GPS World, August 2015

THE ALMANAC Notes IGSO node longitudes are nominal values Nodes are allowed to drift 3 degrees or so A Inactive B Initially achieved geostationary orbit at a longitude of about 845 E but appears to have become uncontrollable shortly thereafter Librating about the 75 E libration point C GEO formerly at 1445 E shifted to 140 E between about June 30 and July 9 2011 D GEO formerly at 84 E shifted to 1105 E between about Nov 7 and Nov 23 2012 E The MEO satellites are in a 24 satellite three orbit plane Walker constellation with orbit planes spaced by 120 The first four MEO satellites occupy slots 7and 8 in plane 1 and slots 3 and 4 in plane 2 F Satellite is not currently transmitting G Satellite was launched at 13 52 UTC on March 30 2015 Not yet transmitting standard signals Notes BeiDou Constellation SATELLITE NORAD ID PRN LAUNCHED ORBIT NOTES BeiDou M1 31115 C30 4 13 07 MEO period 1289 hours A BeiDou G2 34779 N A 4 14 09 GEO drifting B BeiDou G1 36287 C01 1 16 10 GEO 140 E C BeiDou G3 36590 C03 6 2 10 GEO 1105 E D BeiDou IGSO1 36828 C06 7 31 10 IGSO 118 E 550 incl BeiDou G4 37210 C04 10 31 10 GEO 1600 E BeiDou IGSO2 37256 C07 12 17 10 IGSO 118 E 550 incl BeiDou IGSO3 37384 C08 4 9 11 IGSO 118 E 550 incl BeiDou IGSO4 37763 C09 7 26 11 IGSO 95 E 550 incl BeiDou IGSO5 37948 C10 12 1 11 IGSO 95 E 550 incl BeiDou G5 38091 C05 2 24 12 GEO 5875 E BeiDou M3 38250 C11 4 29 12 MEO period 1289 hours E BeiDou M4 38251 C12 4 29 12 MEO period 1289 hours E BeiDou M5 38774 C13 9 18 12 MEO period 1289 hours E F BeiDou M6 38775 C14 9 18 12 MEO period 1289 hours E BeiDou G6 38953 C02 10 25 12 GEO 80 E BeiDou I1 S 40549 3 30 15 IGSO 95 E 550 incl G standard signals BeiDou System Information China fielded a demonstration regional satellite based navigation system known as BeiDou Chinese for the Big Dipper asterism and pronounced bay dough following a program of research and development that began in 1980 The initial constellation of three geostationary Earth orbit GEO satellites was completed in 2003 A fourth GEO satellite was launched in 2007 The initial regional BeiDou system BeiDou 1 has been replaced by a global system known as BeiDou 2 or simply BeiDou and formerly Compass It will eventually include five GEO satellites 27 medium Earth orbit MEO satellites and five inclined geosynchronous orbit IGSO satellites BeiDou 2 was declared operational for use in China and surrounding areas on Dec 27 2011 FOC for this area was declared on Dec 27 2012 The system will provide global coverage by 2020 or even as early as 2017 according to some reports For more information Official BeiDou website English language version http en beidou gov cn IRNSS Constellation According to the Indian Space Research Organisation the Indian Regional Navigation Satellite System IRNSS will consist of three GEO satellites located at 34 E 83 E and 1315 E as well as two pairs of IGSO satellites with their nodes at longitudes of 55 E and 1115 E with an orbital inclination of 29 The satellites will transmit signals at 117645 and 2492028 MHz The first satellite in the planned constellation IRNSS 1A was launched from the Satish Dhawan Space Centre on July 1 2013 at 18 11 UTC The satellite with international designation 2013 034A and NORAD JSpOC identification number 39199 achieved its assigned IGSO on July 18 2013 with a nominal nodal longitude of 55 E and an orbital inclination of 27 Test transmissions started shortly thereafter The second IGSO satellite IRNSS 1B was launched on April 4 2014 at 11 44 UTC Designated as 2014 017A and 39635 it was placed in an orbit with a nominal nodal longitude of 55 E and an inclination of 31 The first GEO satellite IRNSS 1C was launched on Oct 15 2014 at 20 02 UTC Designated as 2014 061A and 40269 it is in a nominally geostationary orbit with a longitude of 83 E IRNSS 1D the third IGSO satellite was launched on March 28 2015 Designated as 2015 018A and 40547 it was placed in an orbit with a nominal nodal longitude of 1115 E and an inclination of 30 For more information ISRO website http www isro org satellites navigationsatellites aspx THE IRNSS 1D satellite LAUNCH OF BEIDOU I1 S on March 30 A Inmarsat 3 F2 began Safety of Life Service on March 2 2011 and is transmitting message type 2 B Astra 5B was launched on March 22 2014 and started transmitting L1 test signals on Dec 11 2014 C Decomissioned for EGNOS use Satellite sold to Britains Avanti Communications D Inmarsat 4 F2 began Safety of Life Service on March 22 2012 and is transmitting message type 2 E SES 5 also known as Sirius 5 and Astra 4B was launched on July 9 2012 Satellite occasionally transmits test signals F GSAT 8 was launched on May 20 2011 G GSAT 10 was launched on Sept 28 2012 H GAGAN was certified for enroute navigation and non precision approaches on Dec 30 2013 I MSAS commissioned for aviation use on Sept 27 2007 Either satellite can transmit both PRN signals if necessary J QZS 1 nicknamed Michibiki transmits an L1 augmentation signal using PRN code 183 That signal is in test mode Central longitude can vary by 5 or more from nomimal value K Luch 5A was launched on Dec 11 2011 Initially positioned at 585 E it was shifted to 95 E between about May 30 and June 28 2012 then shifted to 167 E between about Nov 30 and Dec 22 2012 Transmissions as PRN 140 began on July 12 2012 Transmitted occasional non coherent code carrier test signals L Luch 5B was launched on Nov 2 2012 and started transmitting test signals on Jan 17 2013 M Luch 5V was launched on April 28 2014 Testing may have started using PRN 140 not 141 N Galaxy 15 ranging supports enroute through precision approach modes Switched to backup satellite oscillator on Jan 6 2012 O Anik F1R ranging supports enroute through precision approach modes P The Galaxy 15 and and Anik F1R payloads operated by Lockheed Martin for the FAA are known as LMPRS 1 and LMPRS 2 respectively Q Inmarsat 4 F3 supports non precision approach ranging service Satellite Based Augmentation Systems SBAS SATELLITE ORBIT LONGITUDE PRN SIGNALS NOTES EGNOS Inmarsat 3 F2 AOR E 155 W 120 L1 A Astra 5B 315 E 123 L1 L5 B Artemis 215 E 124 L1 C Inmarsat 4 F2 25 E 126 L1 D SES 5 5 E 136 L1 L5 E GAGAN GSAT 8 55 E 127 L1 L5 F H GSAT 10 83 E 128 L1 L5 G H MSAS MTSAT 1R 140 E 129 L1 I MTSAT 2 145 E 137 L1 I QZSS QZS 1 135 E 183 L1 J SDCM Luch 5A 167 E 140 L1 K Luch 5B 16 W 125 L1 L Luch 5V 95 E 141 L1 M WAAS Intelsat Galaxy 15 CRW 133 W 135 L1 L5 N P TeleSat Anik F1R CRE 1073 W 138 L1 L5 O P Inmarsat 4 F3 AMR 98 W 133 L1 L5 Q GPS World August 2015 www gpsworld com 48