Appendix B B-14 B.4.8.7 TSO-C196/196a.
Means of compliance for this TSO are defined in RTCA/DO-316, section 2.1.2.6 (also refer to section 1.7.1 and appendix H of RTCA/DO-316).
B.4.9 Geometric Altitude.
All GNSS position sources must output a geometric altitude. Geometric altitude for ADS-B purposes is the height above the WGS-84 ellipsoid (that is, it is not MSL).
We recommend that the GNSS position source output geometric altitude as Height-Above-Ellipsoid (HAE). Some GNSS position sources provide Height-Above-Geoid (HAG) instead of HAE. The position source manufacturer must provide data on whether the position source outputs HAE or HAG.
B.4.9.1 TSO-C129.
Means of compliance for this TSO require GNSS manufacturers to provide data to substantiate the output of HAE. The data produced to substantiate vertical position accuracy pursuant to the test described in AC 20-138(), appendix 4, section A4-10 is sufficient. For GPS equipment that outputs other altitude measures, the installation instructions must specify a deterministic method to perform conversion to HAE.
B.4.9.2 TSO-C129a.
Means of compliance for this TSO require GNSS manufacturers to provide data to substantiate the output of HAE. The data produced to substantiate vertical position accuracy pursuant to the test described in AC 20-138(), appendix 4, section A4-10 is sufficient. For GPS equipment that outputs other altitude measures, the installation instructions must specify a deterministic method to perform conversion to HAE.
B.4.9.3 TSO-C145/146 Rev a Class 1.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy pursuant to the test described in AC 20-138(), appendix 4, section A4-10 is sufficient.
B.4.9.4 TSO-C145/146 Rev a Class 2/3.
For Class 2 equipment, the means of compliance for this TSO require GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy pursuant to the test described in AC 20-138(), appendix 4, section A4-10 is sufficient. Class 3 equipment complies with the ADS-B geometric altitude requirement pursuant to RTCA/DO-229C, section 2.1.5.8.
Appendix B B-15 B.4.9.5 TSO-C145/146 Rev b/c/d Class 1.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy pursuant to the test described in AC 20-138(), appendix 4, section A4-10 is sufficient.
B.4.9.6 TSO-C145/146 Rev b/c/d Class 2/3.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy pursuant to the test described in AC 20-138(), appendix 4, section A4-10 is sufficient.
B.4.9.7 TSO-C196/196a.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy pursuant to the test described in AC 20-138(), appendix 4, section A4-10 is sufficient.
B.4.10 Update Rate.
The position source must output a new position at a minimum of once per second.
Faster position update rates reduce latency of the transmitted position and are encouraged.
B.4.10.1 TSO-C129.
Means of compliance for TSO-C129 are described in RTCA/DO-208 change 1, section 2.1.11 for displays. This requirement is modified by TSO-C129 section (a)(3)(vi) for navigation data used for display in Class A equipment. Class B and Class C equipment are modified by sections (a)(4)(v) and section (a)(5)(v) respectively.
B.4.10.2 TSO-C129a.
Means of compliance for TSO-C129a are described in RTCA/DO-208 change 1, section 2.1.11 for displays. This requirement is modified by TSO-C129a, section (a)(3)(vi) for navigation data used for display in Class A equipment. Class B and Class C equipment are modified by sections (a)(4)(v) and (a)(5)(v) respectively.
B.4.10.3 TSO-C145/146 Rev a Class 1.
Means of compliance for this TSO are defined in RTCA/DO-229C, section 2.1.2.6.1.
B.4.10.4 TSO-C145/146 Rev a Class 2.
Means of compliance for this TSO are defined in RTCA/DO-229C, sections 2.1.2.6.1 and 2.1.5.8.1.
Appendix B B-16 B.4.10.5 TSO-C145/146 Rev b/c/d Class 1.
Means of compliance for this TSO are defined in RTCA/DO-229D, section 2.1.2.6.1.
B.4.10.6 TSO-C145/146 Rev b/c/d Class 2/3.
