ISO 24245:2023

INTERNATIONAL ISO
STANDARD 24245
First edition
2023-06
Space systems — Global navigation
satellite system (GNSS) receiver class
codes
Systèmes spatiaux — Codification des récepteurs de systèmes
mondiaux de satellites de navigation (GNSS)
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 Code system . 4
5.1 Positioning . 4
5.1.1 General . 4
5.1.2 C10, C10a. 5
5.1.3 C11, C11a . 5
5.1.4 C16, C16a . 5
5.1.5 C20, C20a . 5
5.1.6 C25, C25a . 6
5.1.7 C26, C26a . 6
5.1.8 P06, P06a . 6
5.1.9 P11, P11a . 6
5.1.10 P16, P16a . 6
5.1.11 P21, P21a . 7
5.1.12 P26, P26a . 7
5.2 Timing . 7
5.2.1 General . 7
5.2.2 T1 . 7
5.2.3 T2 . 7
5.3 Messaging . 7
5.3.1 General . 7
5.3.2 M1 . 8
5.3.3 M2 . 8
6 Conditions to classify receivers .8
7 Multiple labelling . 8
Annex A (informative) Examples of GNSS application . 9
Bibliography .15
iii
Foreword
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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
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This document was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles,
Subcommittee SC 14, Space systems and operations.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
This document is a specification of downstream space-based services. Space systems provide a huge
merit for the society and economy in each country today; and downstream space-based services
contribute to people’s quality of life across the world. Space systems should be utilized furthermore
in the industry worldwide in the future. Space systems are utilized in other areas as well. Therefore,
this document has harmonized the content in areas relevant to the global navigation satellite system
(GNSS) as shown in Figure 1.
Figure 1 — Standardization of space-based services (GNSS-relevant areas)
st
In the initial decades of the 21 century, several countries have provided their constellations of GNSS,
and it has been utilized as an international public service. GNSS technology has progressed and become
more complicated, for example, to handle multiple frequencies from multiple constellations, and to
provide services such as carrier-phase measurement, precise point positioning, and so on.
As a result, for users who want to try new GNSS technology, there are too many GNSS receivers to
choose from to find the product matching their needs.
In order to solve this problem, a set of GNSS receiver class codes has been developed. It was released into
the market as a trial program and has received high evaluation from GNSS stakeholders in commercial
and governmental scenes in a certain region. It is recognized to be contributable to the promotion of
GNSS utilization.
The set of GNSS receiver class codes facilitates easier choice for users and sales expansion for sellers; it
also provides the direction of development and business strategies for manufactures and the framework
of policy making for governments and public sectors.
This document aims to promote the utilization of GNSS receiver class codes in the international market
for stakeholders of space-based positioning, navigation and timing services around the world.
The GNSS environment has been drastically improved and more widely used in recent years with the
development GNSS space system infrastructure by several countries.
Against this background, GNSS receivers become diverse and accept multi-constellation. One receiver
also equips various functions. There are receivers for specified regions and timing-dedicated receivers.
This document symbolizes “receiver class” to “codes” from the point of view of positioning, timing, and
messaging functions. Regarding these functions, positioning is for determining the position, timing
is for determining the time or time interval or both, and messaging is for transmitting or receiving
message or both.
v
By using this document, it is expected that end users can understand the types of GNSS signal their
devices receive from navigation satellites. On the other hand, receiver providers can easily present their
products’ features which depend on the signals of the receiver. Figure 2 represents the above effects.
Figure 2 — GNSS receiver class codes for an efficient market
Some GNSS receivers are equipped with the following functions: detection of attitude, mobile
communication using Wi-Fi, etc. This document does not treat these functions.
vi
INTERNATIONAL STANDARD ISO 24245:2023(E)
Space systems — Global navigation satellite system (GNSS)
receiver class codes
1 Scope
This document specifies class codes to classify global navigation satellite system (GNSS) receivers. The
class codes represent how signals transmitted from radionavigation satellites are processed.
This document applies to all types of GNSS receiver devices.
The class codes in this document are not applicable to the following items:
— condition of radionavigation satellites;
— radio propagation environment including multipath, masking and obstacle;
— additional antenna of a receiver device;
— additional application software in a receiver device.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
receiver
device (3.2) with associated antenna or including an antenna, used to select the desired radio-frequency
signals from the incident radio-frequency radiation, to amplify them, demodulate them and if necessary,
convert the recovered signals into a directly usable form
[SOURCE: IEC 60050-713:1998, 713-10-02, Modified — “such as sounds or pictures” has been deleted at
the end of the definition.]
3.2
device
material element or assembly of such elements intended to perform a required function
Note 1 to entry: A device may form part of a larger device.
