Appendix 2 A2-7 Section J.2.1 defining position integrity (integrity probability is for HPLSBAS only). For additional guidance on an acceptable scaling method, GNSS manufacturers can refer to DO-229D Appendix U Section 4. FDE requirements can be found in 2.1.2.2.2.2.2.
(4) TSO C145/146 Rev a Class 2/3. Means of compliance for this TSO are defined in DO-229C section 2.1.2.2.2.1 for SBAS-based integrity. This requirement references Appendix J, Section J.2.1 defining position integrity (integrity probability is for HPLSBAS only). For additional guidance on an acceptable scaling method, GNSS manufacturers can refer to DO-229D Appendix U Section 4. FDE requirements can be found in section 2.1.2.2.2.2.2.
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO are defined in DO-229D section 2.1.2.2.2.1 for SBAS-based integrity. This requirement references to Appendix J, Section J.3.1 defining position integrity (integrity probability is for HPLSBAS only). For additional guidance on an acceptable scaling method, GNSS manufacturers can refer to DO-229D Appendix U Section 4. FDE requirements can be found in section 2.1.2.2.2.2.2.
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO are defined in DO-229D Section 2.1.2.2.2.1 for SBAS-based integrity. Appendix J, Section J.3.1 provides a background definition for position integrity (integrity probability is for HPLSBAS only). For additional guidance on an acceptable scaling method, GNSS manufacturers can refer to DO-229D Appendix U Section 4. FDE requirements can be found in section 2.1.2.2.2.2.2.
(7) TSO C196/196a. Means of compliance for this TSO are defined in DO-316 section
2.1.2.2.2.2. For additional guidance on an acceptable scaling method, GNSS manufacturers can refer to DO-316 Appendix U Section 4.
f. Integrity fault alerts. GNSS position source manufacturers must provide design data on the maximum time the position source can take to indicate an integrity fault. If the fault indication is mode specific, data on all modes must be included. It is recommended that the indication of an integrity fault be provided within 8 seconds across all modes. All revisions of TSO-C145, TSO-C146, and TSO-C196 GNSS equipment meet this requirement. No revisions of TSO-C129 GNSS equipment meet this requirement without meeting further qualifications outlined below. ARINC characteristic 743A-5, GNSS Sensor, dated May, 2009, compliant receivers represent the condition where a satellite fault has been detected but the receiver was unable to exclude the faulted satellite by setting bit 11 of label 130. This bit must be interpreted to set the position invalid regardless of the indicated HIL or HPL.
(1) TSO C129. The requirements in DO-208 change 1 section 2.2.1.13.1 cover the time to alarm for different phases of flight. To properly comply with the overall 12 second integrity fault output for ADS-B, additional means of compliance for TSO-C129 requires GNSS manufacturers to provide information in the installation instructions describing the equipment integrity fault latency output with interface instructions and/or limitations for meeting the 12 second allocation set by 14 CFR 91.227.
(2) TSO C129a. The requirements in DO-208 change 1 section 2.2.1.13.1 cover the time to alarm for different phases of flight. To properly comply with the overall 12 second
Appendix 2 A2-8 integrity fault output for ADS-B, additional means of compliance for TSO-C129a requires GNSS manufacturers to provide information in the installation instructions describing the equipment integrity fault latency output with interface instructions and/or limitations for meeting the 12 second allocation set by this Advisory Circular.
(3) TSO C145/146 Rev a Class 1. Means of compliance for this TSO are defined in DO-229C sections 2.1.1.13, and 2.1.2.2.2.2.1 through 2.1.2.2.2.2.4.
(4) TSO C145/146 Rev a Class 2/3. Means of compliance for this TSO are defined in DO-229C sections 2.1.1.13, 2.1.2.2.2.2.1 through 2.1.2.2.2.2.4, and 2.1.4.2.2.2.1 through
2.1.4.2.2.2.3.
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO are defined in DO-229D sections 2.1.1.13, and 2.1.2.2.2.2.1 through 2.1.2.2.2.2.4.
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO are defined in DO-229D sections 2.1.1.13, 2.1.2.2.2.2.1 through 2.1.2.2.2.2.4, and 2.1.4.2.2.2.1 through
2.1.4.2.2.2.3.
