This paper presents a pair-wise comparative strategy for supporting interpretation of dual-frequency and multi-polarimetry SAR images (i.e., Pi-SAR images). The basic requirement of Pi-SAR image-interpretation is to clarify the differences with respect to multi-polarized and multi-band information. Color composite images of Pi-SAR data are generally used for image interpretation. There is, however, no theoretical ground on combination cases for assigning multi-polarized Pi-SAR images to "Red (R)" "Green (G), " and "Blue (B)" planes, respectively. As a measure, we have introduced the pair-wise comparative strategy for Pi-SAR image-interpretation, which consists of following steps : Stepl) The dissimilarity measures between pair-wise comparative cases of Pi-SAR images (i.e., LHH, LHV, LVV, XHH, XHV, XVV) are calculated ; Step2) Through the quantification method type-IV, the scatter-diagrams are delineated with respect to items corresponding to each Pi-SAR image and ; Step3) As a final product, the composite images are produced by assigning the dissimilarity images to the color-planes of red, green and blue, respectively. Through the experiments, we conclude that the proposed composite images jointly with the pair-wise comparative table enable effective cross-interpretation for multi-polarized Pi-SAR images in stead of typical color composite images.
A multi-purpose field radiometer, MSR7000(Optical Research Corporation, Tokyo), was modified to be able to measure radiance and degree of polarization of the skylight either on the ground or on a ship (1nm interval, 5nm half width, IFOV=±1°, 415-1, 000nm). It is called MSR-M, which is Hyper Spectral Polarimeter. Measurements of maximum polarization, Pmax, are carried out to the direction of 90° from the sun in the principal plane, which is a plane determined by Sun, zenith and observation directions. The field data were taken at various sites such as the University of Alabama in Huntsville, off the coast and deserts in Nevada and California. Note that the deserts Nevada and Huntsville, Alabama, were under cloud free-conditions. The main results are; (1) semi-transparent cloud appears to decrease Pmax values irrespective of wavelengths; (2) the soil of Railroad Valley, Nevada, indicate little polarization, but its reflectance increases monotonously with wavelengths-(Eventually Pmax decreases with wavelengths)-(3) a sharp drop of Pmax is noted at around 700nm under lawn cover due to the sharp drop of polarization degree and sharp increase of reflectance. -(The polarimeter with 6 channels could not detect these characteristics. Note that reflectance of soil and lawn indicates smooth change with wavelengths); and (4) Optical characteristics of aerosols were not apparently derived in these observations.
The presence of propagated molecular gas around satellites is one of the most probable causes of optical degradations appeared on optical sensors equipped on the satellites. In order to evaluate transmittance degradation with various kinds of gases under different temperature and vacuum conditions, we built up the measurement systems. The main purpose of our study is to evaluate the variation of transmittance due to gas adsorption by making a specific, single component gas of high purity adhere to a glass material. As a result, the gases which are largely responsible for transmittance changes in the visible and near-infrared region can be identified. In our system, an optical glass, the site of adsorption, is set inside a cryostat and then a certain amount of molecular gas is injected. The amount of injected gas adsorption onto the optical surface is controlled by adjusting the sample surface temperature (150 K≤423K). In order to the wide wavelength coverage of earth observing sensors, two kinds of measurement systems were manufactured. The one for the UV to SWIR observation covers the wavelength from 350 nm to 2.5μm. The measurement accuracy of the UV-VISUAL-SWIR system is about 0.2%. The other for infrared observation covers from 2μm to 20μm. The measurement accuracy of the infrared system is about 1.6%. It turned out that our measurement systems have enough accuracies for evaluating the influence of gas contamination quantitatively.
Interferometric Synthetic Aperture Radar (InSAR) is an effective tool to detect and measure the amount of surface deformation caused by earthquake, volcanic activity, landslide, land subsidence and others. In this paper, the authors propose the methods of phase filtering and atmospheric correction for the measurement of local deformation. Next, we apply InSAR technique using JERS-1/SAR data to Zonguldak coalfield in Republic of Turkey and verify the accuracy of measurement using GPS data and existing documents. The Zonguldak coalfield is developing in the seaboard of the Black Sea where is approximately 240 km away eastward from Istanbul. This underground coal mine produces three million tons in each year since it has opened in 1848. Recently topographic deformations are remarkable to affect roads, houses and others infrastructures. Because the whole damage has not been grasped, we tried to measure the amount of surface deformation by InSAR (May-September, 1995: 132 days). As a result, small areas with high phase gradient are detected over the mining tunnels, and the maximum topographic deformation was approximately 200mm in slant-range direction for 4.5 months. In addition, the result of measurement by InSAR accorded with that by GPS measurement within 8mm.