Means of compliance for this TSO are defined in RTCA/DO-229D, sections 2.1.2.6.1 and 2.1.5.8.1.
B.4.10.7 TSO-C196/196a.
Means of compliance for this TSO are defined in RTCA/DO-316, section 2.1.2.6.1 B.4.11 Horizontal Velocity.
The position source must output north/south and east/west velocities. It is recommended the position source also output the velocity in a ground speed and track angle format.
Note: The intent is to output position, velocity, and quality metrics in a consistent manner for time of applicability (refer to RTCA/DO-229D, sections 2.1.2.6 and
2.1.2.6.2).
B.4.11.1 TSO-C129.
Means of compliance for this TSO require GNSS manufacturers to perform the velocity test in AC 20-138(), appendix 4 and provide information substantiating the data is output.
B.4.11.2 TSO-C129a.
Means of compliance for this TSO require GNSS manufacturers to perform the velocity test in AC 20-138(), appendix 4 and provide information substantiating the data is output.
B.4.11.3 TSO-C145/146 Rev a Class 1.
Means of compliance for this TSO are defined in RTCA/DO-229C, section 2.1.2.6 along with the test defined in AC 20-138(), appendix 4.
B.4.11.4 TSO-C145/146 Rev a Class 2/3.
Means of compliance for this TSO are defined in RTCA/DO-229C, section 2.1.2.6 along with the test defined in AC 20-138(), appendix 4.
B.4.11.5 TSO-C145/146 Rev b/c/d Class 1.
Means of compliance for this TSO are defined in RTCA/DO-229D, section 2.1.2.6. The TSO requirement is only to output velocity, but there is no accuracy requirement. Satisfying this ADS-B requirement means the GNSS manufacturer must also comply with the horizontal velocity accuracy requirements and tests described in AC 20-138(), appendix 4.
Appendix B B-17 B.4.11.6 TSO-C145/146 Rev b/c/d Class 2/3.
Means of compliance for this TSO are defined in RTCA/DO-229D, section 2.1.2.6. The TSO requirement is only to output velocity, but there is no accuracy requirement. Satisfying this ADS-B requirement means the GNSS manufacturer must also comply with the horizontal velocity accuracy requirements and tests described in AC 20-138(), appendix 4.
B.4.11.7 TSO-C196/196a.
Means of compliance for this TSO are defined in RTCA/DO-316, section 2.1.2.6. The TSO requirement is only to output velocity, but there is no accuracy requirement. Satisfying this ADS-B requirement means the GNSS manufacturer must also comply with the horizontal velocity accuracy requirements and tests described in AC 20-138(), appendix 4.
Note: The velocity test found in AC 20-138() is also defined in section
2.3.6.4 of RTCA/DO-316.
B.4.12 Ground Speed.
It is recommended that the position source output ground speed. GNSS manufacturers choosing to output ground speed may show compliance as described below for the appropriate TSO.
B.4.12.1 TSO-C129.
Means of compliance for this TSO require GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (that is, in a ground speed format versus north/east velocity format) and the protocols used.
B.4.12.2 TSO-C129a.
Means of compliance for this TSO require GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (that is, in a ground speed format versus north/east velocity format) and the protocols used.
B.4.12.3 TSO-C145/146 Rev a Class 1.
The Gamma equipment requirements outlined in RTCA/DO-229C, section 2.2.1.4.10 for the display resolution of ground speed are insufficient to show ADS-B compliance. A recommendation for GNSS manufacturers on label 103 and label 112 can be found in RTCA/DO-229D, appendix H. Additional means of compliance for TSO-C145/146 Rev a Class 1 require GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (that is, in a ground speed format versus north/east velocity format) and the protocols used.
Appendix B B-18 B.4.12.4 TSO-C145/146 Rev a Class 2/3.