(7) TSO C196/196a. Means of compliance for this TSO are defined in DO-316 sections 2.1.1.11, and 2.1.2.2.2.1 through 2.1.2.2.2.4.
g. Position integrity limits. The requirement was previously called Integrity Validity Limit. Single frequency RAIM-based HPL computations have been designed to support navigation applications and provide an appropriate error bound down to approximately 0.1 nautical mile (nm). While HPL values significantly smaller than 0.1 nm can be output from single frequency GNSS sources, if the HPL value was computed using RAIM, it may not actually achieve the reported level of protection as there are error contributions that are no longer negligible and should be taken into consideration. Such error sources specifically include correlation of ionospheric errors across satellites, tropospheric delay compensation errors, multipath, and receiver noise errors. This issue is not unique to un-augmented GPS position sources, as all revisions of TSO-C145 and TSO-C146 GNSS position sources also calculate integrity based on RAIM when Satellite-Based Augmentation System (SBAS) integrity is not used. Even when using SBAS augmentation, the integrity calculation is not required to account for these error sources except when in LNAV/VNAV or LPV/LP approach modes. ADS-B capable position sources must provide design information to the installer that identifies the following:
(1) Whether a TSO-C129 or TSO-C196 position source limits the HPL output to greater than 75 meters. If the position source does not limit its HPL output, the position source manufacturer should provide guidance to the ADS-B system installer to ensure the ADS-B equipment limits the NIC to ≤ 8. Although single frequency RAIM-based HPL values are only accurate down to approximately 0.1nm, for ADS-B purposes, the position source only need limit the HPL to greater than 75 meters, because an HPL greater than 75 meters ensures the ADS-B equipment will only set a NIC of ≤ 8.
Appendix 2 A2-9
(a) TSO C129. Means of compliance for this TSO requires GNSS manufacturers to present substantiation data whether HPL is limited or not, and provide proper installation instructions for the ADS-B integration.
(b) TSO C129a. Means of compliance for this TSO requires GNSS manufacturers to present substantiation data whether HPL is limited or not, and provide proper installation instructions for the ADS-B integration.
(c) TSO C196/196a. Means of compliance for this TSO requires GNSS manufacturers to present substantiation data whether HPL is limited or not, and provide proper installation instructions for the ADS-B integration.
(2) Whether a TSO-C145 or TSO-C146 position source limits the HPL in non-SBAS augmented modes to greater than 75 meters. If the position source does not limit the HPL output in non-augmented modes, the position source manufacturer should provide guidance to the ADS-B system installer to ensure the ADS-B equipment limits the NIC to ≤ 8 in non-augmented modes. The position source manufacturer should also provide instructions on how to determine the position source mode if appropriate.
(a) TSO C145/146 Rev a Class 1. Means of compliance for this TSO requires GNSS manufacturers to present substantiation data whether HPL is limited or not, and provide proper installation instructions for the ADS-B integration.
(b) TSO C145/146 Rev a Class 2/3. Means of compliance for this TSO requires GNSS manufacturers to present substantiation data whether HPL is limited or not, and provide proper installation instructions for the ADS-B integration. Installations intending to support NIC = 9 must use LNAV/VNAV or LPV/LP approach requirements (DO-229C section 2.1) at the time of HPL output, in accordance with TSO-C145/C146 rev a, but the enroute through LNAV K-Factor (6.18 vs.
6) must be applied (reference DO-229C Appendix J Section 2.1 and Appendix U Section 4). Either the GNSS source equipment sets the K-Factor for HPL, or the ADS-B equipment applies proper scaling. The GNSS manufacturer must present substantiation data on which K-Factor is used and provide proper installation instructions for the ADS-B integration.
(c) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO requires GNSS manufacturers to present substantiation data whether HPL is limited or not, and provide proper installation instructions for the ADS-B integration.
(d) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data whether HPL is limited or not, and provide proper installation instructions for the ADS-B integration. Installations intending to support NIC = 9 must use LNAV/VNAV or LPV/LP approach requirements (DO-229D Section 2.1) at the time of HPL output, in accordance with TSO-C145/C146 rev b/c, but the enroute through LNAV K-Factor (6.18 vs. 6) must be applied (refer to DO-229D Appendix J Section 3.1 and Appendix U Section 4). Either the GNSS source equipment sets the K-Factor for HPL, or the ADS-B equipment applies proper scaling. The GNSS manufacturer must present substantiation data on which K-Factor is used and provide proper installation instructions for the ADS-B integration.
