EUROCAE ED-114A PDF

PURPOSE AND SCOPE

This document contains Minimum Operational Performance Specification (MOPS) for a Ground Based Augmentation System (GBAS) Ground Subsystem, as part of a Global Navigation Satellite System (GNSS) to support Category I precision approach and landing based on GPS L1.

This MOPS is designed to ensure that GBAS Ground Subsystems certified against it will be compatible with the ICAO Standards and Recommended Practices.

This MOPS contains requirements for GBAS Ground Subsystems that optionally support:

• GBAS positioning service

• VHF data broadcast authentication

• Broadcast of Type 5 message, "Predicted Ranging Source Availability"

It does not include requirements for:

• Use of GLONASS and SBAS ranging sources

• VHF data broadcast with elliptical (GBAS/E) polarization

• Ground-based Regional Augmentation System (GRAS)

Chapter 1 of this document provides the information required to understand the need for the equipment characteristics and tests defined in the remaining chapters. It describes typical equipment applications and operational objectives, and it forms the basis for the performance criteria stated in Chapter 2 to Chapter 4. Definitions essential to the proper understanding of this document are also provided in Chapter 1.

Chapter 2 contains general design requirements including system/subsystem performance allocations, GBAS ground equipment maintainability, hardware and software design assurance, personnel safety and environmental test conditions.

Chapter 3 contains the specific technical requirements of the GBAS ground equipment such as coverage volume, operating modes with control and status, data link characteristics and executive monitoring.

Chapter 4 prescribes the issues to consider during the siting of GBAS ground equipment, such as location, installation, multipath and interference.

Chapter 5 describes recommended test procedures for demonstrating compliance with Chapters 2, 3 and 4. As the measured values of equipment performance characteristics may be a function of the method of measurement, standard test conditions and methods of testing are recommended in this chapter.

Appendix A provides guidance on the broadcast message format and coding.

Appendix B provides guidance on the rationale behind the VDB power density requirements given in Chapter 3.

Appendix C provides guidance in relation to Continuity of Service and includes an example of continuity risk allocation.

Appendix D provides the Integrity risk allocation. Appendix E provides information on the standard interference mask.

Appendix F provides information on the use of multiple transmit antennas to improve the coverage of the VDB.

Appendix G provides guidance on the objectives of Signal Quality Monitoring, the use of threat models and typical monitoring concepts.

Appendix H provides information on the testing used during selection of a suitable site for the GBAS Ground subsystem.

Appendix I provides guidance on the use of the GBAS Positioning Service.

Appendix J provides guidance on the optional data recording function.

Appendix K provides an example of message encoding.

Appendix L provides guidance on ionosphere anomaly mitigation.

Appendix M contains the FAS data file format description.

Appendix N contains the traceability matrix to ICAO GBAS SARPs.

In this document, the use of the word "Shall" indicates a mandated criterion; i.e. compliance with the particular procedure or specification is mandatory and no alternative may be applied.

The use of the word "Should" (and phrases such as "It is recommended that...", etc.) indicate that although the procedure or criterion is regarded as the preferred option, alternative procedures, specifications or criteria may be applied, provided that the manufacturer, installer or tester can provide information or data to adequately support and justify the alternative.