QZSS (quasi-zenith satellite system) is a Japanese satellite navigation program with a regional service coverage. The orbits for QZS are 24-hour elliptic orbit inclined 45 degrees in order to broadcast radiosignals from high elevation angle into urban canyons. The first QZSS satellite was launched successfully on 11th Sept from Tanegashima Space Center, Japan. QZSS will broadcast GPS augmentation information as well as ranging signals on the GPS L1 frequency. For this purpose L1-SAIF (submeter-class augmentation with integrity function) signal has been developed by the ENRI. L1-SAIF augmentation messages are generated at L1-SAIF Master Station (L1SMS) and broadcast to the experimental area via QZSS. All facilities including L1SMS and QZSS master control station have been installed properly and completed integration test. The experiment with the first QZSS satellite will begin after functional checkout by the end of November. Summary Development of QZSS L1-SAIF Augmentation Signal Takeyasu SAKAI, Sonosuke FUKUSHIMA, and Ken ITO Electronic Navigation Research Institute QZS GPS/GEO Signal from high elevation angleSignal from high elevation angle Applicable to navigation services for mountain area and urban canyonApplicable to navigation services for mountain area and urban canyon Footprint of QZS orbitFootprint of QZS orbit Centered 137ECentered 137E Eccentricity 0.1, Inclination 45degEccentricity 0.1, Inclination 45deg QZSS Concept: Navigation signal from high elevation angle Function distributed in each institute Timing management by NICT, WADGPS service by ENRI, etc. SLR Site Monitor Station NW GPS Satellites TT&C / NAV Msg Uplink Station GEONET (GSI) Time Mgmt Station TWSTFT: Two Way Satellite Time and Frequency Transfer QZS Satellite User Receiver Satellite Laser Ranging Navigation Signals L1: MHz L2: MHz L5: MHz LEX: MHz TT&C / NAV Message Uplink TWSTFT Up: GHz Down: GHz (Courtesy: JAXA QZSS PT) Master Control Station (MCS) Overall Architecture L-band Helical Array Antenna L1-SAIF Antenna Laser Reflector C-band TTC Antenna Radiation Cooled TWT TWSTFT Antenna 25.3m Mass Approx. 4,000kg (NAV Payload ： Approx. 320kg) Power Approx. 5.3 kW (EOL) (NAV Payload: Approx. 1.9kW) Design Life10 years (c) 三菱重工業 QZS-1 Satellite “Michibiki” Successfully Launched at 20:17 of Sept. 11, 2010 from Tanegashima Space Center; Now initial checkout in progress; First navigation signals successfully broadcast since Oct. 19. Storage Router to GEONET I/F UPS Message Generator GEONET Server Storage Ionosphere Processor Storage L1-SAIF Master Station (L1SMS) at ENRI With L1-SAIF GPS only User Receivers L1-SAIF (Submeter-class Augmentation with Integrity Function) augmentation signal provides: (1) Differential Correction information improving position accuracy; Target accuracy = 1 m; (2) Integrity information for ensuring reliability of position information; (3) An additional ranging source to improve availability of satellite constellation. User receiver do not need additional antenna and/or RF circuit to receive L1-SAIF signal due to its compatibility with the GPS signal; ENRI has been involved the program and developing L1-SAIF. L1-SAIF Ranging L1-SAIF Correction L1-SAIF Integrity QZS satellite GPS Satellites Ranging Signal L1-SAIF Augmentation Signal User position error measured at GEONET site (Takayama at the center of Mainland of Japan); Period: Jan. 19 to 23, 2008 (5 days). Horizontal Error Vertical Error 1.45 m2.92 m 6.02 m8.45 m System GPS Only 0.29 m0.39 m 1.56 m2.57 m Augmented by L1-SAIF RMS Max RMS Max NOTE: This result is obtained by the survey grade antenna and receiver. L1SMS Realtime Operation Test Result