Japan launched its second Multi-Functional Transport Satellite (MTSAT-2) on February 18, opening a new phase of precision air navigation and air traffic control (ATC) over the western Pacific Ocean.
Japan launched its second Multi-Functional Transport Satellite (MTSAT-2) on February 18, opening a new phase of precision air navigation and air traffic control (ATC) over the western Pacific Ocean.
The five-ton spacecraft — the heaviest flown by Japan — will operate at a 22,300-mile altitude in a circular geostationary orbit. From that location, on-board transponders will provide another link for Japan’s MTSAT Space-based Augmentation System (MSAS), relaying differential GPS corrections and integrity messages to suitably equipped users. The first satellite in the MSAS space segment, MTSAT-1R, went into orbit a year earlier.
Chief among the MSAS beneficiaries will be aircraft operating transoceanic routes across the Pacific. The improved navigation accuracy and associated communications links will allow planes to operate closer together along the most traveled routes.
In addition to the GPS navigation data, MSAS will provide datalinks to and from ATC control centers and enable the automatic transmission of aircraft locations to controllers when are out of range of ground-based ATC radars — a feature known as automatic dependent surveillance. Besides the L-band GPS broadcasts, MTSAT provides voice and data communications over Ku- and Ka-band frequencies.
MSAS operates in fashion similar to the U.S. Federal Aviation Administration’s GPS Wide Area Augmentation System (WAAS) and provides a comparable service to the European Geostationary Navigation Overlay Service (EGNOS) operated by the European Space Agency.
An H-2A rocket carried MTSAT-2 into space from the Tanegashima space center. Its operators are the Japan Civil Aviation Bureau and the Japan Meteorological Agency. Once testing is complete, MTSAT-2 will operate permanently along the equator at 145 degrees east longitude and above the Micronesia region.
During its 10-year mission, MTSAT-2 will also serve as a weather observatory for Japanese forecasters, drawing on four infrared sensors and one in the visible wavelength. The spacecraft will also relay weather, seismic, and tidal reports from remote ground monitoring stations.
Copyright 2006 Gibbons Media and Research LLC
