Experimental studies of spectral reflectance characteristics and photosynthetic activities of some kinds of tree leaves were carried out. As a result, 1) spectral reflectance characteristics of leaves around the red edge did not show a direct relationship to the photosynthetic activity, 2) “blue shift" of the red edge can be caused only by water deficit in plant leaves without changes of pigment contents, 3) the mechanism by which water deficit cause the “blue shift" of the red edge can be supposed as follows : a dry leaf scatters incident light more than normal leaf because of its plentiful air spaces inside. This scattering should occur mainly at the surface of the leaf, hence less light penetrates into the leaf and absorption bands of pigments become narrower because of decrease of “detour effect."
Various environmental problems observed in areas ranging from a small region to the whole area of the earth are closely related to land use changes resulting from the human activity. To prevent further environmental problems, it is necessary to determine quickly changes of land use, predict the effect of the change and plan countermeasures. Therefore, estimating the present state of the land use is very important for the management of the terrestrial environment. Land cover distribution measurement by an artificial satellite has proven to be an effective means of estimating land use changes. However, most images observed by an artificial satellite are composed of mixed pixels which include various categories in a pixel. In particular, considering mixed pixels is necessary for land cover analysis using low spatial resolution image. In this paper, two methods of the gradient method and the matched filter method using hyper-spectral data to estimate the land cover ratio of interest in a pixel are proposed. The gradient method estimates coverage of interest using the characteristic wavelength range such as the absorption in the observation wavelength range, and the matched filter method estimates coverage of interest with finding the maximum value of cross correlation between signal of observation and interest. The common features of proposed methods are to use hyper-spectral data and estimate the coverage from only the spectral radiance of a specific category. The effectiveness of proposed methods were also examined. As a result, it was shown that the two methods proposed are effective for estimating land cover ratio of interest in a pixel.
It is required to estimate the distribution of stand volume of Hiba (Thujopsis dolabrata S. et Z) in natural forest of Shimokita peninsula for sustainable wood supply in this region. For this purpose, it is necessary to find the index that corresponds to the basal area of Hiba. We applied the Pattern decomposition method, one of the methods for overcoming mixel problem, which decomposite TM data to Water (W), Soil (S), and Vegetation (V) patterns. This method reduces the topographical effect to remote sensing data. It is found that the relation between W pattern value and basal area is useful to estimate the stand volume. Then we produced the distribution map of Hiba stand volume. Using the distribution map, we analysed the relation between stand volume of Hiba and two geographical conditions, the inclination angle and the distance from roads. We assumed that the location where inclination angle is under 25 degrees and distance from road is 200 m is suitable for felling, and estimated avairable volume of Hiba. Finally, we found that less than 20% of the stand volume is available for wood supply.
Measurement of atmosphere and surface optical properties were undertaken using photo-polarimeter and sun-photometer. The atmospheric observations were performed over Railroad valley (38°32'N, 115°44'W), Nevada (USA), where the altitude is 1432 m and Ivanpah playa, California (35°32'N, 115°24'W), where the altitude is 794 m, in wavelengths from 400 nm to 1000 nm. Sun-photometer indicated atmospheric aerosols of small size. The skylight polarization decreases with increasing the elevation of the sun, whereas the surface reflectance parameter increases. A change of skylight polarization with solar elevation is smaller than that of simulated results. A combined use of these radiometers would provide a useful information on atmospheric aerosol characteristics.
A round robin test for GLI (Global Imager) instrument was conducted with the three transfer spectrometers, 400-800 [nm], 500-1000 [nm] and 1300-2500 [nm] of the wavelength coverages, respectively. Also influence due to water vapor content in the integrating sphere of interest, in particular, at around 1400 [nm] of water vapor absorption band is evaluated. Using MODTRAN 3.7, it is found that the influence is approximately 40[%] for the relative humidity of 50 [%]. The absolute calibration accuracy of the integrating sphere was verified through a comparison of the radiance from the integrating sphere and the measured radiance with the transfer spectrometers. It is found that the difference between both shows around 1.5[%] for vibible to near infrared bands while approximately 2.5[%] for shortwave infrared bands.
The Lake Inbanuma, northwest of the Chiba Pref., was selected as a suitable study site for water quality assessment through the spectral characteristics of water region. In this lake, long term and chronic pollution has been reported and focused, and discharging lake water down to two diversion channel for purification, therefore, has been periodically attempted by the open-and-shut of several plural sluice gates. Two lakes at there represent a complex situation for major optical constituents and emergent spectral signals for remote sensing and provide a good test of combined radiometric correction methods developed for evaluating oil spilled ocean, turbid inland akes and reservoirs. By repetitious lab. experiments and "synch. site-surveying" of lake water, we encountered the following significant range; red reflectance peak was appeared the portion between 0.625 and 0.675μm and was also diagnostically useful for assessing relative turbid level. Based upon those factors, original set of TM band data vas digitally rectificated by the Filament-Shaped Method (United States EPA working group owns all copyright) as a combined radiometric correction processing. As a result, the complicated flowing patterns resulted from the "open-and-shut" of two sluice gates were visualized by the time-series distribution imageries by TTM image processing. Furthermore this technique can be applied to other site with considering parameter.
ADEOS/POLDER (POLarization and Directionality of the Earth's Reflectance) provides the multi-angle data of radiance and polarization of solar radiation reflected by the earth atmosphere-surface system in the visible and near-infrared wavelengths. This paper describes a procedure to extract aerosol characteristics over the ocean on a global scale from POLDER data. Our algorithm is achieved in practice using a look-up table which is compiled based on multiple scattering simulations in an atmosphere-sea surface model. The obtained daily local- and/or monthly mean global- maps present the Angstrom exponent and the optical thickness of aerosols. From these aerosol maps, it can be seen that: 1) the specific feature of maritime aerosols is shown, 2) the continental aerosols are blown over the ocean, e.g. in the north-west Pacific Ocean in spring.
In this study, in order to carry out the vegetation evaluation, the conventional inverse problem methods weren't used from the remotely sensed image, but the vegetation environment model of forward direction processing with three-dimensional computer graphics (3D CG) was developed and is utilized for the complicated vegetation area. First, the measurement model of the vegetation region in the remotely sensed image was proposed, and the virtual space in vegetation area which placed the tree by 3D CG was made. Next, the vegetation region measurement model and the 3D CG virtual space in the vegetation area were linked, and measurement simulation for the remote sensing in the vegetation region was developed. Finally, the problem of vegetation evaluation by present remote sensing was examined as an analysis of developed measurement simulation.
A method of radiative transfer of the atmosphere-surface system in the visible and near infrared region of spectrum is outlined. In this chapter, doubling-adding method and Monte Carlo method are introduced.