. Technology-specific data are reported in the
operatingConditions attribute of the observation. This International Standard does not require that operations
be performed in any specific sequence, because it is recognized that various implementations will perform
these operations in sequences appropriate to various uses of the systems. If operations are requested in a
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