IS-GPS-800A - US Coast Guard Navigation Center

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LSF - Leap Seconds FutureL1C - Common L1 SignalMCS - Master Control StationMHz - MegahertzMSB - Most Significant BitNAV - Legacy Navigation Message, D(t)NSCD - non-standard L1C DNSCP - non-standard L1C PPIRN - Proposed Interface Revision NoticePRN - Pseudo-Random NoiseRF - Radio FrequencyRHCP - Right-Hand Circularly PolarizedRMS - Root Mean SquareSBAS - Satellite Based Augmentation Systemsps - symbols per secondSS - Space SegmentSSV - Space Service VolumeSV - Space VehicleTBD - To Be DeterminedTBR - To Be ResolvedTBS - To Be SuppliedTMBOC - Time-Multiplexed BOCTOI - Time of IntervalTOW - Time of WeekUDRA - User Differential Range AccuracyUE - User EquipmentURA - User Range AccuracyUS - User SegmentUSNO - U.S. Naval ObservatoryUTC - Coordinated Universal TimeWGS 84 - World Geodetic System 19846.2 Definitions6.2.1 User Range AccuracyUser Range Accuracy (URA) is a statistical indicator of the GPS ranging accuracy obtainable with a specific signaland SV. Whether the integrity status flag is ‘off’ or ‘on’, 4.42 times URA bounds instantaneous URE under all68 IS-GPS-800A8 June 2010
conditions with 1 -1e-5 per hour probability. When the integrity status flag is ‘on’, 5.73 times URA boundsinstantaneous URE under all conditions with 1-1e-8 per hour probability.Note #1: URA applies over the curve fit interval that is applicable to the NAV data from which the URA is read, forthe worst-case location within the intersection of the satellite signal and the terrestrial service volume.Note #2: The URA for a particular signal may be represented by a single parameter in the NAV data or by more thanone parameter representing components of the total URA. Specific URA parameters and formulae for calculating thetotal URA for a signal are defined in the applicable Space Segment to Navigation User Segment ICD’s.6.2.1.1 Integrity Assured URAWhen the integrity assurance monitoring is available, as indicated by the “integrity status flag” being set to “1”, theURA value is chosen such that the probability of the “actual” URE exceeding a threshold is met (see section3.5.3.10 for probability values). The URA value is conveyed to the user in the form of a URA index value. TheURA index represents a range of values; for integrity assurance applications, it is prudent to use the RSS of thelargest URA index values in the URA index range.6.2.1.2 User Differential Range AccuracyUser Differential Range Accuracy (UDRA) is a statistical indicator of the GPS ranging accuracy obtainable with aspecific signal and SV after the application of the associated differential corrections (DC parameters).6.2.2 GPS Week NumberThe GPS week numbering system is established with week number zero (0) being defined as that week whichstarted with the X1 epoch occurring at midnight UTC(USNO) on the night of January 5, 1980/ morning of January6, 1980. The GPS week number continuously increments by one (1) at each end/start of week epoch without everresetting to zero. Users must recognize that the week number information contained in the navigation message maynot necessarily reflect the current full GPS week number (see paragraph 3.5.3.1).6.2.3 Legendre SequenceThe Legendre sequence L(t) of length 10223, defined in Section 3.2.2.1.1, is given in Table 6.2-1.6.2.4 LDPC SubmatricesThis section defines the coordinates of elements with value “1” in each of the submatrices specified in Section 3.2.3.4.Tables 6.2-2, 6.2-3, 6.2-4, 6.2-5, 6.2-6, and 6.2-7 define the coordinates of elements with value “1” in each of thesubmatrices A, B, C, D, E, and T, respectively, for Subframe 2. Tables 6.2-8, 6.2-9, 6.2-10, 6.2-11, 6.2-12, and 6.2-13define the coordinates of elements with value “1” in each of the submatrices A, B, C, D, E, and T, respectively, forSubframe 3.Due to large amount of information provided in some of the submatrix tables, supplemental information is provided inTables 6.2-14, 6.2-15, 6.2-16, and 6.2-17. The supplemental information tables provide the number of 1’s in each rowand column of submatrices A and T for subframes 2 and 3.69 IS-GPS-800A8 June 2010
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IS-GPS-800A8 June 2010GLOBAL POSITI
Page 3 and 4:
REVISION RECORDLTR DESCRIPTION DATE
Page 5 and 6:
