Marine Observation Satellite-1 (MOS-1) is the first Japan's earth observation satellite and will carry three different type sensors, i.e., Multispectral Electronic Self Scanning Radiometer (MESSR), Visible and Thermal Infrared Radiometer (VTIR), Microwave Scanning Radiometer (MSR) and Data Collection System Transponder (DCST) as the mission instruments. Radiometric accuracy of the sensors were assessed taking into account sea-surface condition, influences due to sun-glitter, atmospheric effects and so on. Consequently it was found that the followings are noticeable. (1) Maximum and minimum radiance values and S/N ratio of MESSR are nearly equal to those of Landsat MSS. (2) The maximum influence of sun-glitter on MESSR data under the condition of 7(m/s) of wind speed over the sea surface and 10 o'clock of Local Mean Time ; LMT of the satellite orbit is approximately 2(%) in termes of the equivalent reflectance of sun-glitter while that for 11 o'clock of LMT is about 7(%). (3) Influence of sun-glitter on VTIR band 1 data, under the condition of 7(m/s) of wind speed over the sea-surface and 11 o'clock of Local Mean Time; LMT of the satellite orbit (in worst case) is approximately 9(%) in terms of equivalent reflectance of sun-glitter. Meanwhile those of VTIR band 2, 3 and 4 are negligibly small. (4) Due to the influence of the lim-darkening, input radiance of VTIR in the observation with the maximum scanning angle is reduced by 38(%) comparing with that for nadir observation. (5) Influence of polarization change due to antenna rotation on brightness temperature of MSR antenna was approximately 2.8(%) in typical case. (6) The percentage ratio of the contribution of the radiation from land through side-lobe of MSR antenna is less than 12.3(%).
Microwave remote-sensing techniques are based on interactions of electromagnetic waves with earth surfaces at the microwave wavelength region. Information on earth surfaces are extracted from backscattered or thermally-emitted microwaves from earth surfaces. Scattering and emissive characteristics of terrain which characterize various terrain surfaces are called the microwave signature. This paper reviews the recent studies on microwave signatures for remote sensing. The paper discusses experimental methods to obtain scattering and emissive characteristics of terrain and gives present knowledges on the typical surfaces on the earth: soil, vegetation, geologic surfaces, sea ice, snow, and ocean surfaces. The paper also discusses the theoretical studies on microwave backscatters from random media.
Kokai-River, one of the tributary stream of Tone-River, flooded again due to extremely heavy rainfall by the typhoon No. 10 during 5 to 6 August 1986. The thematic mapper of Landsat-5 has just acquired very valuable data observing the damage condition immediately after the flood. This brief paper overviews the damage condition of the flood by multispectral and multitemporal analyses using TM data taken before and after the flood. The distribution of the submerged areas by river-water and rainwater are clearly discriminated using the multispectral classification procedure with two TM data before and afer the flood. The multitemporal analysis using two TM data afer the flood reveals clear difference of the damage condition between the paddy field submerged by river-water and that submerged by rainwater.
In order to clarify problems on making color composite images of TM data, two step examinations are made on the one scene data of WRS 111-36 (Setouchi) received by NASDA EOC on May 8, 1984. The first step is making suitable B/W positive and negative transparencies (P-1 and N-2) of seven bands as working master images. The second step is to investigate effects of band combinations and color arrangements of color composites based on visual observation and to select combinations and arrangements suitable to visual interpretation. In making suitable P-1 and N-2 (the first step), it is confirmed that the most important factor is selection of γ-correction curves (transfer functions) suitable to each band taking into account TM data histograms. In the second step, 210 kinds of all possible color composites, which are products of 35 band combinations (1 block) and six color arrangements to each band combination to make color composites taking three out of seven bands and using three primary colors, are made at first. To investigate effects of band combinations and color arrangements and to select suitable combinations and arrangements, it is confirmed that the sea and land area should be examined separately. In the sea area, one block of color composites of each color arrangement is classified into 10 groups based on color appearance. The best combination of bands is (1, 2, 6), the second is (2, 3, 6), and the third is (1, 3, 6). The arrangement of colors (G, B, R), which is assigned to the band combination (i, j, k), is the best, when i is shorter, j is middle, and k is longer spec-tral band. In the land area, each block of color composites is roughly divided into two groups, depending on inclusion of the thermal band (band 6), but in some color arrangements the division is not so clearly, because band 4 shows superficial similarity to band 6. Each block is further divided into 11-14 kinds of smaller groups based on color appearance. Due to the fact that three are many kinds of objects in the land area, it is not so easy to decide the best color arrangement. However if required to select one, the recommended color arrangement will be (B, G, R).
A Study of Kuroshio based on eddy kinematics is proposed in this paper. Three kinds of data are used; remotely sensed data by satellites, hydrographic data on the sea, and knowledge data handed down by fishermen. At the first step, some cyclonic eddies several tens miles in diameter are detected on NOAA images. They are born at some capes located on the Pacific coast of Japan, which move too rapidly to make clear them by the observation on the sea. To chase them, however, remotely sensed data have a weak point; strongly disturbed by the atmosphere. At the second step, "phase analysis method" is introduced. The study area is focussed on the Cape Shionomisaki and its sea environs. Space information of an eddy is obtained from a Landsat image. Time series information of its formation is obtained from hydrographic data of sea levels at the ports near the cape; Kushimoto and Uragami. To support the analysis, knowledge data of sea are used. By synthesizing them, the mechanism of the birth of eddies is made clear. At the third step, the study area is scaled up to the Kumano Sea and the Enshuu Sea, extending more than 100 miles. NOAA data, hydrograpic data and knowledge data are synthesized to analyze the kinematical characteristics of the eddies; their formation, self-propelled motion, exfoliation, flowing down, coupling and amalgamation to an large cyclonic cold water mass 100 miles in diameter. A mechanism of the Kuroshio Meandering is revealed, in that the eddies born at the capes causes the spin up of the cold water masses that bend the course of the Kuroshio offshore. As the results, a strategy of attack to the Kuroshio is proposed, that is sharply focussed on the kinematics of the cyclonic eddies produced at the capes.