The Gamma equipment requirements outlined in RTCA/DO-229C, section 2.2.1.4.10 for the display resolution of ground speed are insufficient to show ADS-B compliance. A recommendation for GNSS manufacturers on label 103 and label 112 can be found in RTCA/DO-229D, appendix H. Additional means of compliance for TSO-C145/146 Rev a Class 2/3 require GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (that is, in a ground speed format versus north/east velocity format) and the protocols used.
B.4.12.5 TSO-C145/146 Rev b/c/d Class 1.
Gamma-1 equipment requirements outlined in RTCA/DO-229D, section 2.2.1.4.10 for the display resolution of ground speed are insufficient to show ADS-B compliance. A recommendation for GNSS manufacturers on label 103 and label 112 can be found in RTCA/DO-229D, appendix H. Additional means of compliance for TSO-C145/146 Rev b/c/d Class 1 require GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (that is, in a ground speed format versus north/east velocity format) and the protocols used.
B.4.12.6 TSO-C145/146 Rev b/c/d Class 2/3.
Gamma-2 and Gamma-3 equipment requirements outlined in RTCA/DO-229D, section 2.2.1.4.10 for the display resolution of ground speed are insufficient to show ADS-B compliance. A recommendation for GNSS manufacturers on label 103 and label 112 can be found in RTCA/DO-229D, appendix H. Additional means of compliance for TSO-C145/146 Rev b/c/d Class 2/3 require GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (that is, in a ground speed format versus north/east velocity format) and the protocols used.
B.4.12.7 TSO-C196/196a.
Means of compliance for this TSO require GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (that is, in a ground speed format versus north/east velocity format) and the protocols used. A recommendation for GNSS manufacturers on label 103 and label 112 can be found in RTCA/DO-316, appendix H.
B.4.13 Time of Applicability.
The GNSS equipment must output a time of applicability.
Note: The intent is to output position, velocity, and HFOM with a consistent time of applicability (refer to RTCA/DO-229D, sections 2.1.2.6 and 2.1.2.6.2).
Appendix B B-19 B.4.13.1 TSO-C129.
Means of compliance for this TSO require GNSS manufacturers to use a manufacturer-defined test and/or analysis to determine the latency between the time satellite measurements are collated for processing and the time the equipment calculates a filtered (impulse response) position solution. For example; the receiver does not make observations at a single moment in time but instead staggers them, perhaps to reduce throughput.
In that case, the observations would need to be extrapolated to a common moment. There are many extrapolation methods but some use filtering that may induce latency. This would need to be addressed in the latency analysis. Since there are filters involved, measuring the impulse response may be one way of observing this delay. Furthermore, as another example; a receiver uses a Costas filter that has a specific bandwidth as part of the tracking loop. That bandwidth constrains the speed at which a dynamic maneuver will propagate through the tracking loop and thus to the resulting position. Again, measuring the impulse response of the Costas loop would provide insight into delay that would be observed when installed. Bearing this in mind, the equipment must meet a 500- millisecond TOM-to-time-of-applicability requirement and account for the impulse response of the position solution.
B.4.13.2 TSO-C129a.
Means of compliance for this TSO require GNSS manufacturers to use a manufacturer-defined test and/or analysis to determine the latency between the time satellite measurements are collated for processing and the time the equipment calculates a filtered (impulse response) position solution. The equipment must meet a 500-millisecond TOM-to-time-ofapplicability requirement and account for the impulse response of the position solution.
B.4.13.3 TSO-C145/146 Rev a Class 1.
Means of compliance for this TSO are defined in RTCA/DO-229C sections 2.1.2.6 and 2.1.2.6.2.
B.4.13.4 TSO-C145/146 Rev a Class 2/3.
Means of compliance for this TSO are defined in RTCA/DO-229C, sections 2.1.2.6, 2.1.2.6.2, and 2.1.5.8.2.
B.4.13.5 TSO-C145/146 Rev b/c/d Class 1.
Means of compliance for this TSO are defined in RTCA/DO-229D, sections 2.1.2.6 and 2.1.2.6.2.
B.4.13.6 TSO-C145/146 Rev b/c/d Class 2/3.
