ISO 18423-2015 PDF

Full title and description

Space data and information transfer systems — Pseudo‑Noise (PN) Ranging Systems. This International Standard specifies the PN ranging signal structures and techniques for both transparent and regenerative PN ranging, covering PN code components and generation, on‑board spacecraft processing (regenerative and transparent), ground‑station processing, and uplink/downlink signal modulation. It is a recommended standard intended to enable interoperable PN‑based two‑way ranging between spacecraft and ground stations.

Abstract

ISO 18423:2015 defines the structure and processing requirements for pseudo‑noise (PN) ranging systems used in space missions. The standard describes code families and generation rules, spacecraft regenerative and transparent processing modes, ground station receiver and transmitter processing, and modulation considerations for uplink and downlink. It does not prescribe specific product implementations, service‑interface implementations, or operational/configuration management activities.

General information

• Status: Published (International Standard, confirmed).
• Publication date: August 2015 (Edition 2, 2015).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 49.140 (Space systems and operations).
• Edition / version: Edition 2 (2015).
• Number of pages: 28.

Technical committee: ISO/TC 20/SC 13. The publication was last reviewed and confirmed in 2023, so this edition remains the current ISO version.

Scope

ISO 18423:2015 applies to PN (pseudo‑noise) two‑way ranging systems for spacecraft and ground stations where PN ranging is used to measure round‑trip light time (range). The scope includes definitions and specifications for PN component sequences and full PN code construction, code generation rules, spacecraft transparent and regenerative processing requirements, ground‑station processing and performance, and uplink/downlink modulation and signal structure. The standard explicitly excludes specification of particular product implementations, internal service‑interface implementations, and management/configuration procedures for systems.

Key topics and requirements

• PN code families and component sequence construction (chip rates, component codes, epoching).
• Rules for PN code generation and timing (synchronization and epoch alignment).
• Definitions and requirements for transparent (turn‑around) and regenerative ranging modes.
• On‑board processing behaviour for regenerative transponders and requirements for coherent/phase‑coherent operation.
• Ground station acquisition, tracking and measurement performance expectations (acquisition probability, SNR regimes, Doppler/timing tolerances).
• Uplink and downlink signal modulation considerations and modulation index requirements for reliable ranging.
• Interoperability guidelines to support cross‑support between agencies and different implementations.

Typical use and users

Primary users are spacecraft RF and navigation engineers, ground segment designers, mission operations and tracking teams, spacecraft manufacturers, and test laboratories. Typical uses include specifying spacecraft and ground‑station ranging subsystems, designing PN code generation and processing chains, establishing cross‑support agreements between agencies, and validating ranging performance during integration and mission operations.

Related standards

ISO 18423:2015 is aligned with and derived from CCSDS recommendations for PN ranging (CCSDS PN‑ranging documents such as CCSDS 414.x series). It is related to other space‑link and tracking standards produced by CCSDS and national/international space standards (for example, ECSS and CCSDS tracking/ranging documents) that address complementary aspects of ranging, Doppler tracking and link modulation. These related documents are commonly referenced when implementing interoperable ranging systems.

Keywords

Pseudo‑Noise (PN) ranging; PN code; regenerative ranging; transparent (turn‑around) ranging; spacecraft ranging; ground station processing; chip rate; two‑way range; CCSDS; space data and information transfer.

FAQ

Q: What is this standard?

A: ISO 18423:2015 is an International Standard that specifies pseudo‑noise (PN) two‑way ranging system structures and processing requirements for space missions, covering PN code generation, spacecraft processing modes, and ground station processing.

Q: What does it cover?

A: It covers PN code families and generation rules, transparent and regenerative ranging modes, on‑board and ground‑station processing requirements, and uplink/downlink modulation and signal‑structure considerations; it does not mandate specific product implementations or operational management procedures.

Q: Who typically uses it?

A: Spacecraft systems and RF/telemetry engineers, navigation and tracking teams, ground segment designers, mission operations staff, space agencies and contractors coordinating interoperable ranging capability.

Q: Is it current or superseded?

A: Edition 2 (ISO 18423:2015) is the current ISO edition and was reviewed and confirmed in 2023. Users should check for any future reviews or revisions after that confirmation date when planning long‑term projects.

Q: Is it part of a series?

A: It is part of the ISO activity for space data and information transfer systems (ISO/TC 20/SC 13) and corresponds to CCSDS PN‑ranging recommendations (the CCSDS 414.x series), so it is commonly used alongside other CCSDS and ECSS standards addressing space links, modulation and tracking.

Q: What are the key keywords?

A: Key keywords are PN ranging, pseudo‑noise, regenerative ranging, transparent ranging, PN code, chip rate, spacecraft ranging, ground station, two‑way range, CCSDS.