GLOBAL NAVIGATION SATTELITE SYSTEM GLONASS

1 GLOBAL NAVIGATION SATTELITE SYSTEM GLONASS INTERFACE CONTROL DOCUMENT Navigational radiosignal In bands L1, L2 (Edition ) MOSCOW 2008 Edition 2008 ICD L1, L2 GLONASS Russian Institute of Space Device Engineering Edition 2008 ICD L1, L2 GLONASS Russian Institute of Space Device Engineering Edition 2008 ICD L1, L2 GLONASS Russian Institute of Space Device Engineering FIGURES .. 5 TABLES .. 5 1. 8 GLONASS 8 GLONASS 8 NAVIGATION DETERMINATION 9 2. GENERAL .. 10 ICD 10 ICD APPROVAL AND 10 3. REQUIREMENTS .. 12 INTERFACE 12 NAVIGATION SIGNAL 12 Ranging 13 Digital data of NAVIGATION message.

2 13 INTERFACE 13 NAVIGATION RF signal characteristics .. 13 Modulation .. 17 GLONASS time .. 22 Coordinate 23 4. NAVIGATION 25 NAVIGATION MESSAGE 25 NAVIGATION MESSAGE 25 NAVIGATION MESSAGE 25 Superframe structure .. 26 Frame structure .. 27 String 29 IMMEDIATE INFORMATION AND EPHEMERIS 30 NON-IMMEDIATE INFORMATION AND 36 RESERVED 41 DATA VERIFICATION 42 5 GLONASS SPACE SEGMENT .. 43 CONSTELLATION 43 ORBITAL 44 INTEGRITY 45 RECEIVED POWER LEVEL IN L1 AND L2 46 APPENDIX 2 .. 48 Edition 2008 ICD L1, L2 GLONASS Russian Institute of Space Device Engineering RECOMMENDATIONS FOR USERS ON OPERATION OF ECEIVER DURING UTC LEAP SECOND CORRECTION.

3 48 APPENDIX 3 .. 50 FIGURES page Fig. Interface NKA/NAP 14 Fig. Structure of the shift register shaping a ranging code 20 Fig. Simplified block diagramme of PSPD ranging creation code and sync signals for a navigational radiosignal 21 Fig. Simplified block diagramme of data creation series 21 Fig. T Temporal ratio between sync signals of a modulating navigational signal and PSPD ranging code 22 Fig. series creation in NKA processor 22 Fig. Superframe structure 29 Fig. Frame structure 31 Fig.

4 String structure 32 Fig. of Item 1 Relation between the radiosignal amplifying underpower and elevation angle 52 TABLES page Table GLONASS carrier frequencies in L1 and L2 sub-bands 15 Table Geodetic constants and parameters of common terrestrial ellipsoid 25 Table Arrangement of GLONASS almanac within superframe 30 Table Accuracy of transmitted of coordinates and velocity for GLONASS satellite 33 Table Word P1 34 Table Word FT 36 Table Characteristics of words of

5 Immediate information (ephemeris parameters) 37 Table Arrangement of immediate information within frame 39 Table Word KP 42 Table Relationship between "age" of almanac and accuracy of positioning 42 Table Characteristics of words of non-immediate information (almanac) 43 Edition 2008 ICD L1, L2 GLONASS Russian Institute of Space Device Engineering Table Negative numbers of GLONASS carriers within NAVIGATION message 45 Table Arrangement of non-immediate information within frame 45 Table Arrangement of reserved bits within super frame 46 Table Algorithm for verification of data within string 48 Table Health flags and operability of the satellite 51 Edition 2008 ICD L1.

6 L2 GLONASS Russian Institute of Space Device Engineering ABBREVIATIONS BIH Bureau International de l'Heure CCIR Consultative Committee for International Radio CS Central Synchronizer FDMA Frequency division multiple access GMT Greenwich Mean Time ICD Interface Control Document KNITs Coordination Scientific Information Center KX Hamming Code LSB Least Significan Bit MT Moscow Time MSB Most Significan Bit msd mean-solar day NPO PM Scientific and Production Association of Applied Mechanics PR Pseudo random RF Radio frequency RMS ( ) Root mean square ROM Read only memory RNII KP Research Institute of Space Device Engineering UTC Coordinated Universal Time Edition 2008 ICD L1, L2 GLONASS Russian Institute of Space Device Engineering 1.

7 INTRODUCTION GLONASS purpose The purpose of the GLOBAL NAVIGATION Satellite SYSTEM GLONASS is to provide unlimited number of air, marine, and any other type of users with all-weather three-dimensional positioning, velocity measuring and timing anywhere in the world or near-earth space. GLONASS components GLONASS includes three components: Constellation of satellites (space segment); Ground-based control facilities (control segment); User equipment (user segment). Completely deployed GLONASS constellation is composed of 24 satellites in three orbital planes whose ascending nodes are 120 apart. 8 satellites are equally spaced in each plane with argument of latitude displacement 45. The orbital planes have 15 -argument of latitude displacement relative to each other.

8 The satellites operate in circular 19100-km orbits at an inclination , and each satellite completes the orbit in approximately 11 hours 15 minutes. The spacing of the satellites allows providing continuous and GLOBAL coverage of the terrestrial surface and the near-earth space. The control segment includes the SYSTEM Control Center and the network of the Command and Tracking Stations that are located throughout the territory of Russia. The control segment provides monitoring of GLONASS constellation status, correction to the orbital parameters and NAVIGATION data uploading. User equipment consists of receives and processors receiving and processing the GLONASS NAVIGATION signals, and allows user to calculate the coordinates, velocity and time.

9 Edition 2008 ICD L1, L2 GLONASS Russian Institute of Space Device Engineering NAVIGATION determination concept User equipment performs passive measurements of pseudoranges and pseudorange rate of four (three) GLONASS satellites as well as receives and processes NAVIGATION messages contained within NAVIGATION signals of the satellites. The NAVIGATION message describes position of the satellites both in space and in time. Combined processing of the measurements and the NAVIGATION messages of the four (three) GLONASS satellites allows user to determine three (two) position coordinates, three (two) velocity vector constituents, and to refer user time scale to the National Reference of Coordinated Universal Time UTC(SU).

10 The data ensuring of sessions scheduling for navigational determinations, selection of working "constellation" of SVs and detection of radiosignals transmitted by them, are transmitted as a part of the NAVIGATION message. Edition 2008 ICD L1, L2 GLONASS Russian Institute of Space Device Engineering 2. GENERAL The section 2 contains the definition of the Interface Control Document (ICD), procedure of approval and revision of ICD, and the list of organizations approving this document and authorized to insert additions and amendments to agreed version of ICD. ICD definition The GLONASS Interface Control Document specifies parameters of interface between GLONASS space segment and user equipment in L1 and L2 Bands ICD approval and revision The Russian Institute of Space Device Engineering (RIS DE) is a developer of the GLONASS satellite onboard equipment, being considered as a developer of control interface, is responsible for development, coordination, revision and maintenance of ICD.