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Volume 38 (1999)
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Predecessor
Volume 38, Issue 4
Displaying 1-13 of 13 articles from this issue
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[in Japanese]1999 Volume 38 Issue 4 Pages 1
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
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[in Japanese], [in Japanese], [in Japanese]1999 Volume 38 Issue 4 Pages 2-3
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
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Qong Muhtar1999 Volume 38 Issue 4 Pages 4-16
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSThe purpose of this paper is to evaluate JERS-1 SAR data for determining vegetation types in arid regions. First, a noise speckle filter was applied to the original JERS-1 SAR image using a Map Filter with an adaptive 7×7 window. Multitemporal SAR images were registered with the JERS-1 OPS image using a secondorder polynomial function. The accuracy of registration was within 0.5 pixel RMS error. Second, a small part of the study area was extracted from the fullscene image for further analysis. The NRCS values of each extracted image were computed with the known Calibration Factor for the NASDA supplied JERS-1 SAR data. In order to smooth SAR imagery, focal operation was used. This operation provides a mean filter function for computing the values to replace noisy pixels in an image.
The resultant image was smoother than prior to filtering. Therefore, pixel values were smoothed to some extent with surrounding pixels. Their tones were thus somewhat simplified after filtering. Following this color composite, an image based on three scenes above was generated to identify the training samples (signatures) . Multitemporal color composite image was evaluated for vegetation type discrimination using supervised and unsupervised classification algorithms. As a result, two thematic layers were generated. Finally, the accurately classified classes from both of the classification results were gathered to obtain the final classification result. A test site along the Tarim River in the Tarim Basin, China, was selected for this purpose.View full abstractDownload PDF (6377K) -
Kohei ARAI, Manabu ARAKAWA, Hirofumi ETOH1999 Volume 38 Issue 4 Pages 17-25
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSA method for fuzzy retrievals of Earth observation satellite image database using geophysical parameters and spatial featuresis proposed. It is confirmed that the proposed method allows fuzzy expressions of queries with sea surface temperature, chlorophil-a concentration and cloud coverage as well as circle, line and edge, for instance “rather cold sea surface temperature AND a sort of circle feature”. Thus users, in particular, oceanographers may access the most appropriate image data from the databse for finding of cold cores (circle feaures), fronts (arc and line features), etc. in a simple manner.View full abstractDownload PDF (6389K) -
Ryuzo YOKOYAMA, Michio SIRASAWA, Yu KIKUCHI1999 Volume 38 Issue 4 Pages 26-34
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSOverground-openness and undergroundopenness are defined for a grid point on digital elevation models. The former is a characteristic quantity to describe sky extent over the point within a distance L and takes large values for convex landf orms. The latter is to describe underground extent and takes large values for concave landforms. These concepts are applied to 50m-mesh digital elevation model of Mt. Iwate to make openness maps of L=5km and L=0.5km. The maps were found useful to represent topographical features such as the lines of ridge and valley.View full abstractDownload PDF (8852K) -
Yoshio AWAYA, Nobuhiko TANAKA1999 Volume 38 Issue 4 Pages 35-46
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSReflectance factors were estimated using 8 Thematic Mapper images, and seasonal spectral changes of deciduous and evergreen cool temperate forests were examined from the reflectance factors. Our findings were as follows. 1) The seasonal changes were similar in channel 1 (blue) and 3 (red) in each forest. Deciduous forests had higher reflectance factors during the defoliated periods in early spring and late autumn. However, the reflectance factors decreased in the growing season due to the presence of green leaves. Evergreen forests showed stable reflectance factors from early spring until late autumn. 2) In deciduous forests, the highest reflectance factors in channel 2 (green) appeared in late spring. In evergreen forests, the reflectance factors in channel 2 and 4 (near infrared) peaked at the same time. 3) The reflectance factors in channel 4 increased greatly in late spring, and started to drop in mid-summer. Leaf development may appear most clearly in this channel. 4) In evergreen forests, reflectance factors in channel 5 (middle infrared) were highest in mid-summer and lower in early spring and late autumn. In deciduous forests, reflectance factors in channels 5 and 7 (middle infrared) were higher in late spring and decreased until just before defoliation.View full abstractDownload PDF (3194K) -
Kohei ARAI, Hirofumi ETOH, Tomoko NISHIYAMA1999 Volume 38 Issue 4 Pages 47-52
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSA search engine based on knowledge based system which allows Fuzzy expression of queries is proposed. A prototype system is created and tested. The results show that the system accepts a Fuzzy expression of query as well as a comprehensive dialogues between users and the system.View full abstractDownload PDF (507K) -
Eihan SHIMIZU, Takashi SHIDOJI, Takashi FUSE1999 Volume 38 Issue 4 Pages 53-58
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSHigh resolution and continuous images at the same point can be acquired by stratospheric platforms. The stratospheric platform has great potential with wider scope of utilization. For instance, the stratospheric platforms may provide measurement of traffic flow. In this study, we argue the possibility of vehicle tracking by stratospheric platforms, to be specific, we estimate displacement vectors of vehicles by applying the probabilistic relaxation method to time-series images. We improve the probabilistic relaxation method by (1) using the color information of vehicles, and (2) using the labeling of each other. The proposed method can be applied to appearance and disappearance of vehicles. Through the application to simulation data and sample image, we confirm the effectiveness of the proposed method.View full abstractDownload PDF (2899K) -
Chinatsu YONEZAWA, Shoji TAKEUCHI1999 Volume 38 Issue 4 Pages 59-64
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSBaseline distance of interferometric ERS-1/SAR data pair was estimated by orbital fringe pattern on the initial interferogram and digital elevation model without using ground control points and orbital information. The temporal changing pattern of baseline distance was simulated based on the assumption that orbital fringe patterns were divided into two patterns, one from parallel component of baseline distance and the other from perpendicular component of it. The interferogram of eastern Saitama prefecture, in which orbital and topographic fringes were removed, indicated local phase difference change patterns. Most of them corresponded to fine leveling results. This study suggested that land subsidence detection on urban area is possible by C-band SAR interferometry.View full abstractDownload PDF (3022K) -
Hiroshi MASAHARU, Hiroyuki HASEGAWA1999 Volume 38 Issue 4 Pages 65-68
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSA Method for extracting buildings and houses from high density elevation data obtained by a scanning laser ranging instrument carried on a helicopter has been developed by applying region segmentation to the elevation data. Boundary data of building polygons are obtained from the labeled images. With this method, building data for digital map data can be generated through automatic processing of the laser scanner data in principle, although the results show deformation due to remaining positioning errors in the original data.View full abstractDownload PDF (4902K) -
[in Japanese]1999 Volume 38 Issue 4 Pages 69-70
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSDownload PDF (223K) -
[in Japanese]1999 Volume 38 Issue 4 Pages 71
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
JOURNAL FREE ACCESSDownload PDF (79K) -
[in Japanese]1999 Volume 38 Issue 4 Pages 75-79
Published: September 02, 1999
Released on J-STAGE: March 19, 2010
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