3.2.3.3 Cyclic Redundancy Check ...
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LIST OF FIGURESFigure 3.2-1. Genera
Page 9 and 10:
1. INTRODUCTION1.1 ScopeThis Interf
Page 11 and 12:
3. SIGNAL REQUIREMENTSThe requireme
Page 13 and 14:
Carriers of the two L1C components
Page 15 and 16:
3.2.2 PRN Code CharacteristicsThe c
Page 17 and 18:
The overlay codes are derived from
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3.2-2 L1C Ranging Codes Parameter A
Page 21 and 22:
GPS PRNSignal No.3.2-3 L1C O Overla
Page 23 and 24:
FIXED LENGTH-10223 LEGENDRE SEQUENC
Page 25 and 26: 3.2.2.2 Non-Standard CodesThe non-s
Page 27 and 28: corresponding to MSB = 0. (A SV tra
Page 29 and 30: This code has the following charact
Page 31 and 32: 3.2.3.5 InterleavingThe 1748 encode
Page 33 and 34: 3.3 Signal ModulationThe signals mo
Page 35 and 36: Bit valueL1C DbitstreamSubcarrier s
Page 37 and 38: 3.5 Message DefinitionAs shown in F
Page 40 and 41: DIRECTION OF DATA FLOW FROM SV100 B
Page 46 and 47: 3.5.3 Subframe 2Subframe 2 provides
Page 48 and 49: Table 3.5-1. Subframe 2 Parameters
Page 50 and 51: 3.5.3.1 Transmission Week NumberBit
Page 52 and 53: 3.5.3.6 Ephemeris Parameter Charact
Page 54 and 55: Table 3.5-2. Elements of Coordinate
Page 56 and 57: The user shall use the broadcast UR
Page 58 and 59: where, ISC L1CD is provided to the
Page 60 and 61: 3.5.3.10.1 Integrity Status Flag (I
Page 62 and 63: The ionospheric data shall be updat
Page 64 and 65: 3.5.4.2.3 User Algorithm for Applic
Page 66 and 67: transmitted by the SVs will degrade
Page 68 and 69: Table 3.5-7.Midi Almanac Parameters
Page 70 and 71: MSBCDC = Clock Differential Correct
Page 72 and 73: 3.5.4.5 Subframe 3, Page 6 - TextSu
Page 74 and 75: 5. RESERVED66 IS-GPS-800A8 June 201
Page 78 and 79: Table 6.2-1.Legendre Sequence (Octa
Page 80 and 81: Table 6.2-2 LDPC Submatrix A for Su
Page 90 and 91: Table 6.2-3. LDPC Submatrix B for S
Page 92 and 93: Table 6.2-7. LDPC Submatrix T for s
Page 94 and 95: Table 6.2-7. LDPC Submatrix T for s
Page 96 and 97: Table 6.2-8. LDPC Submatrix A for s
Page 98 and 99: Table 6.2-8. LDPC Submatrix A for s
Page 100 and 101: Table 6.2-9. LDPC Submatrix B for S
Page 102 and 103: Table 6.2-13. LDPC Submatrix T for
Page 104 and 105: Table 6.2-16. Number of 1’s in LD
Page 106 and 107: 6.3 Supporting Material6.3.1 Additi
Page 108 and 109: Table 6.3-1 Additional L1C Ranging
Page 114 and 115: PRNSignalNo.Table 6.3-2. Additional
Page 116 and 117: PRNSignalNo.Table 6.3-2 Additional
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IS-GPS-800A - US Coast Guard Navigation Center

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