This study was aimed at developing the classification methodology for the planting condition of paddy fields utilizing two time-series data acquisitions of the high-resolution SAR images of TerraSAR-X satellite during the rice transplanting and growing periods. We investigated whether it was possible to conduct classification of the paddy fields for the earlier transplanting of rice, the usual transplanting of rice, the later transplanting of rice, the direct seeding and also for the soybean and wheat crops. The methodology performed the cluster analysis for the study area using two SAR images of the rice transplanting period and the rice growing period. At first, we created polygons for each agriculture field. The classification was conducted for the earlier transplanting of rice, usual transplanting of rice, later transplanting of rice, direct seeding of rice, and for the soybean and wheat crops by the ratio for pixels in each cluster inside a polygon. In the proposed classification methodology, we were able to extract the direct sowing the soybean and wheat crops in the study area. The transplanting of rice (earlier, usual and later periods), wheat and soybean were clearly classified by the developed classification methodology. In addition, we understood that each field was not misclassified if there was a difference of the transplanting of about 20 days between earlier transplanting of rice and later transplanting of rice.
Sharpness of the satellite composite image is degraded by the period composite process associated with clouds and sensor zenith angles. In order to evaluate the image quality degradation by the period composite process, the period composites of band 1 of the corrected reflectance (CREFL) were created for the period of 1, 5, 10, and 30 days and for the spatial resolution of 250 m with a minimum pixel value among observations. The Modulation Transfer Function (MTF) of each MODIS period composite image are calculated by the method of edge-spectra ratio, where the Hanning Window is applied to the spatial pattern before the Fourier transformation. As a result, i) the 30 days period composite image was determined by the 5 days period composite image, ii) it was found that the 5 days period composite image should be combined with the cloud-free images and without the spatially deteriorated images in the end of scan angles in order to minimize the deterioration of image quality.
We propose a method of reversible digital watermark for point cloud data which is measured by a laser scanner on an aircraft. The proposed method performs confidential communications by embedding a bit string to the height of point cloud data, and is added points equal to the number of the bits. We verify the processing time of the proposed method through experiments with point cloud data.