ISO 19116:2025 地理情報 — 測位サービス | ページ 6

3.1

absolute accuracy

external accuracy

closeness of reported coordinate values to values accepted as or being true

Note 1 to entry: Where the true coordinate value is potentially not perfectly known, accuracy is normally tested by comparison to available values that can best be accepted as true.

[SOURCE:ISO/TS 19159-2:2016, 4.1 modified — Notes 1 and 2 to entry have been removed and replaced by a new Note 1 to entry.]

3.2

accuracy

closeness of agreement between a test result or measurement result and the true value

Note 1 to entry: For positioning services, the test result is a measured value or set of values.

[SOURCE:ISO 3534‑2:2006, 3.3.1, modified — Notes 1, 2 and 3 to entry have been deleted and replaced by a new Note 1 to entry.]

3.3

attitude

orientation of a body, described by the angles between the axes of that body’s coordinate system and the axes of an external coordinate system

Note 1 to entry: In positioning services, this is usually the orientation of the user’s platform, such as an aircraft, boat or automobile.

3.4

coordinate

one of a sequence of numbers designating the position of a point

Note 1 to entry: In a spatial coordinate reference system, the coordinate numbers are qualified by units.

[SOURCE:ISO 19111:2019, 3.1.5]

3.5

coordinate conversion

coordinate operation that changes coordinates in a source coordinate reference system to coordinates in a target coordinate reference system in which both coordinate reference systems are based on the same datum

Note 1 to entry: A coordinate conversion uses parameters which have specified values.

[SOURCE:ISO 19111:2019, 3.1.6]

3.6

coordinate operation

process using a mathematical model, based on a one-to-one relationship, that changes coordinates in a source coordinate reference system to coordinates in a target coordinate reference system, or that changes coordinates at a source coordinate epoch to coordinates at a target coordinate epoch within the same coordinate reference system

Note 1 to entry: Generalization of coordinate conversion, coordinate transformation and point motion operation.

[SOURCE:ISO 19111:2019/Amd.1:2021, 3.1.8]

3.7

coordinate reference system

coordinate system that is related to an object by a datum

Note 1 to entry: Geodetic and vertical datums are referred to as reference frames.

Note 2 to entry: For geodetic and vertical reference frames, the object will be the Earth. In planetary applications, geodetic and vertical reference frames may be applied to other celestial bodies.

[SOURCE:ISO 19111:2019, 3.1.9]

3.8

coordinate system

set of mathematical rules for specifying how coordinates are to be assigned to points

[SOURCE:ISO 19111:2019, 3.1.11]

3.9

coordinate transformation

coordinate operation that changes coordinates in a source coordinate reference system to coordinates in a target coordinate reference system in which the source and target coordinate reference systems are based on different datums

Note 1 to entry: A coordinate transformation uses parameters which are derived empirically. Any error in those coordinates will be embedded in the coordinate transformation and when the coordinate transformation is applied the embedded errors are transmitted to output coordinates.

Note 2 to entry: A coordinate transformation is colloquially sometimes referred to as a"datum transformation". This is erroneous. A coordinate transformation changes coordinate values. It does not change the definition of the datum. In this document coordinates are referenced to a coordinate reference system. A coordinate transformation operates between two coordinate reference systems, not between two datums.

[SOURCE:ISO 19111:2019, 3.1.12]

3.10

datum

reference frame

parameter or set of parameters that realize the position of the origin, the scale, and the orientation of a coordinate system

[SOURCE:ISO 19111:2019, 3.1.15]

3.11

height

distance of a point from a chosen reference surface positive upward along a line perpendicular to that surface

Note 1 to entry: A height below the reference surface will have a negative value.

Note 2 to entry: Generalisation of ellipsoidal height (h) and gravity-related height (H).

[SOURCE:ISO 19111:2019, 3.1.38]

3.12

inertial positioning system

positioning system employing accelerometers, gyroscopes and computers as integral components to determine coordinates of points or objects relative to an initial known reference point

3.13

instant

0-dimensional geometric primitive representing position in time

Note 1 to entry: The geometry of time is discussed in ISO 19108:2002, 5.2.