Means of compliance for this TSO are defined in RTCA/DO-229D, sections 2.1.2.6, 2.1.2.6.2, and 2.1.5.8.2.
Appendix B B-20 B.4.13.7 TSO-C196/196a.
Means of compliance for this TSO are defined in RTCA/DO-316, sections 2.1.2.6 and 2.1.2.6.2.
B.4.14 Velocity Accuracy.
The GNSS position source manufacturer must provide design data to assist the installer in setting the NACV. Scaling the reported GNSS position accuracy (HFOM and VFOM) is not an acceptable means to determine NACV.
B.4.14.1 NACV = 1.
For installations intending to support NACV = 1, the GNSS manufacturer must perform the velocity tests in AC 20-138D, appendix 4, section A4-1 through A4-8 associated with NACV = 1. The GNSS manufacturer must indicate that the equipment satisfies the requirements for NACV =1 in the installation instructions for the ADS-B integration.
B.4.14.2 NACV = 2.
For installations intending to support NACV = 2, the GNSS manufacturer must perform the velocity tests in AC 20-138D, appendix 4, sections A4-1 through A4-9 associated with NACV = 1 and NACV = 2. The GNSS manufacturer must present substantiation data that the equipment dynamically outputs HFOMv and VFOMv (refer to AC 20-138(), appendix 4, sections A4-5 and A4-8) and that the equipment velocity and accuracy outputs have passed the velocity tests associated with NACV = 1 and NACV = 2. The GNSS manufacturer must indicate that the equipment satisfies the requirements for NACV = 2 in the installation instructions for the ADS-B integration.
B.4.14.3 NACV = 3 or 4.
No standard for performance has been developed to support NACv = 3 or NACV = 4. A NACV = 3 or NACV = 4 should not be set based on GNSS velocity accuracy unless you can demonstrate to the FAA that the error contributions have been adequately modeled to meet those levels of performance.
B.4.14.4 TSO-C129.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data based on the NACV =1 and NACV = 2 test as appropriate and document the NACV in the installation instructions for the ADS-B integration. Refer to AC 20-138(), appendix 4, section A4- 2d(3) for additional guidance relative to using the noise environment in RTCA/DO-235B for the velocity tests.
B.4.14.5 TSO-C129a.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data based on the NACV =1 and NACV = 2 test
Appendix B B-21 as appropriate and document the NACV in the installation instructions for the ADS-B integration. Refer to AC 20-138() appendix 4, section A4- 2d(3) for additional guidance relative to using the noise environment in RTCA/DO-235() for the velocity tests.
B.4.14.6 TSO-C145/146 Rev a Class 1.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data based on the NACV =1 and NACV = 2 test as appropriate and document the NACV in the installation instructions for the ADS-B integration.
B.4.14.7 TSO-C145/146 Rev a Class 2/3.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data based on the NACV =1 and NACV = 2 test as appropriate and document the NACV in the installation instructions for the ADS-B integration.
B.4.14.8 TSO-C145/146 Rev b/c/d Class 1.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data based on the NACV =1 and NACV = 2 test as appropriate and document the NACV in the installation instructions for the ADS-B integration.
B.4.14.9 TSO-C145/146 Rev b/c/d Class 2/3.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data based on the NACV =1 and NACV = 2 test as appropriate and document the NACV in the installation instructions for the ADS-B integration.
B.4.14.10 TSO-C196/196a.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data based on the NACV =1 and NACV = 2 test as appropriate and document the NACV in the installation instructions for the ADS-B integration.
B.4.15 Vertical Position Accuracy.
The GNSS should output vertical position accuracy. The vertical accuracy should specify a 95-percent probability bound on the reported vertical position. No revisions of TSO-C129 or TSO-C196 have vertical accuracy or integrity requirements, and TSO-C145 /146 only has vertical accuracy requirements for certain approach modes.
None of the GNSS TSOs have a requirement to continuously output the vertical position accuracy data. If vertical position accuracy is output, it must have been qualified during design approval of the position source.
