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Volume 2 (1982)
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Volume 2, Issue 4
Displaying 1-8 of 8 articles from this issue
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T. Takashima, Y. Takayama1982 Volume 2 Issue 4 Pages 3-26
Published: December 20, 1982
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSMethods of deriving the sea surface temperature from space are described in the infrared region of spectrum. This spectral region corresponds to the infrared channels of the Advanced Very High Resolution Radiometer (AVHRR) on board the NOAA-6 satellite. Thus the deviation of the sea surface temperature (SST) from the computed temperature by the use of the model atmosphere bounded by the ocean surface was evaluated for both daytime and night orbits. In the atmosphere the effect of cloud, water vapor, carbon dioxide, nitrogen molecule, methane and aerosols were taken into account, in addition to the surface emissivity which depends upon the ocean surface state. The brightness temperature measured by satellite represents that of a skin surface of water within a depth of a few microns. Hence this temperature is not always corresponding to that of ship data. The ship measures the temperature of a bulk water in a bucket. To find out the relationship between the brightness temperature by a radiometer and the real water temperature, measurements of water temperature was carried out at the water pool installed outside the Meteorological Research Institute under the various weather conditions.
Finally the data utilization of water vapor absorption band of 6-7μm and infrared window region ranging from 8 to 9μm, whose wavelength regions are not available on AVHRR radiometer, are evaluated.View full abstractDownload PDF (1281K) -
Sotoaki Onishi1982 Volume 2 Issue 4 Pages 27-43
Published: December 20, 1982
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSFluid dynamic characteristis of jet, which is one of interesting topics in turbulent flow research, have been studied by many reseachers.
Although recent some trials to apply coherent vortex structure theory on the study of turbulent jet are considered being interest to the author, it is considered that almost all exsisting researches are either theoritical or experimental ones. In this paper, the author tries to indicate some derterministic features of the turbulent buoyant jet as well as non-buoyant jet in straits and coastal zones by remote sensing including aero photograph, colour analysis of sound echo and Landsat data analysis. Physical model studies are also introduced to supplement the analyses.
With analysis of field observation data of tidal jet in Naruto strait, the anthor shows that dynamic vortices shall be generated along shear layers when the jet strouhal number at the end of potential core is of 0.2 through 0.5. The colour sonar analysis shows definitely vertical profiles of the above coherent vortices. With regarding to the jet characteristics in the far field, Landsat data of several buoyant jets discharged into Japan sea from rivers including Shyo, Kuzuryu, Tedori and Mogamic are discussed.View full abstractDownload PDF (7777K) -
Akira Tsuboi, Tetsuji Iijima, Hiroshi Kimura, Nobuhiko Kodaira1982 Volume 2 Issue 4 Pages 45-56
Published: December 20, 1982
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThe synthetic aperture radar (SAR) images produced from the Seasat SAR data have provided useful all-weather topographical information. In order to produce a SAR image, the raw data is compressed by the action of matched filters, first in the range direction, then in the azimuth direction. The estimation error in a coefficient of the azimuth matched filter, called Doppler rate, causes image slip between looks. The image slip gives rise to most degradation of SAR multi-look image in look summation operation.
In order to reduce the degradation and produce a high resolution SAR multi-look image, an image slip detection type auto-focusing will be effective on condition that the precisely measured image slip data is given.
One of the conventional image slip measurement method is based on the cross-correlation between two looks of one scene. But, it is dependent on the characteristics of the scene.
This paper describes an improved method called three looks correlation. In this method, the measurement error is reduced by measuring and selecting the image slip among three looks of various scenes. The results of the Doppler rate auto-focusing tests show that the proposed method can reduce the measurement error by half in comparison with the conventional one.View full abstractDownload PDF (1779K) -
Junji SUYAMA, Yoshinori ISHII, Yasushi YAMAGUCHI, Hiroki KAMATA, Hirok ...1982 Volume 2 Issue 4 Pages 57-65_9
Published: December 20, 1982
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThis paper reviews the method and results of the airborne SAR survey which was conducted by NEDO (New Energy Development Organization) as a part of the Nation-Wide Geothermal Survey Project. The whole Japanese Islands except IzuOgasawara Islands were covered by non-stereo/west-look SAR images. In addition to this, main geothermal area was covered by non-stereo/northlook images and Izu peninsula was covered by stereo/north and west-look images. The SAR holographic date was processed through an optical correlator to present the mosaic image of scale 1 : 200, 000. The geological and geothermal interpretation of the images are now under progress.
This paper presents several SAR images as well as maps produced from SAR images. Some technical problems arisen during the data acquisition (flight) are also presented.View full abstractDownload PDF (15985K) -
Kazuaki TAKAO, Eiji HIRATA, Yasushi AYAKI, Yasumasa HISADA, Yasuyuki I ...1982 Volume 2 Issue 4 Pages 67-74
Published: December 20, 1982
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSA set of ground experiments were carried out at Tsukuba Space Center in November and December, 1981. Data were processed and analyzed in order to determine the parameters for system design. Choice of the SA ratio which is related with the size of the antenna, how much SN ratio is necessary, and how many bits are required to quantize and transmit the data are the items that are investigated. Also, the effect of the correction due to the information of the position and attitude of the radar system are verified by the intentionally erroneous experiment which is to be compensated with data processing.View full abstractDownload PDF (368K) -
[in Japanese], [in Japanese]1982 Volume 2 Issue 4 Pages 75-91_1
Published: December 20, 1982
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSDownload PDF (9786K) -
1982 Volume 2 Issue 4 Pages 93-110
Published: December 20, 1982
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSDownload PDF (4846K) -
1982 Volume 2 Issue 4 Pages 113
Published: 1982
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSDownload PDF (22K)
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