Deviates from ETSO-C145eA1 §3.1, DO-229E and ETSO-C145eA1 Appendix 4, to use IS-GPS-200H instead of IS-GPS-200D for the demodulation of GPS signals and signal processing, provided that the following features of IS-GPS-200H and only these are used:
- Signal tracking and data demodulation limited to GPS L1C/A signals from GPS PRN 1 to 32 and to Legacy NAV (LNAV) of Block II, Block IIA, Block IIR, Block IIR-M, Block IIF and GPS III satellites.
- Data demodulation restricted to Legacy NAV (LNAV) data defined in IS-GPS-200H appendix II and to the use of the following bit fields and associated requirements:
- Default navigation pattern
- Null navigation pattern
- bit 25 to 30 of all GPS words: parity
- bit 1 to 8 of all GPS subframes: preamble
- bit 23 of all GPS sub frames: Integrity Status Flag (optional provided Note 1 is fulfilled)
- bit 31 to 48 of all GPS subframes: time of week, alert flag
- bit 50 to 52 of all GPS subframe: subframe ID
- bit 61 to 70 of GPS Subframe 1: week number
- bit 73 to 84 of GPS Subframe 1: URA, Health, IODC MSB
- bit 197 to 204 of GPS Subframe 1: TGD
- bit 211 to 234 of GPS Subframe 1: IODC LSB, TOC
- bit 241 to 264 of GPS Subframe 1: Ephem Af2, Af1
- bit 271 to 292 of GPS Subframe 1: Ephem Af0
- bit 61 to 84 of GPS Subframe 2: IODE, Ephem CRS
- bit 91 to 114 of GPS Subframe 2: Ephem DeltaN, Ephem M0 MSB
- bit 121 to 144 of GPS Subframe 2: Ephem M0 LSB
- bit 151 to 174 of GPS Subframe 2: Ephem CUC, Ephem e MSB
- bit 181 to 204 of GPS Subframe 2: Ephem e LSB
- bit 211 to 234 of GPS Subframe 2: Ephem CUS, Ephem SqrtA MSB
- bit 241 to 264 of GPS Subframe 2: Ephem SqrtA LSB
- bit 271 to 287 of GPS Subframe 2: Ephem TOE, Ephem Fit interval flag
- bit 61 to 84 of GPS Subframe 3: Ephem CIC, Ephem Omega0 MSB
- bit 91 to 114 of GPS Subframe 3: Ephem Omega0 LSB
- bit 121 to 144 of GPS Subframe 3: Ephem CIS, Ephem I0 MSB
- bit 151 to 174 of GPS subframe 3: Ephem I0 LSB
- bit 181 to 204 of GPS subframe 3: Ephem CRC, Ephem Omega MSB
- bit 211 to 234 of GPS subframe 3: Ephem Omega LSB
- bit 241 to 264 of GPS subframe 3: Ephem Omega dot
- bit 271 to 292 of GPS subframe 3: Ephem IODE, Ephem Idot
- bit 60 to 61 of GPS sub frame 4 and 5: Data ID Number
- bit 63 to 68 of GPS subframe 4 and 5: SV ID
- bit 69 to 84 of GPS subframe 4 and 5 with SV ID = 1 to 32: Alm e
- bit 91 to 114 of GPS subframe 4 and 5 with SV ID = 1 to 32: Alm TOA, Alm DeltaI
- bit 121 to 136 of GPS subframe 4 and 5 with SV ID = 1 to 32: Alm OmegaDot
- bit 151 to 174 of GPS subframe 4 and 5 with SV ID = 1 to 32: Alm SqrtA
- bit 181 to 204 of GPS subframe 4 and 5 with SV ID = 1 to 32: Alm Omega0
- bit 211 to 234 of GPS subframe 4 and 5 with SV ID = 1 to 32: Alm Omega
- bit 241 to 264 of GPS subframe 4 and 5 with SV ID = 1 to 32: Alm M0
- bit 69 to 84 of GPS subframe 4 with SV ID = 56: Iono Alpha0, Iono Alpha1
- bit 91 to 114 of GPS subframe 4 with SV ID = 56: Iono Alpha2, Iono Alpha3, Iono Beta0
- bit 121 to 144 of GPS subframe 4 with SV ID = 56: Iono Beta1, Iono Beta2, Iono Beta3
- bit 151 to 174 of GPS subframe 4 with SV ID = 56: UTC A1
- bit 181 to 204 of GPS subframe 4 with SV ID = 56: UTC A0 MSB
- bit 211 to 234 of GPS subframe 4 with SV ID = 56: UTC A0 LSB, UTC TOT, UTC WNT
- bit 241 to 264 of GPS subframe 4 with SV ID = 56: UTC DTLS, UTC WNLSF, UTC DN
- bit 271 to 278 of GPS subframe 4 with SV ID = 56: UTC DTLSF
Note 1: As the new definition in IS-GPS-200H is a superset of the definition in IS-GPS-200D, it is accepted to not decode this Integrity Status Flag bit if only the IS-GPS-200D definition is used i.e. the probability of the URE exceeding 4.42 times URA for more than 5.2 seconds, without an accompanying alert, is less than 1E-5 per hour. In this context, an "alert" is defined as any indication or characteristic of the conveying signal.
Details
Consultation / Publication Type
Consultation Status
Consultation closed
Superseded Status
Not superseded
Deadline for Comments
13/07/2021
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