Appendix B B-22 B.4.15.1 TSO-C129.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in AC 20-138(), appendix 4, section A4-10.
B.4.15.2 TSO-C129a.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in AC 20-138(), appendix 4, section A4-10.
B.4.15.3 TSO-C145/146 Rev a Class 1.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in AC 20-138(), appendix 4, section A4-10.
B.4.15.4 TSO-C145/146 Rev a Class 2.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in AC 20-138(), appendix 4, section A4-10.
B.4.15.5 TSO-C145/146 Rev b/c/d Class 1.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in AC 20-138(), appendix 4, section A4-10.
B.4.15.6 TSO-C145/146 Rev b/c/d Class 2/3.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in AC 20-138(), appendix 4, section A4-10.
B.4.15.7 TSO-C196/196a.
Means of compliance for this TSO require GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in AC 20-138(), appendix 4, section A4-10.
B.4.16 Mode Output.
If interpretation of the integrity output of the position source can change due to a change in the position source mode, the position source must have a way of communicating that change of mode to the ADS-B equipment. Additionally, the position source manufacturer should provide a description of the modes and a description of how the position source outputs the mode indication.
B.4.16.1 TSO-C129.
Means of compliance for this TSO require GNSS manufacturers to provide installation instructions describing the modes available (if
Appendix B B-23 affecting interpretation of integrity output) and how the position source outputs the mode indication (refer to Position Integrity Limits, section paragraph B.4.7, of this appendix).
B.4.16.2 TSO-C129a.
Means of compliance for this TSO require GNSS manufacturers to provide installation instructions describing the modes available (if affecting interpretation of integrity output) and how the position source outputs the mode indication (refer to Position Integrity Limits, paragraph B.4.7, of this appendix).
B.4.16.3 TSO-C145/146 Rev a Class 1.
Means of compliance for this TSO require GNSS manufacturers to provide installation instructions describing the modes available (if affecting interpretation of integrity output) and how the position source outputs the mode indication (refer to Position Integrity Limits, paragraph B.4.7, of this appendix).
B.4.16.4 TSO-C145/146 Rev a Class 2.
Means of compliance for this TSO require GNSS manufacturers to provide installation instructions describing the modes available (if affecting interpretation of integrity output) and how the position source outputs the mode indication (refer to Position Integrity Limits, paragraph B.4.7, of this appendix).
B.4.16.5 TSO-C145/146 Rev b/c/d Class 1.
Means of compliance for this TSO require GNSS manufacturers to provide installation instructions describing the modes available (if affecting interpretation of integrity output) and how the position source outputs the mode indication (refer to Position Integrity Limits, paragraph B.4.7, of this appendix).
B.4.16.6 TSO-C145/146 Rev b/c/d Class 2/3.
Means of compliance for this TSO require GNSS manufacturers to provide installation instructions describing the modes available (if affecting interpretation of integrity output) and how the position source outputs the mode indication (refer to Position Integrity Limits, paragraph B.4.7, of this appendix).
B.4.16.7 TSO-C196/196a.
Means of compliance for this TSO require GNSS manufacturers to provide installation instructions describing the modes available (if affecting interpretation of integrity output) and how the position source outputs the mode indication (refer to Position Integrity Limits, paragraph B.4.7, of this appendix).
Appendix B B-24 B.4.17 Approach Mode Integrity.
SBAS equipment certified under any revision of TSO-C145 or TSO-C146 is required to have several modes of operation depending on the availability of augmentation. For example, when operating in an augmented mode intended for LPV approach guidance, the position source may determine HPL based on a lateral error versus a horizontal error and an exposure time based on the duration of the approach versus flight hour (refer to RTCA/DO-229D, appendix J). If the position source outputs the HPL on lateral error and approach exposure time, it is possible that the ADS-B transmitter would need to inflate the HPL by 3 percent in approach modes to ensure the integrity is appropriately bounded. GBAS equipment is required to comply with the GNSS or SBAS requirements for the output of position data. This is an integration issue between the GPS and ADS-B transmitter. The position source manufacturer must provide information to the system integrator to determine if the integrity output needs to be scaled (that is, by applying an inflation factor). Although we do not address the interface of a GBAS differentially-corrected position source in this AC, it will have similar considerations in approach modes as SBAS.
