Showing papers in "Journal of The Japan Society of Photogrammetry and Remote Sensing in 1998"
262 citations
TL;DR: In this article, the slope and inflection point position of the red edge reflectance feature was determined by calculating the first derivative of the spectral curve and a distinctive blue shift was seen in reflectance data from samples collected of the water deficient seedlings.
Abstract: Unusual weather during the summers of 1990's was detrimental to forests and crops. The scientists responsible for the observed forest decline have not been identified, and still trying to find the causes. In this study, measurements of leaf spectral reflectance, photosynthesis, and stomatal conductance of Stewartia pseudocamellia Maxim. (Natsutsubaki) seedlings were carried to detect an indicator of plant water status. Reflectance on infrared wavelength increased with decreasing leaf water content. The slope and inflection point position of the red edge reflectance feature was determined by calculating the first derivative of the spectral curve. A distinctive blue shift, defined here as a shift of the red edge inflection point to shorter wavelengths, is seen in reflectance data from samples collected of the water deficient seedlings. Stress index (SI) was also derived from leaf spectral reflectance data. The photosynthesis and stomatal conductance were affected by low water potential, and these parameters decreased with increasing SI value. The relationships between the physiological parameters of tree seedlings and SI derived from remote sensing data suggest that SI value is useful for detecting and monitoring stress status of forests.
20 citations
TL;DR: In this article, the authors attempted to detect their damages by ERS-1/SAR images obtained before and after the 1995 Hyogoken-nanbu earthquake by measuring the backscatter correlation coefficients.
Abstract: Large part of urban area of Kobe, Ashiya and Nishinomiya city were damaged by the 1995 Hyogoken-nanbu earthquake. The authors attempted to detect their damages by ERS-1/SAR intensity images. The intensity images obtained before the earthquake indicated urban structure clearly, however, the structural pattern was unclear in the images after the earthquake. Norm type correlation coefficients of data pair between before and after the earthquake indicated decorrelation at damaged urban area. The decorrelation by the earthquake was detected obviously in comparison with the correlation of the data pairs which interval did not include the earthquake occurrence. The areas where the backscatter correlation changed significantly before and after the earthquake correspond to damaged built-up areas observed by aerial photographs. The ground surface change by the earthquake, such as collapse or burnt down of buildings, should cause the change of backscatter characteristics and further study is necessary to investigate its mechanism. Collapsed built-up area has not been recognized by optical sensor images like SPOT/HRV. The result of this study suggests the usefulness of SAR intensity images for urban disaster observation.
7 citations
5 citations
TL;DR: In this article, a simple method for estimating the off-nadir distance is proposed based on the observation of the Landsat TM image which is normally processed by NASDA, and 120 ground control points are systematically selected, and their image coordinates and map coordinates are carefully measured.
Abstract: Accurate geometric correction including ortho-rectification is considered for Landsat TM imagery of large rugged terrain. Ortho-rectification requires off-nadir distance of satellite image and accurate digital elevation model. The digital elevation model published by the National Geographycal Survey are reprojected on the UTM coordinate system of the concerned region (Iwate Prefecture) with 30m spatial resolution. A simple method for estimating the offnadir distance are proposed based on the observation of the TM image which is normally processed by NASDA. For precise geometric transformation, 120 ground control points are systematically selected, and their image coordinates and map coordinates are carefully measured. Statistical analysis of the obtained points reveals that the errors both in pixel and line positions are less than 0.7 pixel if the relief displacement is removed, otherwise the error in pixel position increases by 0.3 pixel. These errors can be statistically explained by the pixel identification error (0.5 pixel), the digitizing error (0.3 pixel), and the relief displacement (0.6 pixel) . The ortho-rectified image is consistently overlaid on the map image.
4 citations
TL;DR: In this paper, two estimation models based on NDVI and TSAVI were applied to produce green vegetation cover images and compared with ground data collected in grasslands of Mongolia, showing that the estimate by TSAVI has better accuracy for the green vegetation coverage with low densities and NDVI performs better result for middle and high vegetation cover.
Abstract: NOAA Advanced Very High Resolution Radiometer (AVHRR) data were used to estimate green vegetation coverage of grasslands for semi-arid region. Two estimation models based on NDVI and TSAVI were applied to produce green vegetation cover images and compared with ground data collected in grasslands of Mongolia. There was significant agreement between ground data and the estimate of satellite data. The estimate by TSAVI has better accuracy for the green vegetation cover with low densities and the estimate by NDVI performs better result for middle and high vegetation cover. The result suggests that the joint use of the NDVI and TSAVI can improve accuracy of the estimate.
3 citations
TL;DR: In this article, the applicability of category decomposition method based on the linear mixture model for the fusion of multiple-resolution satellite data such as Landsat-TM and NOAA-AVHRR was tested.
