Tsunekazu Kimura

A new small airborne SAR based on Pi-SAR2

This paper shows the summary of the development of a new small airborne SAR based on Pi-SAR2. In spite of the high performance similar to Pi-SAR2, its size will be approximately 20 % of Pi-SAR2 and it can be operated on light aircrafts. The current status of the development is the second year of 3 years of development term, which is the critical design and the prototype manufacturing phase.

The bistatic SAR experiment with ALOS / PALSAR and Pi-SAR-L

The first bistatic SAR experiment between Japanese spaceborne PALSAR and airborne Pi-SAR-L was successfully performed and gave an excellent image in 2010. This paper mainly reports the result of this bistatic SAR experiment and its data analysis. As the result of the analysis, two conclusions are confirmed. One is the success of the bistatic SAR observation without special functions for them and the other is the advantage of this bistatic SAR observation.

The digital wide band chirp pulse generator and processor for Pi-SAR2

This paper shows the technology and the performance of the digital wide band chirp pulse generator and processor for Pi-SAR2, and the history of its development at NEC. This chirp pulse generator and processor can generate the 150, 300 or 500MHz bandwidth chirp pulse and process the same bandwidth video signal. The offset video method is applied for this component in order to achieve small phase error, instead of I/Q video method for the conventional SAR system. Pi-SAR2 realized 0.3m resolution SAR image with the 500 MHz bandwidth using this component.

Development status of a new small airborne SAR based on Pi-SAR2

This paper shows the development status of a new small airborne SAR based on Pi-SAR2. We had designed its advanced small type high resolution full polarimetric airborne SAR with the real-time processor. Its flight test will be planned in this fiscal year.

Inertial stabilization system for small airborne SAR

An inertial stabilization system for small airborne synthetic aperture radar (SAR), which consists of an active damping mechanism and a two-axis gimbal, has been developed. Both high-frequency vibration isolation by the active damping and high stability of antenna direction under low-frequency angular disturbance have been successfully demonstrated. Also, a small airborne SAR prototype for disaster monitoring has been produced and prepared for flight tests.

Small optical sensor satellite “asnaro” and series of small earth observation satellites

This paper shows the new small optical sensor satellite “ASNARO” and series of small earth observation satellites. ASANRO is developed by NEC under the contract with the Japanese government and its launch is planned this December. This satellite is 500 kg class small size satellite with 0.5 m resolution optical sensor. In addition, we plan the development of small earth observation satellites with various sensors, such as Hyper-spectral sensor, X band SAR sensor and so on, based on the same technologies as ASNARO. These small satellites series will realize the high performance earth observation system with multi sensors.

Extraction of wide-ranging crustal movement using ALOS/PALSAR ScanSAR interferometry

In recent years, huge earthquakes have occurred in many places and those have induced the crustal movements over hundreds of kilometers. In such cases, the entire movement area cannot be observed with differential interferometric SAR processing using Stripmap mode data, because Stripmap mode of ALOS/PALSAR covers only 70km swath. On the other hand, ScanSAR is suitable for extraction of wide-ranging crustal movement caused by huge earthquake due to its wide coverage about 350km swath. Authors tried ScanSAR-ScanSAR differential interferometric processing using a lot of pairs of PALSAR ScanSAR mode data. We processed in two actual huge earthquake cases. One is the 2008 China Wenchuan earthquake (May 12 2008, Mw 7.9) case, and the other is the 2010 Chile earthquake (Feb. 27 2010, Mw 8.8) case. In this paper, the results of these two ScanSAR-ScanSAR differential interferometric SAR processing using PALSAR data are introduced. As a result, it is demonstrated that ScanSAR-ScanSAR differential interferomtry is a very powerful tool to detect the wide-ranging crustal movement caused by a huge earthquake.

Evaluation of detection capability of crustal movement by airborne SAR (PI-SAR-L2) repeat-pass interferometry

This paper reports the evaluation results of detection capability of crustal movement by an airborne SAR (Pi-SAR-L2) repeat-pass interferometry. Pi-SAR-L2 belongs to by JAXA (Japan Aerospace Exploration Agency). The object is to estimate the detection accuracy of crustal movement by Pi-SAR-L2.

Prospect of disaster monitoring with the new small airborne SAR

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.

Improvement of ScanSAR interferometric processing

ScanSAR ScanSAR differential interferometric technique is a very powerful tool in order to detect the wide crustal deformation caused by huge earthquakes. We tried to detect the crustal deformation caused by 2011 Japan Tohoku earthquake (March 11 2011, Mw 9.0) using the data of ALOS/PALSAR ScanSAR mode. We processed ScanSAR interferometry based on full aperture imaging method [1]. However, only poor interferogram was obtained, because of severe interferometric conditions and the steep terrain in processing area. In order to improve interferometric quality, we tried the interferometric processing using the time-domain back projection approach, and range and azimuth filtering. In this paper, the result of ScanSAR ScanSAR interferometry based on time-domain back projection method is reported.