Интерфейсный документ GPS, страница 3

GPS Time .........................................................................................................19030.3.4.3 Speed of Light .......................................................................................................................19030.3.5 Data Frame Parity............................................................................................................................19130.3.5.1 Parity Algorithm....................................................................................................................191IS-GPS-200D7 Dec 2004xiLIST OF FIGURESFigure 3-1.Generation of P-, C/A-Codes and Modulating Signals ...................................................................19Figure 3-2.X1A Shift Register Generator Configuration..................................................................................21Figure 3-3.X1B Shift Register Generator Configuration..................................................................................22Figure 3-4.X2A Shift Register Generator Configuration..................................................................................23Figure 3-5.X2B Shift Register Generator Configuration..................................................................................24Figure 3-6.P-Code Generation..........................................................................................................................26Figure 3-7.P-Code Signal Component Timing .................................................................................................27Figure 3-8.G1 Shift Register Generator Configuration ....................................................................................31Figure 3-9.G2 Shift Register Generator Configuration ....................................................................................32Figure 3-10.Example C/A-Code Generation ......................................................................................................33Figure 3-11.C/A-Code Timing Relationships.....................................................................................................34Figure 3-12.L2 CM-/L2 CL-Code Timing Relationships ...................................................................................36Figure 3-13.L2 CM/L2 CL Shift Register Generator Configuration ..................................................................37Figure 3-14.Convolutional Encoder ...................................................................................................................39Figure 3-15.Convolutional Transmit/Decoding Timing Relationships...............................................................39Figure 3-16.Time Line Relationship of HOW Message .....................................................................................42Figure 6-1.User Received Minimum Signal Level Variations (Example, Block II/IIA/IIR)............................54Figure 10-1.Letters of Exception.

.......................................................................................................................59Figure 20-1.Data Format ....................................................................................................................................69Figure 20-2.TLM and HOW Formats.................................................................................................................82Figure 20-3.Sample Application of Correction Parameters................................................................................92Figure 20-4.Ionospheric Model ........................................................................................................................123Figure 20-5.Example Flow Chart for User Implementation of Parity Algorithm.............................................135Figure 30-1.Message Type 10 - Ephemeris 1 ...................................................................................................141Figure 30-2.Message Type 11 - Ephemeris 2 ...................................................................................................142Figure 30-3.Message Type 30 - Clock, IONO & Group Delay ........................................................................143Figure 30-4.Message Type 31 - Clock & Reduced Almanac ...........................................................................144Figure 30-5.Message Type 32 - Clock & EOP .................................................................................................145Figure 30-6.Message Type 33 - Clock & UTC.................................................................................................146Figure 30-7.Message Type 34 - Clock & Differential Correction ....................................................................147Figure 30-8.Message Type 35 - Clock & GGTO .............................................................................................148Figure 30-9.Message Type 36 - Clock & Text .................................................................................................149Figure 30-10.Message Type 37 - Clock & Midi Almanac .................................................................................150IS-GPS-200D7 Dec 2004xiiFigure 30-11.Message Type 12 - Reduced Almanac..........................................................................................151Figure 30-12.Message Type 13 – Clock Differential Correction .......................................................................152Figure 30-13.Message Type 14 – Ephemeris Differential Correction ................................................................153Figure 30-14.Message Type 15 - Text................................................................................................................154Figure 30-15.Reduced Almanac Packet Content ................................................................................................174Figure 30-16.Differential Correction Data Packet..............................................................................................182IS-GPS-200D7 Dec 2004xiiiLIST OF TABLESTable 3-I.Code Phase Assignments ..................................................................................................................7Table 3-II.Code Phase Assignments (IIR-M, IIF, and subsequent blocks only)................................................9Table 3-III.Signal Configuration .......................................................................................................................13Table 3-IV.Composite L1 Transmitted Signal Phase ........................................................................................16Table 3-V.Received Minimum RF Signal Strength .........................................................................................16Table 3-VI.P-Code Reset Timing ......................................................................................................................28Table 3-VII.Final Code Vector States.................................................................................................................29Table 20-I.Subframe 1 Parameters ...................................................................................................................87Table 20-II.Ephemeris Data Definitions ............................................................................................................94Table 20-III.Ephemeris Parameters.....................................................................................................................96Table 20-IV.Elements of Coordinate Systems ....................................................................................................97Table 20-V.Data IDs and SV IDs in Subframes 4 and 5..................................................................................105Table 20-VI.Almanac Parameters .....................................................................................................................107Table 20-VII.NAV Data Health Indications .......................................................................................................109Table 20-VIII.Codes for Health of SV Signal Components.................................................................................110Table 20-IX.UTC Parameters............................................................................................................................113Table 20-X.Ionospheric Parameters .................................................................................................................114Table 20-XI.IODC Values and Data Set Lengths (Block II/IIA) .....................................................................128Table 20-XII.IODC Values and Data Set Lengths (Block IIR/IIR-M/IIF) ........................................................129Table 20-XIII.Reference Times ...........................................................................................................................132Table 20-XIV.Parity Encoding Equations............................................................................................................134Table 30-I.Message Types 10 and 11 Parameters...........................................................................................159Table 30-II.Elements of Coordinate System ....................................................................................................161Table 30-III.Clock Correction and Accuracy Parameters .................................................................................164Table 30-IV.Group Delay Differential Parameters............................................................................................168Table 30-V.Midi Almanac Parameters.............................................................................................................173Table 30-VI.Reduced Almanac Parameters.......................................................................................................174Table 30-VII.Earth Orientation Parameters .........................................................................................................176Table 30-VIII.Application of EOP Parameters .....................................................................................................177Table 30-IX.UTC Parameters............................................................................................................................180Table 30-X.Differential Correction Parameters.................................................................................................183Table 30-XI.GPS/GNSS Time Offset Parameters .............................................................................................188Table 30-XII.Message Broadcast Intervals.........................................................................................................189IS-GPS-200D7 Dec 2004xiv1.