Abstract: The authors tested the applicability of category decomposition method based on the linear mixture model for the fusion of multipleresolution satellite data such as Landsat-TM and NOAA-AVHRR. The goal of the application of this method is to estimate the mixing ratio of different categories within one pixel of the lower-resolution data using the classification result of the higher-resolution data, which is considered to be useful for the extrapolation of the information from the higher-resolution data over the wider coverage of the lower-resolution data. The authors tested the estimation accuracy by two kinds of decomposition methods, the maximum likelihood estimation and the minimum distance estimation and also by the multiple regression method. The experimental results showed that the most adequate estimation was obtained by the category decomposition based on the minimum distance estimation.
3 citations
TL;DR: In this article, a method for spatial resolution enhancement based on Maximum Entropy Method (MEM) with simulated annieling is proposed using overlap sampling with a low resolution of sensor, which can be achieved through ground data processing with image restoration methods.
Abstract: A method for spatial resolution enhancement based on Maximum Entropy Method (MEM) with simulated annieling is proposed. Using overlap sampling with a low resolution of sensor, high spatial resolution (corresponding to the sampling interval) can be achieved through ground data processing with image restoration methods. Through the experiments with simulation imagery data derived from AVHRR data, it was found that spatial resolution enhancement can be achieved, MEM is superior to the others when S/N is poor (less than 33) while Conjugate Gradient method is superior when the S/N is higher than 33. It was also found that the Conjugate Gradient method is superior to the proposed method for the existing sampling jitter.
2 citations
TL;DR: In this paper, the authors focused on the environmental impact of slash and burn on the forest ecology by mean of spatial and temporal analysis of high-resolution satellite data and used Geographic Information System (GIS) was also used for analyzing the relationship between the Slash and burn and forest vegetation, topography and social factors.
Abstract: There has been a large amount of slash and burn agricultural activity from ancient times in Northern Laos. This study focuses the environmental impact of slash and burn on the forest ecology by mean of spatial and temporal analysis of high resolution satellite data. A Geographic Information System (GIS) was also used for analyzing the relationship between the slash and burn and forest vegetation, topography and social factors. Then, the sustainability of slash and burn was examined by the ecological analysis of the shifting pattern and fallow duration derived from the image interpretation. As a result of study, a total of 89, 000 ha of slash and burn fields within 172, 000 ha of fallow lands were detected during the past 10 years. Although the recent increase of population pressure caused an expansion of slash and burn fields (11, 000 ha in 1987 to 19, 000 ha in 1997), most parts (80%) of those fields are still maintaining the traditional conditions of having more than 7 years fallow duration. It can be said that such slash and burn is sustainable because of its ecologically balanced cycle of cultivation. Based on the analysis, it is concluded that slash and burn agriculture is not always a cause of environmental deterioration in the study area. More important is the introduction of a well managed methodology of forest resources for future sustainable development. In this sense, it can be recommended that remote sensing and GIS technology play a more important role in the monitoring of slash and burn agricultural practices.
2 citations
2 citations
TL;DR: In this paper, the direct solar irradiation can be calculated with high geometrical accuracy by using a digital elevation model and the solar position, which can be applied to an actual Landsat/TM image to show its effectiveness.
Abstract: In rugged terrain, a digital number of satellite data is highly correlated with direct solar irradiation, which is propotional to the cosine of solar incident angle. The direct solar irradiation can be calculated with high geometrical accuracy by using a digital elevation model and the solar position. In this paper, we propose to use the calculated direct solar irradiation to determine ground control points (GCPs) for precise geometrical correction of the satellite imagery. The proposed method is applied to an actual Landsat/TM image to show its effectiveness.
TL;DR: By proposing a series of techniques based on combination of probabilistic relaxation method and gradient method, insensibility on setting parameters is achieved in individual methods and as a result total process is more robust.
Abstract: It is necessary for fully automatic relative orientation to realize precise and stable detection of tie points in stereo images. However, usual approaches such as template matching are not applicable to images of different conditions because parameters depend on features of images strongly. In this paper we proposed a series of techniques based on combination of probabilistic relaxation method and gradient method. By our approach, insensibility on setting parameters is achieved in individual methods and as a result total process is more robust. In addition, by examining detected points using relative orientation equation, it is possible to select points that satisfy required accuracy. The validity of proposed technique was verified by experiments using differently
TL;DR: A discovery of the buried Egyptian remains has been made by using satellite SAR data as mentioned in this paper, which was very similar to the characteristics of the existing Egyptian pyramids, was detected on a hilltop of Saqqara where nothing has been reported so far.
Abstract: A discovery of the buried Egyptian remains has been made by using satellite SAR data. L-band (HH) signal of SIR-C (Shuttle imaging Radar Mission-C), which was very similar to the characteristics of the existing Egyptian pyramids, was detected on a hilltop of Saqqara where nothing has been reported so far. As the result of the ground truth, some artificial lime stone blocks and significant fragments were found. The area is situated approximately 200m west of the pyramid of Merenre. This is a preliminary report of the study for satellite SAR application in Egypt.
TL;DR: This paper investigates the application of CMOS image sensor for digital photogrammetry and finds its applications in industry metrology, machine and robot vision, medical and sports science, archaeology, construction management and so on.
