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Fujimura T.,NEC Corp | Imai N.,NEC Corp | Seino Y.,NEC Corp | Kimura T.,NEC Corp | And 2 more authors.
Proceedings of the 2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2015 | Year: 2015

The new small airborne SAR for disaster monitoring was developed based on the technology of Pi-SAR2 of NICT. The summary of its development was reported in IGARSS 2013 and 2014 [1][2] and will be reported in IGARSS 2015 [3]. This paper reports the evaluation of its disaster monitoring capability using the change detection by the simple amplitude difference method. © 2015 IEEE.


Miyawaki M.,NEC Aerospace Systems Ltd. | Kimura T.,NEC Corp
International Geoscience and Remote Sensing Symposium (IGARSS) | Year: 2013

ScanSAR ScanSAR differential interferometric technique is a very powerful tool in order to detect the wide crustal deformation caused by huge earthquakes. © 2013 IEEE.


Maejima H.,Japan Aerospace Exploration Agency | Sasaki S.,Japan Aerospace Exploration Agency | Akagi C.,Asuka Denki Ltd. | Kobayashi H.,NEC Aerospace Systems Ltd. | Ohkami Y.,Keio University
Journal of Spacecraft and Rockets | Year: 2013

KAGUYA was a Japanese large lunar explorer that orbited and observed the moon from 2007 to 2009. During in-orbit operation, unexpected fluctuations and lock-offs of KAGUYA's uplink radio frequency telecommand signal were sometimes observed. To investigate the cause of the fluctuations, archived telemetry data were surveyed, and the telemetry data that showed the fluctuation were extracted. According to fault tree analysis of the telemetry data, multipath interference from the lunar surface and the spacecraft structure was deemed the most probable cause. This finding was verified by geometrical analysis of multipath interference. On the basis of the analysis results, the fluctuationmapfor a lunar polar orbiter was presented for the first time. Thismapwas used to avoid the telecommand operation failure of KAGUYA. This lesson can be generally applied to operations of planet and lunar orbiters.


Sawamura T.,NEC Aerospace Systems Ltd. | Takahashi T.,NEC Corp | Moriguchi T.,NEC Corp | Ohara K.,NEC Engineering Ltd. | And 3 more authors.
Institute of Navigation International Technical Meeting 2012, ITM 2012 | Year: 2012

The Quasi-Zenith Satellite System (QZSS), a Japanese satellite navigation system, broadcasts GPS-interoperable signals and augmentation signals as well as original Japanese signals from an inclined elliptical geosynchronous orbit. Using this system, users around Japan and Oceania can make use of seamless positioning, navigation, and timing services, even in urban canyons and mountainous areas, [1]. The first satellite of the Quasi-Zenith Satellite System, MICHIBIKI, was successfully launched on September 11, 2010, by a Japanese H2A launch vehicle is operating successfully. In-Orbit Checkout was conducted by the government sector, consisting of four ministries, National Institute of Information and Communications Technology, (NICT), National Institute of Advanced Industrial Science and Technology (AIST), Geospatial Information Authority of Japan (GSI), Electronic Navigation Research Institute (ENRI), and JAXA (Japan Aerospace Exploration Agency), and was completed successfully. From the middle of December, 2010, JAXA changed the navigation signals to the standard code. The technical verification and the application demonstration were also conducted and successfully finished in June 2011, [2]. NEC Corporation is responsible for the total system, QZSS, the ground system, and the on-board payload, QZS Navigation Payload (NP). In this paper, the in-orbit performance of the navigation performance of QZSS and L-Band Navigation Payload of QZS-1 are described.


Watanabe S.,Defense Systems | Hirao A.,NEC Aerospace Systems Ltd.
NEC Technical Journal | Year: 2011

The Advanced land Observation Satellite "DAICHI"(ALOS) is one of the world's largest class earth observation satellite launched on January 24, 2006. The primary mission of "DAICHI" is obtaining enormous volume of image data for global topographic mapping and emergency disaster monitoring of the disaster-struck area. It has three remote sensing instruments (PRISM, AVNIR-2 and PALSAR) for the precise ground surface observation. This paper describes practical applications of the images obtained via the three remote sensing instruments over the five year period subsequent to the launch and the ways that the obtained data may contribute to the social infrastructures affecting the lives of the people both inside and outside Japan.

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