PURPOSE AND SCOPE

This document contains Minimum Operational Performance Standards (MOPS) for Dual-Frequency Multi-Constellation (DFMC) Satellite-Based Augmentation System (SBAS) airborne equipment. This standard specifies the minimum performance expected from airborne equipment using GPS, Galileo (GAL) and SBAS, for both single-constellation and dual-constellation modes.

This document is meant to support validation of airborne equipment requirements, as well as the development of DFMC SBAS services. This document does not provide specifications for a production approval.

A future release will provide requirements supporting production approval, typically through a new Technical Standard Order (TSO) or European Technical Standard Order (ETSO). It will address the expected functions of future DFMC SBAS equipment including navigation in degraded environment (single-frequency L5 mode), Horizontal Advanced Receiver Autonomous Integrity Monitoring (H-ARAIM) for new signals, and management of the institutional scenarios.

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.

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

The document is structured as follows:

Chapter 1 provides definitions and information required to understand 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 through 4.

Chapter 2 contains general design requirements.

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

Chapter 4 prescribes the environmental test conditions, and provides a laboratory means of determining the overall performance characteristics of the equipment under conditions representative of those which can be encountered in actual operations.

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

Chapter 6 specifies 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 laboratory test conditions.

Chapter 7 lists some considerations for Aircraft Operational Performance Characteristics.

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

Appendix B is normative: it contains the SBAS L1 signal specification.

Appendix C is normative: it specifies the interference environment.

Appendix D is normative: it specifies the baseline weighted algorithm for navigation and approach when using SBAS L1 or SBAS L5-provided integrity monitoring.

Appendix E is normative: it specifies the required methods of calculating SBAS L1 and SBAS L5-based protection levels, based upon the data in the SBAS L1 or SBAS L5 messages.

Appendix F is normative: it contains GPS and Galileo assumptions. It also provides the GPS and Galileo almanacs for testing, and an example of SBAS almanac broadcast in SBAS L1 and SBAS L5 message formats.

Appendix G is normative: it specifies the parameters broadcast by GPS and Galileo satellites that cannot be used by the equipment for the determination of positioning outputs that are compliant with this MOPS.

Appendix H is normative: it specifies the data format to support straight landing approach operations.

Appendix I is normative: it specifies the tropospheric correction model to apply with SBAS L1-provided integrity monitoring for Required Navigation Performance Approach (RNP APCH) to Lateral Navigation / Vertical Navigation (LNAV/VNAV), Localizer Performance without vertical guidance (LP) and Localizer Performance with vertical guidance (LPV) minima operations, and with SBAS L5-provided integrity monitoring.

Appendix J is normative: it specifies the single-frequency ionospheric correction model that can be used as an alternative to the GPS-based model. The model is optional under this MOPS.

Appendix K is reserved for the GPS and Galileo Integrity Support Data (ISD) specifications.

Appendix L is normative: it specifies the requirements when using barometric altimeter to aid GPS Receiver Autonomous Integrity Monitoring / Fault Detection and Exclusion (RAIM/FDE), which is optional under this MOPS.

Appendix M is informative: it contains background materials for testing.

Appendix N is informative: it provides guidance for determining Mean Sea Level (MSL) height from WGS-84 coordinates.

Appendix O is informative: it contains information on the SBAS approach concept developed to handle SBAS operations in a Dual-Frequency Multi-Constellation operational environment.

Appendix P is informative: it provides a typical navigation mode switching flow diagram from the terminal area to the approach. The intent is to aid in understanding the mode switching requirements for Class Gamma equipment.

Appendix Q is informative: it contains SBAS considerations for helicopters.

Appendix R is reserved.

Appendix S is informative: it 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 T is normative: it specifies how to use the tool provided in Supplement 2 (see below) to determine Geostationary Satellite (GEO) bias error in receiver correlator designs. This tool is used to demonstrate receivers meet the GEO bias requirement in this MOPS.

Appendix U is reserved for additional elements on SBAS L5 signals for non-geostationary satellites.

Appendix V is informative: it provides guidance to compute velocity and velocity figure of merit, and to support Automatic Dependent Surveillance - Broadcast (ADS-B) applications.

Appendix W is informative: it describes the classifications for spoofing signals.

Appendix X is reserved for ionosphere scintillation.

Appendix Y is informative: it contains glossary and acronyms.

Appendix Z is informative: it lists substantive items resulting from the OC/FRAC for this version that need to be considered for a future release of this MOPS.

Appendix AA is informative: it lists the members of RTCA SC-159 and EUROCAE WG-62.

The supplement for this document contains six files:

• Supplement 1: “DO-229F to ED-259A DO-401 Traceability.xlsx”. It contains the cross-reference matrix between the DO-229F tagged requirements and untagged recommendations and options, and this MOPS requirements, recommendations and options.

• Supplement 2: “ED-259A DO-401 GEO Bias MATLAB Tool.zip”. It contains the MATLAB scripts to compute the GEO bias errors, as explained in Appendix T.

• Supplement 3.1: “Test_IQ_USFL100_Fc1157_Fs78MHz.mat”. It is the I/Q testing signal file in MATLAB format corresponding to the Low Altitude pulsed interference scenario.

• Supplement 3.2: “Test_IQ_USFL100_Fc1157_Fs78MHz_scaling_factor6.8806e -4.bin”. It is the I/Q testing signal file in binary format corresponding to the Low Altitude pulsed interference scenario.

• Supplement 4.1: “Test_IQ_EUFL400_Fc1157_Fs78MHz.mat”. It is the I/Q testing signal file in MATLAB format corresponding to the High Altitude pulsed interference scenario.

• Supplement 4.2: “Test_IQ_EUFL400_Fc1157_Fs78MHz_scaling_factor6.802e-4.bin”. It is the I/Q testing signal file in binary format corresponding to the High Altitude pulsed interference scenario.

NOTE: For Supplements 3.1, 3.2, 4.1 and 4.2, see Appendix M.5 for further details.