[SOURCE: IEC 60050-151:2001, 151-11-20]
3.3
GNSS receiver
receiver (3.1) to determine the user position, velocity, and/or precise time by processing the signals
broadcasted by radionavigation (3.6) satellites
3.4
radiodetermination
determination of the position, velocity and/or other characteristics of an object, of the obtaining of
information relating to these characteristics, by means of radio waves
[SOURCE: IEC 60050-725:1994, 725-12-48]
3.5
satellite radiodetermination
radiodetermination (3.4) which makes use of a satellite system
[SOURCE: IEC 60050-725:1994, 725-12-49]
3.6
radionavigation
radiodetermination (3.4) used for the purpose of navigation, including obstruction warning
[SOURCE: IEC 60050-725:1994, 725-12-50]
3.7
satellite radionavigation
satellite radiodetermination (3.5) used for radionavigation (3.6)
[SOURCE: IEC 60050-725:1994, 725-12-51]
3.8
code-based positioning
positioning based on code-phase measurement without integer ambiguity resolution
Note 1 to entry: A code-based positioning receiver (3.1) may be equipped with the carrier-smoothing function.
3.9
phase-range
range measured by using carrier-phase with integer ambiguity resolution
Note 1 to entry: See RTCM standard 10403.3, 3.5.
3.10
state space
space defined by the state variables as axes of a vector space, in which every vector represents a state
of the system
[SOURCE: IEC 60050-351:2013, 351-41-09]
3.11
observation space
space defined by the observation variables as axes of a vector space, in which every vector represents a
observation variable of the system
3.12
SSR
state space representation
representation of a valuable in a state space (3.10)
Note 1 to entry: See RTCM standard 10403.3, 3.5.13.
Note 2 to entry: SSR is a mathematically orthogonal representation of parameters.
3.13
OSR
observation space representation
representation of a valuable in an observation space (3.11)
Note 1 to entry: See RTCM standard 10403.3, 3.5.13.
3.14
GNSS authentication
function to authenticate the signal from GNSS
4 Abbreviated terms
3GPP third generation partnership project (mobile communication)
BDS BeiDou Navigation Satellite System (China)
BIM building information modelling
CIM construction information modelling
CORS continuously operating reference station
DFMC dual frequency and multi constellation
DGNSS differential GNSS
GLONASS NAvigation Satellite System (Russian Federation)
GNSS global navigation satellite system
GPS Global Positioning System (U.S.A.)
ICD interface control document
ICG International Committee on Global Navigation Satellite Systems (UN)
IMU inertial measurement unit
LEO low Earth orbit
LiDAR light detection and ranging or laser imaging detection and ranging
LBS location-based service
PPP precise point positioning
QZSS Quasi-Zenith Satellite System (Japan)
RTCM Radio Technical Commission for Maritime Services
RTK real-time kinematic GNSS positioning
SBAS satellite based augmentation system
SSV space service volume
TTFF time to first fix
UAS unmanned aircraft system
5 Code system
5.1 Positioning
5.1.1 General
The GNSS receiver class codes shall be specified as shown as Table 1. These codes are used not only
satellite positioning, but also in satellite radionavigation.
Table 1 — Codes on positioning
Function Ranging Augmentation or correction
C10 No augmentation
C11 DGNSS OSR correction
Single frequency
C1
ranging
SSR correction without
C16
Code-based
fixed phase-range
C
C20 No augmentation
positioning
C25 DFMC SBAS
Dual or multiple
C2
frequency ranging
SSR correction without
C26
fixed phase-range
Input: SSR correction
P0 No ranging P06
Output: OSR correction
Phase-range
P11 OSR correction
Single frequency
P P1
ranging
positioning P16 SSR correction
P21 OSR correction
Dual or multiple
P2
frequency ranging
P26 SSR correction
Continuation of C10a C10 with authentication
Table 1
Continuation of C1 C11a C11 with authentication
C16a C16 with authentication
C20a C20 with authentication
Continuation of C1 C25a C25 with authentication
C26a C26 with authentication
Continuation of P0 P06a P06 with authentication
P11a P11 with authentication
Continuation of P1
P16a P16 with authentication
P21a P21 with authentication
Continuation of P2
P26a P26 with authentication
Corrections have two types: OSR and SSR. SSR covers wider area than OSR. Further, these services shall
provide integrity information.
OSR is a representation of correction in observation form such as pseudorange. It is represented as a
factor in observation space, which is a mathematical vector space.
On the other hand, SSR is another representation of correction as error factors, such as satellite clock
and orbit errors, signal bias, ionospheric error, which is a state in a state space, a mathematical vector
space.
In this document, t
...