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Jump to: Mission Objectives, Mission Instrumentation, Mission Parameters, Additional Information

Mission Photos:
QZSS satellite

QZSS satellite (Courtesy of Cabinet Office, Government Of Japan)

Mission Objectives:

The Quasi-Zenith Satellite System (QZSS) is a Japanese satellite navigation program planning for a future evolution to the regional satellite navigation system in East Asia and Oceania. A two stage system deployment is planned. In the first step, is the launch of a single satellite (QZS-1) in 2009 for technical validation and application demonstration. The second step involves the launch of the second and third satellites several years later to demonstrate full system operation. JAXA and related research institutes are in charge of technology development and demonstration of GPS complement and augmentation from QZSS.

QZSS is a four satellites constellation where each satellite is placed in the different orbital planes with inclined, geo-synchronous period and slight eccentricity. Each satellite is allocated in an orbit so as to pass over the same ground track at constant intervals with at least one satellite in place near zenith over Japan. QZS-1 was launched in 2009 by H-IIA launch vehicle from Tanegashima Space Center in Japan.

The QZSS has complete interoperability with GPS and will be worked as a GPS satellite with better geometrical position. QZSS will improve availability and DOP compared with use of GPS only, especially in urban canyon and mountainous terrain. The satellite system is also a good platform for WDGPS (Wide-area Differential Global Positioning System). High elevation angle characteristics can be applied to the WDGPS platform for stable link.

QZS-1 precise orbit ephemeris will be transmitted through the QZS-1 Navigation Message in the same way as is currently done in GPS. JAXA will perform QZS-1 precise orbit determination using L-band Navigation data received at monitor stations. The target accuracy of SIS-URE (radial direction) is several tens centimeters. SLR of QZS-1 is necessary to estimate navigation data biases and evaluate orbit determination accuracy.

NOTE: In February, 2017, responsibility for the QZSS transitioned from JAXA to the Cabinet Office, Government of Japan.

Mission Instrumentation:

QZS-1 has the following scientific instruments:

  • Radiation Cooled TWT
  • Laser Reflector
  • C-band TTC, L1-SAIF, L-band Helical Array, and TWSTFT Antennas
QZSS Mission Parameters:
Satellite QZS-1 QZS-2 QZS-3 QZS-4
Sponsor: Cabinet Office, Government of Japan Cabinet Office, Government of Japan Cabinet Office, Government of Japan Cabinet Office, Government of Japan
Expected Life: 12 years 15 years 15 years 15 years
Primary Applications: Satellite navigation Satellite navigation Satellite navigation Satellite navigation
Primary SLR Applications: Calibration of GPS orbits Calibration of GPS orbits Calibration of GPS orbits Calibration of GPS orbits
COSPAR ID: 1004501 1702801 1704801 1706201
SIC Code: 1581 1582 1583 1584
Satellite Catalog (NORAD) Number: 37158 42738 42917 42965
Launch Date: 11-Sep-2010 01-Jun-2017 19-Aug-2017 10-Oct-2017
NP Bin Size: 300 seconds 300 seconds 300 seconds 300 seconds
RRA Diameter: 1.6" 1.6" 1.6" 1.6"
RRA Shape: Planar Planar Planar Planar
Reflectors: 56 corner cubes 56 corner cubes 56 corner cubes 56 corner cubes
Altitude: 32,000-40,000 km 32,000-40,000 km 36,000 km 32,000-40,000 km
Inclination: 45 degrees 45 degrees 0 degrees 45 degrees
Orbit: Elliptical Elliptical Geosynchronous Elliptical
Eccentricity: 0.075 0.075 0 0.075

Additional Information:

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