Yoshinari Oguro

Comparison of SAR and optical sensor data for monitoring of rice plant around Hiroshima

Abstract Through the research on the application of the multi-temporal data acquired with Landsat-5 TM, SPOT-2 HRV, SPOT-4 HRVIR and RADARSAT-1 SAR to monitoring of rice field following features are clarified. Vegetation indices NDVI (Normalized Difference Vegetation Index) and EVI (Extended Vegetation Index) derived from different optical sensors TM, HVR, HRVIR indicate nearly same characteristics suggesting validity of calibration of respective sensors. It was found that by combined use of multi-temporal vegetation indices NDVI and EVI together with SAR (Synthetic Aperture Radar) data it was found that rice planted area can be estimated with the error less than 2%.

Monitoring of a rice field using landsat-5 TM and landsat-7 ETM+ data

Abstract Through the research on the application of the multi temporal data acquired with Landsat-5 TM and Landsat-7 ETM+ to monitoring of rice field the following features are clarified Two vegetation indices NDVI (Normalized Difference Vegetation Index) and EVI (Extended Vegetation Index) obtained from Landsat-5 TM data of 7 July 2000 and that from Landsat-7 ETM+ data of 6 July 2000 show almost the same feature proving the validity of calibration of both sensors. NDVI computed from satellite data increases corresponding to the growth of rice plants until the flowering stage while EVI further continues to increase until the fructification stage. The vegetation indices computed from the in situ survey data with a portable multispectral radiometer do not coincide with those computed from satellite data. This is because that the reflectance of the background such as soil and water is included in the satellite data.

Application of ERS-2/SAR data for the 1999 Taiwan earthquake

Abstract The applicability of interferometric SAR (InSAR) for detection of urban damages and land displacements caused by The 1999 Great Taiwan earthquake (Chi-chi earthquake) occurred on Sep. 21, 1999 were studied based on the data acquired on ERS-2 repeated pass. Three ERS-2 SAR data acquired on Jan. 21, May 6, and Sep. 23 in 1999 were used, the former two were acquired before the earthquake occurrence and the third was acquired two days after the earthquake. Two major results are obtained from the study. The first is the verification on the effectiveness of coherence information for detecting the damaged urban areas by building collapse, and the other is the effectiveness of differential interferograms to extract land displacement patterns. The latter result also proves that the extracted land displacement pattern by InSAR is consistent in general with the result of GPS survey.

Monitoring of new plantation development in tropical rain forests using JERS-1 SAR data

Abstract The authors studied the applicability of multi temporal SAR data obtained from JERS-1 SAR for monitoring the change in tropical rain forest conditions due to plantation development. The test site was the southern part of Sumatra Island, Indonesia. A total of seven JERS-1 SAR and one ERS-2 SAR data from 1992 to 1997 were analyzed together with two optical data, MOS-1 MESSR in 1990 and SPOT HRV in 1997. The result of this study verified that the backscatter change in multi temporal JERS-1 SAR data can be used effectively to monitor the process of plantation development in the test site, which accompanies the burning of felled tree trunks after deforestation, one of the causes for forest fire and serious smoke.

Higher resolution images for visible and near infrared bands of LANDSAT-7 ETM+ by using panchromatic band

Abstract Landsat-7 ETM+ (Enhanced Thematic Mapper Plus) simultaneously acquires multispectral image data with three different spatial resolutions; 30 meters for Band 1–5 and 7 (visible, near infrared and short wave infrared bands), 60 meters for Band 6 (thermal band) and 15 meters for Band 8 (panchromatic band). The spectral range of Band 8 is 520–900 rum and those of Bands 2, 3, and 4 are 530–610, 630–690 and 780–900 run respectively. Multispectral Band 2, 3 and 4 data at a 15 meter spatial resolution were generated by fusing with the higher resolution Band 8 data. Four methods are tested i.e. HSI (Hue, Saturation, Intensity) transformation, Brovey transformation and two proposed methods which utilize the statistical features of the multispectral and panchromatic data. The result indicates that in HSI and Brovey transformations the fusion of Band 8 data has reduced the numerical values of the average and the standard deviations of the original data while the proposed methods have generated the data of almost same color tone with nearly same values of average and standard deviations of the original data.

A comparative study of coherence patterns in C-band and L-band interferometric SAR from tropical rain forest areas

Abstract In this paper the capability of coherence patterns obtained from interferometric SAR (InSAR) for tropical rain forest monitoring are evaluated by using C-band and L-band SAR. The test site is a southern part of Sumatra Island with 50 by 50 km coverage. Several repeat-pass data pairs by JERS and ERS and tandem pairs by ERS are used to compare the coherence patterns between L-band and C-band SAR. The coherence patterns are evaluated for the following three items; coincidence with deforested areas, capability for land cover classification, and spatial frequency component. The result indicates that the capability of coherence by JERS repeat-pass pairs is almost compatible to that of coherence by ERS tandem pairs, while the capability by ERS repeat-pass pairs is relatively very poor. The result strongly supports the usefulness of the repeat-pass L-band InSAR for the purpose of tropical rain forest monitoring.

Comparisons of Brightness Temperatures of Landsat-7/ETM

The brightness temperature (BT) of Taklimakan Desert retrieved from the data of Landsat-7/ETM

A Mixed Pixels Estimation Method for Landsat-7/ETM+ Images

In this paper, the estimation method of the mixed pixel for satellite images has been proposed. A mixed pixel consists of several categories and the aim of this study is to estimate the mixture ratios of the categories. The filter of neighborhood pixels had been proposed. In this paper, the optimal filter coefficients have been considered in detail.

A High Speed Mixel Estimation Method by Using the Genetic Algorithm

The mixel (mixed pixel) which includes the multiple categories is one of the error factor in the land cover classification. Also to solve the mixel problem it requires a lot of calculations. A high speed mixel estimation method by using the Genetic Algorithm (GA) is proposed in this paper. In the result of the simulation for the actual remotely sensed data it shows the computation time reduces approximately 75% than the conventional method. For the qantitative evaluation by the simulated mixel data and actual image data, moreover, it is found that the accuracies of the mixel analysis of the proposed method is slightly better than those in some cases.

Comparison of Atmospheric Phase Delay on ALOS PALSAR Interferogram and Cloud Distribution Pattern on Simultaneously Observed AVNIR-2 Images

Tropospheric artifact is a serious problem for detecting crustal deformation using differential synthetic aperture radar intereferometry (DInSAR) technique. Advanced Land Observing Satellite (ALOS) has capability for simultaneous observation between synthetic aperture radar, PALSAR and optical sensor, AVNIR-2. We compared ALOS PALSAR interferogram with simultaneously observed AVNIR-2 images. Nominal spatial resolution of AVNIR-2 is sufficient for valuation of PALSAR interferogram. Terra/Aqua MODIS images are compared with PALSAR interferogram and cloud top heights is estimated. Test site is Miyagi prefecture where one of the most active seismic zone in Japanese islands. AVNIR-2 images show the two types of clouds pattern that causes interferometric phase delay. The first is lee wave cloud which shows the presence of gravity waves. The second is thick cloud as cumulus which is formed by condensation of water vapor. An interferogram show combination of phase delays in a couple of data. Simultaneously observed AVNIR-2 image is possible to use for evaluation of PALSAR interferometric fringe patterns.