Appendix 2 A2-10
h. Horizontal Position accuracy. GNSS position sources should provide a HFOM output which was demonstrated during the position source’s design approval or during an installation approval. GNSS certified under TSO-C145b/c, C146b/c, or all revisions of TSO-C196 are required to provide the HFOM output. TSO-C129, TSO-C145a, and TSO-C146a does not contain a horizontal position accuracy output requirement, however all equipment must provide a HFOM output in order to be considered an ADS-B compliant position source.
Note: The intent is to output position, velocity, and HFOM in a consistent manner for time of applicability (refer to DO-229D Section 2.1.2.6 and 2.1.2.6.2).
(1) TSO C129. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data showing the equipment computes and outputs HFOM. See the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-11 for an acceptable HFOM test.
(2) TSO C129a. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data showing the equipment computes and outputs HFOM. See the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-11 for an acceptable HFOM test.
(3) TSO C145/146 Rev a Class 1. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data based on the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-11 for an acceptable HFOM test.
(4) TSO C145/146 Rev a Class 2/3. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data based on the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-11 for an acceptable HFOM test.
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO are defined in DO-229D section 2.1.2.6 (also see section 1.7.1 and Appendix H of DO-229D).
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO are defined in DO-229D section 2.1.2.6 (also see section 1.7.1 and Appendix H of DO-229D).
(7) TSO C196/196a. Means of compliance for this TSO are defined in DO-316 section
2.1.2.6 (also see section 1.7.1 and Appendix H of DO-316).
i. 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 (i.e. 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 the geoid (HAG) instead of height above the ellipsoid (HAE). The position source manufacturer must provide data on whether the position source outputs HAE or HAG.
Appendix 2 A2-11
(1) TSO C129. Means of compliance for this TSO requires GNSS manufacturers to provide data to substantiate the output of HAE. The data produced to substantiate vertical position accuracy per the test described in the latest revision of AC 20-138 appendix 4, paragraph 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.
(2) TSO C129a. Means of compliance for this TSO requires GNSS manufacturers to provide data to substantiate the output of HAE. The data produced to substantiate vertical position accuracy per the test described in the latest revision of AC 20-138 appendix 4, paragraph 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.
(3) TSO C145/146 Rev a Class 1. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy per the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10 is sufficient.
(4) TSO C145/146 Rev a Class 2/3. For Class 2 equipment, the means of compliance for this requires GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy per the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10 is sufficient. Class 3 equipment complies with the ADS-B geometric altitude requirement per DO-229C section 2.1.5.8.
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy per the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10 is sufficient.
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy per the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10 is sufficient.
(7) TSO C196/196a. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data showing the equipment outputs HAE. The data produced to substantiate vertical position accuracy per the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10 is sufficient.
j. 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.
(1) TSO C129. Means of compliance is described in 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.
Appendix 2 A2-12
(2) TSO C129a. Means of compliance is described in 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 section (a)(5)(v) respectively.
(3) TSO C145/146 Rev a Class 1. Means of compliance for this TSO are defined in DO-229C section 2.1.2.6.1.
(4) TSO C145/146 Rev a Class 2. Means of compliance for this TSO are defined in DO-229C section 2.1.2.6.1 and 2.1.5.8.1.
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO are defined in DO-229D section 2.1.2.6.1.
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO are defined in DO-229D sections 2.1.2.6.1 and 2.1.5.8.1.
(7) TSO C196/196a. Means of compliance for this TSO are defined in DO-316 section
2.1.2.6.1.
k. 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 DO-229D Section 2.1.2.6 and 2.1.2.6.2).
(1) TSO C129. Means of compliance for this TSO requires GNSS manufacturers to perform the velocity test in the latest revision of AC 20-138, Appendix 4 and provide information substantiating the data is output.
(2) TSO C129a. Means of compliance for this TSO requires GNSS manufacturers to perform the velocity test in the latest revision of AC 20-138, Appendix 4 and provide information substantiating the data is output.
