IS-GPS-800A - US Coast Guard Navigation Center
IS-GPS-800A - US Coast Guard Navigation Center IS-GPS-800A - US Coast Guard Navigation Center
transmitted by the SVs will degrade over time.3.5.4.3.5.1 Reduced Almanac PacketThe following shall apply when interpreting the data provided in each packet of reduced almanac (see Figure 3.5-9).3.5.4.3.5.1.1 Reduced AlmanacThe reduced almanac data is provided in bits 9 through 30 of each packet. The data from a packet along with thereference values (see Table 3.5-6) provide ephemeris with further reduced precision. The user algorithm isessentially the same as the user algorithm employed for computing the ephemeris from the parameters in subframe 2(see Section 3.5.3.6.1 and Table 3.5-2). Other parameters appearing in the equations of Table 3.5-2, but notprovided by the reduced almanac with the reference values, are set to zero for SV position determination.33 BITS1 9 17 24 31 32 33PRN a A 0 08 BITS8 BITS7 BITS7 BITSL1 HEALTHL2 HEALTH* See Figures 3.5-4 for complete bit allocation in the message.L5 HEALTHFigure 3.5-9. Reduced Almanac Packet Content58 IS-GPS-800A8 June 2010
Table 3.5-6. Reduced Almanac Parameters *****Parameter***** No. of Bits Scale Factor (LSB) Effective Range ** Units A *** 0 0 ****8 *7 *7 *2 +9**2 -6**2 -6 **Meterssemi-circlessemi-circles* Parameters so indicated shall be in two’s complement notation;** Effective range is the maximum range attainable with indicated bit allocation and scale factor;*** Relative to A ref = 26,559,710 meters;**** 0 = Argument of Latitude at Reference Time = M 0 + ;***** Relative to following reference values:e = 0 i = +0.0056 semi-circles (i = 55 degrees)Ω =-2.6 x 10 -9 semi-circles/second3.5.4.3.6 Midi Almanac Parameter ContentSubframe 3, page 4 shall contain Midi almanac data for a SV whose PRN number is specified in the message. Thebit lengths, scale factors, ranges, and units of the almanac parameters are given in Table 3.5-7. The user algorithm isessentially the same as the user algorithm employed for computing the ephemeris as specified in Table 20-IV of IS-GPS-200. Other parameters appearing in the equations of Table 20-IV of IS-GPS-200, but not provided by the Midialmanac with the reference values, are set to zero for SV position determination. See paragraph 20.3.3.5.2.3 of IS-GPS-200 for almanac time parameters.59 IS-GPS-800A8 June 2010
- Page 15 and 16: 3.2.2 PRN Code CharacteristicsThe c
- Page 17 and 18: The overlay codes are derived from
- Page 19 and 20: 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 42 and 43: DIRECTION OF DATA FLOW FROM SV100 B
- Page 44 and 45: 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 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 76 and 77: LSF - Leap Seconds FutureL1C - Comm
- 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 82 and 83: Table 6.2-2 LDPC Submatrix A for Su
- Page 84 and 85: Table 6.2-2 LDPC Submatrix A for Su
- Page 86 and 87: Table 6.2-2 LDPC Submatrix A for Su
- Page 88 and 89: 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 110 and 111: Table 6.3-1 Additional L1C Ranging
- Page 112 and 113: Table 6.3-1 Additional L1C Ranging
- Page 114 and 115: PRNSignalNo.Table 6.3-2. Additional
Table 3.5-6. Reduced Almanac Parameters *****Parameter***** No. of Bits Scale Factor (LSB) Effective Range ** Units A *** 0 0 ****8 *7 *7 *2 +9**2 -6**2 -6 **Meterssemi-circlessemi-circles* Parameters so indicated shall be in two’s complement notation;** Effective range is the maximum range attainable with indicated bit allocation and scale factor;*** Relative to A ref = 26,559,710 meters;**** 0 = Argument of Latitude at Reference Time = M 0 + ;***** Relative to following reference values:e = 0 i = +0.0056 semi-circles (i = 55 degrees)Ω =-2.6 x 10 -9 semi-circles/second3.5.4.3.6 Midi Almanac Parameter ContentSubframe 3, page 4 shall contain Midi almanac data for a SV whose PRN number is specified in the message. Thebit lengths, scale factors, ranges, and units of the almanac parameters are given in Table 3.5-7. The user algorithm isessentially the same as the user algorithm employed for computing the ephemeris as specified in Table 20-IV of <strong>IS</strong>-<strong>GPS</strong>-200. Other parameters appearing in the equations of Table 20-IV of <strong>IS</strong>-<strong>GPS</strong>-200, but not provided by the Midialmanac with the reference values, are set to zero for SV position determination. See paragraph 20.3.3.5.2.3 of <strong>IS</strong>-<strong>GPS</strong>-200 for almanac time parameters.59 <strong>IS</strong>-<strong>GPS</strong>-<strong>800A</strong>8 June 2010
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