B.4.17.1 TSO-C129.
This is not applicable to this TSO as no HPL scaling is applied.
B.4.17.2 TSO-C129a.
This is not applicable to this TSO as no HPL scaling is applied.
B.4.17.3 TSO-C145/146 Rev a Class 1.
Means of compliance for this TSO are defined in RTCA/DO-229C, sections 2.1.1.13.1 and 2.1.3.2.2.
B.4.17.4 TSO-C145/146 Rev a Class 2/3.
Means of compliance for this TSO are defined in RTCA/DO-229C, sections 2.1.1.13.1, 2.1.3.2.2, 2.1.4.2.2, and 2.1.5.2.2.
B.4.17.5 TSO-C145/146 Rev b/c/d Class 1.
Means of compliance for this TSO are defined in RTCA/DO-229D, sections 2.1.1.13.1 and 2.1.3.2.2.
B.4.17.6 TSO-C145/146 Rev b/c/d Class 2/3.
Means of compliance for this TSO are defined in RTCA/DO-229D, sections 2.1.1.13.1, 2.1.3.2.2, 2.1.4.2.2, and 2.1.5.2.2.
B.4.17.7 TSO-C196/196a.
This is not applicable to this TSO as no HPL scaling is applied.
B.4.18 Track Angle Validity.
GNSS position sources can provide a track angle; however, the GNSS track angle may become invalid below a certain velocity. Optimally, the position source should either
Appendix B B-25 invalidate or remove the track angle when it is no longer valid. If the position source does not invalidate the track angle or remove the track angle when it is potentially invalid, the position source manufacturer must provide information on velocity limitations for GNSS track angle.
Note: The interference levels used to demonstrate velocity accuracy compliance can be used for track angle validity as well.
B.4.18.1 TSO-C129.
Means of compliance for TSO-C129 require GNSS manufacturers to use the test environment and guidance defined in AC 20-138(), appendix 4, section 4-12. It is recommended that manufacturers use RTCA/DO-229D, appendix H for outputting track angle (ARINC 743 all revisions, label 103) for those using ARINC 429 characteristics.
B.4.18.2 TSO-C129a.
Means of compliance for TSO-C129a require GNSS manufacturers to use the test environment and guidance defined in AC 20-138(), appendix 4, section 4-12. It is recommended that manufacturers use RTCA/DO-229D, appendix H for outputting track angle (ARINC 743 all revisions, label 103) for those using ARINC 429 characteristics.
B.4.18.3 TSO-C145/146 Rev a Class 1.
Means of compliance for TSO-C145/146 Rev a Class 1 require GNSS manufacturers to use the test environment and guidance defined in AC 20-138(), appendix 4, section 4-12. It is recommended that manufacturers use RTCA/DO-229C, appendix H for outputting track angle (ARINC 743 all revisions, label 103) for those using ARINC 429 characteristics.
B.4.18.4 TSO-C145/146 Rev a Class 2/3.
Means of compliance for TSO-C145/146 Rev a Class 2/3 require GNSS manufacturers to use the test environment and guidance defined in AC 20-138(), appendix 4, section 4-12. It is recommended that manufacturers use RTCA/DO-229C, appendix H for outputting track angle (ARINC 743 all revisions, label 103) for those using ARINC 429 characteristics.
B.4.18.5 TSO-C145/146 Rev b/c/d Class 1.
Means of compliance for TSO-C145/146 Rev b/c/d Class 1 require GNSS manufacturers to use the test environment and guidance defined in AC 20-138(), appendix 4, section 4-12. It is recommended that manufacturers use RTCA/DO-229D, appendix H for outputting track angle (ARINC 743 all revisions, label 103) for those using ARINC 429 characteristics.