(3) TSO C145/146 Rev a Class 1. Means of compliance for this TSO are defined in DO-229C section 2.1.2.6 along with the test defined in the latest revision of AC 20-138 Appendix
4.
(4) TSO C145/146 Rev a Class 2/3. Means of compliance for this TSO are defined requirements are defined in DO-229C section 2.1.2.6 along with the test defined in the latest revision of AC 20-138 Appendix 4.
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO are defined in DO-229D section 2.1.2.6. The TSO requirement is only to output velocity, but there is no
Appendix 2 A2-13 accuracy requirement. Satisfying this ADS-B requirement means the GNSS manufacturer must also comply with paragraph 4.n of this appendix (Horizontal Velocity Accuracy) and the associated velocity accuracy tests.
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO are defined in 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 paragraph 4.n of this appendix (Horizontal Velocity Accuracy) and the associated velocity accuracy tests.
(7) TSO C196/196a. Means of compliance for this TSO are defined in 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 paragraph 4.n of this appendix (Horizontal Velocity Accuracy) and the associated velocity accuracy tests.
Note: The velocity test found in the latest revision AC 20-138 is also defined in section 2.3.6.4 of DO-316.
l. Groundspeed. It is recommended that the position source output groundspeed. GNSS manufacturers choosing to output groundspeed may show compliance as described below for the appropriate TSO.
(1) TSO C129. Means of compliance for this TSO requires GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (i.e., in a groundspeed format versus north/east velocity format) and the protocols used.
(2) TSO C129a. Means of compliance for this TSO requires GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (i.e., in a groundspeed format versus north/east velocity format) and the protocols used.
(3) TSO C145/146 Rev a Class 1. The Gamma equipment requirements outlined in 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 DO-229D, Appendix H. Additional means of compliance for TSO-C145/146 Rev a Class 1 requires GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (i.e., in a groundspeed format versus north/east velocity format) and the protocols used.
(4) TSO C145/146 Rev a Class 2/3. The Gamma equipment requirements outlined in 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 DO-229C, Appendix H. Additional means of compliance for TSO-C145/146 Rev a Class 2/3 requires GNSS manufacturers to provide information in the installation instructions describing
Appendix 2 A2-14 how the velocity is output (i.e., in a groundspeed format versus north/east velocity format) and the protocols used.
(5) TSO C145/146 Rev b/c Class 1. Gamma-1 equipment requirements outlined in 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 DO-229D, Appendix H. Additional means of compliance for TSO-C145/146 Rev b/c Class 1 requires GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (i.e., in a groundspeed format versus north/east velocity format) and the protocols used.
(6) TSO C145/146 Rev b/c Class 2/3. Gamma-2 and Gamma-3 equipment requirements outlined in 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 DO-229D, Appendix H. Additional means of compliance for TSO-C145/146 Rev b/c Class 2/3 requires GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (i.e., in a groundspeed format versus north/east velocity format) and the protocols used.
(7) TSO C196/196a. Means of compliance for this TSO requires GNSS manufacturers to provide information in the installation instructions describing how the velocity is output (i.e., in a groundspeed 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 DO-316 Appendix H.
m. Time of Applicability. The GNSS equipment must output a time of applicability.
Note: The intent is to output position, velocity, and HFOM in a consistent manner for time of applicability (refer to DO-229D Section 2.1.2.6 and 2.1.2.6.2).
(1) TSO C129. Means of compliance for this TSO requires 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 time of measurement to time of applicability requirement and account for the impulse response of the position solution.
(2) TSO C129a. Means of compliance for this TSO requires 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 of applicability requirement and account for the impulse response of the position solution.
(3) TSO C145/146 Rev a Class 1. Means of compliance for this TSO are defined in DO-229C sections 2.1.2.6 and 2.1.2.6.2.
(4) TSO C145/146 Rev a Class 2/3. Means of compliance for this TSO are defined in DO-229C sections 2.1.2.6, 2.1.2.6.2, and 2.1.5.8.2.
Appendix 2 A2-15
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO are defined in DO-229D sections 2.1.2.6 and 2.1.2.6.2.
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO are defined in DO-229D sections 2.1.2.6, 2.1.2.6.2, and 2.1.5.8.2.
