Interface Control Documents

Updated February 6, 2025

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Historic ICDs

The communication boundaries between the Global Positioning System and other systems, as well as within the GPS itself, are known as interfaces. Interface Control Documents (ICDs) are the formal means of establishing, defining, and controlling interfaces and for documenting detailed interface design information for the GPS program.

Interface Specifications (ISs) are specific types of ICDs that only need approval from one government office or agency. The procedure and process for development, control, and maintenance is the same for ICDs and ISs.

New ICD Revisions in Development

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Current ICDs in Effect

ICD Name Revision Date Description

IS-GPS-200 N
View PDF (3.2 MB) 08/22/2022 Defines the requirements related to the interface between the GPS space and user segments for radio frequency link 1 (L1) and link 2 (L2) IRN-003
View PDF (780.3 KB) 01/19/2024 Changes per RFC-00502: 2023 Proposed Changes to the Public Documents IS-GPS-705 J
View PDF (1.7 MB) 08/22/2022 Defines the requirements related to the interface between the GPS space and user segments for radio frequency link 5 (L5) IRN-003
View PDF (467.7 KB) 01/19/2024 Changes per RFC-00502: 2023 Proposed Changes to the Public Documents IS-GPS-800 J
View PDF (4 MB) 08/22/2022 Defines the characteristics of the L1 Civil (L1C) signal transmitted from GPS satellites to navigation receivers on radio frequency link 1 (L1) IRN-003
View PDF (472.1 KB) 01/19/2024 Changes per RFC-00502: 2023 Proposed Changes to the Public Documents ICD-GPS-240 D
View PDF (1.8 MB) 05/21/2021 Defines the functional data transfer interface between the GPS Control Segment (CS) and the GPS user and user-support communities during the Operational Control System (OCS) / Architecture Evolution Plan (AEP) systems era ICD-GPS-870 E
View PDF (1.5 MB) 08/13/2020 Defines the functional data transfer interface between the GPS Next Generation Operational Control System (OCX) and the GPS user and user-support communities; captures the same interface as ICD-GPS-240, but for the OCX era IRN-001
View PDF (1.1 MB) 03/24/2024 Changes per RFC-00477: OCX XML Products for Civil Users

ICD-GPS-153 & Other ICDs

GPS.gov only publishes ICDs approved for public release. If you are seeking an ICD that does not appear on this page, such as ICD-GPS-153, please complete a GPS Technical Library Document Request form and have it signed by a GPS Program representative. The form is available at the U.S. Coast Guard Navigation Center website. Go there

Memo on ICD Compliance

In December 2017, the Air Force issued a memorandum for GPS users and user equipment manufacturers regarding the IODC value selection process and IS-GPS-200H compliance. View memo

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Historic ICDs

Older versions of GPS ICDs, ISs, and Interface Revision Notices (IRNs) remain available for historical reference purposes, but not for new design. View historic ICDs

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Interface Control Working Group

The Interface Control Working Group (ICWG) is a specialized working group comprised of appropriate technical representatives from the interfacing activities and other interested participating organizations.

The ICWG serves as a forum to develop and provide interface requirements, as well as focus on interface detail definition and issues.

ICWG members include representatives from the Space and Missile Systems Center (SMC) of the U.S. Space Force, other government agencies and offices, contractors, and other industry organizations.

ICWGs for documents that are publicly releasable are referred to as Public ICWGs, which are structured the same as the ICWG but with a few additional requirements. The additional requirements include coordinating meetings and documents to the public.

Comments received through the ICWG are adjudicated according to the GPS Technical Baseline Configuration Management Process (TBCMP), which includes an Adjudication Working Group (AWG) and Rough Order of Magnitude (ROM) / Impact Assessment (IA).

For additional information about the ICWG, please contact SMCGPER@us.af.mil.