[SOURCE:ISO 19108:2002, 4.1.17]

3.14

integrated positioning system

positioning system incorporating two or more positioning technologies

Note 1 to entry: 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.

3.15

linear positioning system

positioning system that measures distance from a reference point along a route (feature)

3.16

map projection

coordinate conversion from an ellipsoidal coordinate system to a plane

[SOURCE:ISO 19111:2019, 3.1.40]

3.17

measurement precision

precision

closeness of agreement between indications or measured quantity values obtained by replicate measurements on the same or similar objects under specified conditions

Note 1 to entry: Measurement precision is usually expressed numerically by measures of imprecision, such as standard deviation, variance, or coefficient of variation under the specified conditions of measurement.

Note 2 to entry: The"specified conditions" can be, for example, repeatability conditions of measurement, intermediate precision conditions of measurement, or reproducibility conditions of measurement (see ISO 5725-3).

Note 3 to entry: Measurement precision is used to define measurement repeatability, intermediate measurement precision, and measurement reproducibility.

Note 4 to entry: Sometimes"measurement precision" is erroneously used to mean measurement accuracy.

[SOURCE:ISO/IEC Guide 99:2007, 2.15]

3.18

motion

change in the position of an object over time, represented by change of coordinate values with respect to a particular reference frame

3.19

operating conditions

parameters influencing the determination of coordinate values by a positioning system

Note 1 to entry: 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 can be affected by the geometric relationships of the observed data and/or mathematical model employed in the processing software.

3.20

optical positioning system

positioning system that determines the position of an object by means of the properties of light

3.21

performance indicator

internal parameters of positioning systems indicative of the level of performance achieved

Note 1 to entry: 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).

3.22

positional accuracy

closeness of coordinate value to the true or accepted value in a specified reference system

Note 1 to entry: The phrase “absolute accuracy” is sometimes used for this concept to distinguish it from relative positional accuracy. Where the true coordinate value is not perfectly known, accuracy is normally tested by comparison to available values that can best be accepted as true.

3.23

positional reliability

degree to which a positioning service provides agreed or expected absolute accuracy during a defined instant under specified conditions

Note 1 to entry: The wording of the definition has been adapted from ISO/IEC 16350:2015, 4.29 (reliability).

3.24

positioning system

system of instrumental and computational components for determining position

3.25

relative position

position of a point with respect to the positions of other points

Note 1 to entry: The spatial relationship of one point relative to another may be one-, two- or three-dimensional.

3.26

relative accuracy

internal accuracy

closeness of the relative positions of features in a data set to their respective relative positions accepted as or being true

Note 1 to entry: 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.

Note 2 to entry: The wording of this definition is from ISO 19157:2013, 7.3.4, and was later added as a terminology entry by ISO/TS 19159-2:2016, 4.32. Recently, that wording was revised in ISO 19157-1:2023, 8.3.4. This document, however, retains the original wording from ISO 19157:2013, 7.3.4.

[SOURCE:ISO/TS 19159-2:2016, 4.32 modified — Note 1 to entry has been removed and replaced by a new Note 1 to entry and a new Note 2 to entry has been added.]

3.27

satellite positioning system

positioning system based upon receipt of signals broadcast from satellites

Note 1 to entry: 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.

3.28

uncertainty

parameter, associated with the result of measurement, that characterizes the dispersion of values that could reasonably be attributed to the measurand

Note 1 to entry: 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. As accuracy is a qualitative concept, it should not be used quantitatively, i.e. numbers should not be associated with it. Instead, numbers should be associated with measures of uncertainty.

3.29

unit of measure

reference quantity chosen from a unit equivalence group

Note 1 to entry: In positioning services, the usual units of measurement are either angular units or linear units. Implementations of positioning services shall clearly distinguish between SI units and non-SI units. When non-SI units are employed, their relation to SI units shall be specified.