(7) TSO C196/196a. Means of compliance for this TSO are defined in DO-316 sections 2.1.2.6 and 2.1.2.6.2.
n. 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.
(1) NACV = 1. For installations intending to support NACV = 1, the GNSS manufacturer must perform the velocity tests in AC 20-138C, appendix 4 paragraph 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.
(2) NACV. = 2. For installations intending to support NACV = 2, the GNSS manufacturer must perform the velocity tests in AC 20-138C, Appendix 4 paragraphs 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 (see AC 20-138() appendix 4, paragraphs 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.
(3) NACV. = 3 or 4. No standard for performance has been developed to support NACV = 3 or 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.
(4) TSO C129. Means of compliance for this TSO requires 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. See AC 20-138() appendix 4, paragraph A4-2.d(3) for additional guidance relative to using the noise environment in DO-235B for the velocity tests.
(5) TSO C129a. Means of compliance for this TSO requires 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. See AC 20-138() appendix 4, paragraph A4-2.d(3) for additional guidance relative to using the noise environment in DO-235B for the velocity tests.
Appendix 2 A2-16
(6) TSO C145/146 Rev a Class 1. Means of compliance for this TSO requires 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.
(7) TSO C145/146 Rev a Class 2/3. Means of compliance for this TSO requires 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.
(8) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO requires 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.
(9) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO requires 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.
(10) TSO-C196/196a. Means of compliance for this TSO requires 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.
o. Vertical position accuracy. The GNSS should output vertical position accuracy. The vertical accuracy should specify a 95% 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.
(1) TSO C129. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10.
(2) TSO C129a. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10.
(3) TSO C145/146 Rev a Class 1. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10.
(4) TSO C145/146 Rev a Class 2. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10.
Appendix 2 A2-17
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10.
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in the latest revision of AC 20-138 appendix 4, paragraph A4-10.
(7) TSO C196/196a. Means of compliance for this TSO requires GNSS manufacturers to provide substantiation data along with the VFOM output based on the test described in the latest revision of AC 20-138 appendix 4 paragraph A4-10.
p. 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.
(1) TSO C129. Means of compliance for this TSO requires 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 (See Integrity Limit, paragraph 4.g, of this appendix).
(2) TSO C129a. Means of compliance for this TSO requires 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 (See Integrity Limit, paragraph 4.g, of this appendix).
(3) TSO C145/146 Rev a Class 1. Means of compliance for this TSO requires 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 (See Integrity Limit, paragraph 4.g, of this appendix).
(4) TSO C145/146 Rev a Class 2. Means of compliance for this TSO requires 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 (See Integrity Limit, paragraph 4.g, of this appendix).
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO requires 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 (See Integrity Limit, paragraph 4.g, of this appendix).
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO requires GNSS manufacturers to provide installation instructions describing the modes available (if affecting
Appendix 2 A2-18 interpretation of integrity output) and how the position source outputs the mode indication (See Integrity Limit, paragraph 4.g, of this appendix).
(7) TSO C196/196a. Means of compliance for this TSO requires 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 (See Integrity Limit, paragraph 4.g, of this appendix).
q. 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. Reference 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% 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 (i.e., 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.
(1) TSO C129. This is not applicable to this TSO as no HPL scaling is applied.
(2) TSO C129a. This is not applicable to this TSO as no HPL scaling is applied.
(3) TSO C145/146 Rev a Class 1. Means of compliance for this TSO are defined in DO-229C sections 2.1.1.13.1 and 2.1.3.2.2.
(4) TSO C145/146 Rev a Class 2/3. Means of compliance for this TSO are defined in DO-229C sections 2.1.1.13.1, 2.1.3.2.2, 2.1.4.2.2, and 2.1.5.2.2.
(5) TSO C145/146 Rev b/c Class 1. Means of compliance for this TSO are defined in DO-229D sections 2.1.1.13.1 and 2.1.3.2.2.
(6) TSO C145/146 Rev b/c Class 2/3. Means of compliance for this TSO are defined in DO-229D sections 2.1.1.13.1, 2.1.3.2.2, 2.1.4.2.2, and 2.1.5.2.2.
(7) TSO C196/196a. This is not applicable to this TSO as no HPL scaling is applied.
r. 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 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, then the position source manufacturer must provide information on velocity limitations for GNSS track angle.