Quasi-Zenith Satellite System
The Quasi - Zenith Satellite System ( QZSS ) is a building under construction Japanese satellite system, to complement the global navigation satellite systems (GNSS). The satellite constellation of three geosynchronous satellite was designed specifically for Japan, but also other Asia -Pacific regions will benefit from it.
Basic principle
The three or even more satellites are orbiting the Earth in a highly elliptical orbit with an orbital period of one sidereal day and a web height of between 32,000 km and 40,000 km. The orbital inclination will amount to 43 °, so that at any time one of the satellite is directly over Japan ( almost at the zenith ). This increases especially in cities and in mountainous terrain, the probability that along with the satellites of other GNSS position determination is possible and the light emitted from the QZ- satellite Additional information can be received.
The QZSS is similar to the other GNSS and consists of the space segment, a control segment (Master Control Station and several observation stations ) and the User Segment ( receivers ).
The space segment will be equipped with GPS complementary and experimental equipment, and send signals equivalent to the modern GPS. This ensures compatibility and interoperability should be ensured between the systems. Send QZ satellites existing L1-C/A- and L2 -C - GPS signals, the future L5 and L1 C-GPS signals, as well as a signal with a higher data rate experiment called LEX, which at the same frequency as the Galileo E6 signal is transmitted. In addition, another called L1-C/A-Signal QZS L1 SAIF is emitted, which is compatible with the signals of the existing SBAS. SAIF stands for " submeter -class Augmentation with Integrity Function". This signal contains additional information about the integrity of GPS signals and correction data for improving the accuracy of the GPS system.
Development
The Quasi - Zenith Satellite System is a joint project of public institutions and private sector companies ( Public Private Partnership). From Government head four state ministries, the investigation and development of technology, in the private sector takes place the commercial planning of the commercial ( profit plan) and the structure and the financing of broadcasting and communications system. The Japanese space agency JAXA integrates research institutes in the development process.
The structure of the system is gradually according to the State Decree of 31 March 2006. In August 2008, the system design review (Critical Design Review ) was completed, so that could be the first satellite QZS -1 produced and tested.
Satellite
The launch of the first satellite called QZ- Michibiki (みちびき, "Guidelines, leadership " ) took place on September 11, 2010 from Tanegashima Space Center with an H- IIA F-18 launcher. The satellite is about 4 tons in weight and is 2.9 m long, 3.1 m wide and 6.2 m high. The two solar boom together have a span of 25.3 m. Japan plans before 2020Vorlage: Future / bring in five years, three more satellites into space.