Abstract: The change in photogrammetry from analog to digital means a change from film to CCD sensor and real-time imaging became possible. In these circumstances, digital photogrammetry is expected to become a useful tool in various fields, e. g. industry metrology, machine and robot vision, medical and sports science, archaeology, construction management and so on.However, CMOS image sensor has recently received more attention from the points of view of cheap cost and low power consumption.This paper investigate on the application of CMOS image sensor for digital photogrammetry.
Abstract: Three dimensional position data of ground objects watched on a landsliding area can effectively and safely be obtained by aerial photogrammetry. These data acquired by several flights of different time are used to the least square algorithm that is constructed for presumption of the geometric shape of underground slide surface. This paper newly introduced two techniques into the analytic procedure. They are 1) estimation of the reliability of tracking points and boundary conditions, 2) connection condition of many different shapes of sliding group. Effects of these techniques are verified by numerical examples applied to the actual landslide areas having complicated shape of underground slide surface.
TL;DR: In this article, a nighttime OLS visible-near infrared (VNIR) channel image was overlaid on the simultaneously corrected OLS thermal infrared (TIR) image for the area around Japan.
Abstract: The OLS (Operational Linescan System) sensor on board the DMSP (Defense Meteorological Satellite Program) can observe the lights in the night. A nighttime OLS visible-near infrared (VNIR) channel image was overlaid on the simultaneously corrected OLS thermal infrared (TIR) channel image for the area around Japan. The OLS composite image showed a clear relationship between the location of fishing fleet lights detected by the VNIR channel and the sea surface temperature (SST) distribution observed by the TIR channel. Many fishing fleets were located at the cold side of boundary area of warm current and cold current. Since some types of fishes are likely to gather in certain sea temperature zones, the OLS composite image may provide useful information for the fishing fleets monitoring as well as for the marine resources management.
TL;DR: The proposed method achieved 25% of improvement of the compression factor compared to the existing method of Discrete Cosine Transformation with almost comparable image quality between both methods.
Abstract: An image data compression method based on the compression (DCT: Discrete Cosine Transformation) featuring an image restoration method is proposed. DCT image compression is widely used and has four major image defects. In order to reduce the noise and distiortions, the proposed method expresses a set of parameters for the assumed distortion model based on an image restoration method. The results from the experiment with Landsat TM (Thematic Mapper) data of Saga show a good image compression performance of compression factor and image quality. Namely, the proposed method achieved 25% of improvement of the compression factor compared to the existing method of Discrete Cosine Transformation with almost comparable image quality between both methods.
TL;DR: The outline of AMSS is introduced and the result of image quality check using Integrating Sphere and Black body is confirmed that the data of visible and near-infrared region has yet meet to the specifications and insufficient for scientific use.
Abstract: The Airborne Multi-Spectral Scanner (AMSS) is an airborne scanning spectrometer which provides spectral information similar to that which will be provided by the Global Imager (GLI) scheduled to be launched on the ADEOS-II platform in 2000. The AMSS acquires high spatial resolution imagery in the range of 0.40 to 12.45 microns, and a cross track scan width of +/- 35 degrees. This paper introduce the outline of AMSS and the result of image quality check using Integrating Sphere and Black body. As a result, it was confirmed that the data of visible and near-infrared region has yet meet to the specifications and insufficient for scientific use.
TL;DR: In this paper, a new method of correcting reflectance to remove undesirable variations from NDVI was proposed based on statistical time series analysis, which is a kind of time series model, and Kalman filter algorithm is applied for the estimation of surface reflectance.
Abstract: NDVI obtained from NOAA AVHRR is suitable for vegetation monitoring at global scale. However, NDVI values are affected not only by seasonal changes of vegetation but also by other factors, such as anisotropy of ground, cloud, and atmospheric effect. In this paper, we propose a new method of correcting reflectance to remove undesirable variations from NDVI. This method is based on statistical time series analysis. Simple BRDF model is modified to state space model, which is a kind of time series model, and Kalman filter algorithm is applied for the estimation of surface reflectance. The result of sample points shows the possibility of correcting the ground reflectance. And some are discussed for the further improvement.
TL;DR: In this article, the wave heights are estimated by using a composite-scattering model and the image wavenumber spectrum obtainable from SAR. And the wavelength and wave direction are also estimated by this spectrum.
Abstract: Ocean waves have been observed by the satellite remote sensing data operated at the microwaves. In particular, the surface capillary-gravity waves which are sensitive to the surface-wind stress and whose crest perpendicular represented as the wind direction are studied by many oceanographers and scientists. On the other hand, there are few papers of the gravity waves as a swell. But it is important that the motion of gravity waves were observed and studied because it is necessary to plan the disaster privation and make the environmental assessment in the coastal. Therefore, it makes a method of estimating the wave heights from the backscattering coefficients in the SAR images. In this method, the wave heights are estimated by using a composite-scattering model and the image wavenumber spectrum obtainable from SAR. In addition, the wavelength and wave-direction are also estimated by this spectrum. Finally, these values are good agreement with the values of the wave recorder in the coastal.