PURPOSE AND SCOPE

This document contains Minimum Operational Performance Standards for GPS / Galileo / SBAS dual-frequency L1/L5 airborne equipment. This standard specifies the minimum performance expected from GPS / Galileo / SBAS dual-frequency L1/L5 airborne equipment.

This initial issue is focused on equipment processing signals broadcast by GPS satellites, Galileo satellites and geostationary SBAS satellites providing correction and integrity data, but no ranging data. It is meant to support prototyping activities linked to the SBAS L5-provided integrity monitoring capability with a Class Beta-like equipment, then evolve into a complete MOPS enabling the development of certified avionics.

The next issue – Revision A – will address Class Delta specific requirements. The development of DFMC SBAS navigator requirements supporting class Gamma equipment is out of EUROCAE Working Group 62 current scope.

The next issue will also incorporate the requirements from RTCA/DO-229E and a dedicated appendix tracking the differences between DO-229E and ED-259. For the initial issue, GPS L1 and SBAS L1 signals are considered to be processed as per DO-229E, and temporary requirements tagged [REQ-000] are used to reference DO-229E.

The next issue will adress the L1 and L5 interference levels according to the updates of RTCA/DO-235() and DO-292() documents.

The reader is invited to consider sections related to FDE-provided integrity monitoring as preliminary requirements.

The reader should also note that the definition of the environmental tests and test procedures is not in the scope of this initial issue, and the corresponding chapters will be complemented in the next issue.

Compliance with this standard is recommended as one means of assuring that the equipment will perform its intended functions satisfactorily under all conditions normally encountered in routine aeronautical operation.

This MOPS is designed to ensure that equipment compliant to it will get the necessary regulatory approval (this is generally facilitated by the recognition of such standard by the relevant authorities as an acceptable means of compliance with the applicable regulations).

The document is structured as follows:

Chapter 1 provides 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 is the basis for the performance criteria stated in Chapter 2 to Chapter 4. Definitions essential to proper understanding of this document are also provided in Chapter 1.

Chapter 2 contains general design requirements.

Chapter 3 contains the minimum performance specification for the equipment, defining performance under standard operating conditions.

Chapter 4 will prescribe the environmental test conditions, which provide a laboratory means of determining the overall performance characteristics of the equipment under conditions representative of those, which may be encountered in actual operations.

Chapter 5 will describe recommended test procedures for demonstrating compliance with Chapter 3 and Chapter 4.

Chapter 6 will specify the performance required of the installed equipment. Ground and flight tests for the installed equipment are included when performance cannot be adequately determined through testing under standard test conditions.

Chapter 7 will list some considerations for Aircraft Operational Performance Characteristics.

Appendix A is normative: it contains the SBAS L5 signal specification.

Appendix B is normative: it contains GPS and Galileo assumptions.

Appendix C is normative and will describe the interference environment.

Appendix D is normative: it describes the baseline weighted algorithm for navigation and approach when using SBAS L5-provided integrity monitoring. It includes two example means of implementing the navigation system error algorithm.

Appendix E is normative: it describes the required methods of calculating SBAS L5-based protection levels, based upon the data in the SBAS L5 message.

Appendix F describes a method of Fault Detection monitoring associated with the SBAS L5-based integrity monitoring.

Appendix G contains process flow diagrams intended to be an example of the computation and logic flow that meets requirements for the possible operational modes. It is not intended to show all possible implementations. Instead, a representative implementation is shown with reference to the applicable requirements.

Appendix H is normative: it describes the parameters broadcast by GPS and Galileo satellites that cannot be used by the equipment.

Appendix I provides additional elements on SBAS L5 signals for SBAS ranging and for non-geostationary satellites. For the current issue of this document, the material provided in this appendix is for information only.

Appendix J is normative and describes the troposphere correction model to apply with SBAS L5-provided integrity monitoring.

Operational performance standards for functions or components that refer to equipment capabilities that exceed the stated minimum requirements are identified as optional features.

The word “equipment” as used in this document includes all components and units necessary for the system to properly perform its intended function(s).