The northern part of Oman is characterized by an arid climate with an average annual precipitation of less than 100 mm. Under such conditions it is very important to estimate the infiltration and evaporation properties from soil surface especially after rainfalls in terms of the effective use of land and water resources. Dry Index (DI) was developed to evaluate the surface soil moisture content from NOAA AVHRR imageries. The underlying premise of the NOAA AVHRR image analysis is that spectral reflectance in the visible and near infrared bands and the emittance in the thermal band depend on the surface soil moisture content. For the purpose of verifying the premise and evaluating the final image output, experiments were carried out in the laboratory using soil samples obtained from the study area and radiometers which have similar spectral regions corresponding to the NOAA AVHRR. Dry Index was applied to the NOAA image for the rainfall during April 24-May 4, 1981. The results of the NOAA image analysis for soil moisture are as follows : (1) Dry Index (DI) was effective for obtaining information on the surface soil moisture and the arid environment. (2) The time series analysis of DI revealed the rate of drying of surface which in turn shows the possibility of estimating the characteristics of the water holding capacity of surface soil. (3) The results, thus obtained, will be applicable for the developments of land and water resources in the arid regions.
Marine Observation Satellite-1 (MOS-1) was successfully launched from Tanegashima Space Center, NASDA by N-II launch vehicle on Feb. 19, 1987. Two years (design life of MOS-1) have passed since the launch and MOS-1 is normally operated. NASDA planned to conduct MOS-1 Verification Progran (MVP) in order to evaluate MOS-1 observation system from various points of view and has conducted the MVP in collaboration with domestic and foreign investigators since March, 1987. In this paper, outline of activity of MVP and verification results obtained during two years are presented.
It is important for research and development of advanced imaging sensors, as well as data analysis technology, to estimate the actual overall spatial resolution characteristics of such as MESSR optical imaging sensors system onboard MOS-1. In MOS-1 Verification Program (MVP) we have studied computational techniques for estimating spatial resolution characteristics of satellite-based the MESSR sensor systems. Two methods for estimating overall spatial resolution characterestics of image sensor system have been investigated; Frequency domain method (Fourier transform) and Spatial domain method (Spatial convolution). Several factors affecting in estimation accuracy of the spatial characteristics are investigated by using numerical simulations. This paper presents outline of two estimation methods of PSF/MTF of an image sensor system, including subpixel data generation processing by multiple contiguous scanline data with slightly different phase of the edge of step targets, an analysis and compensation processing for the degradation of sensor's spatial characteristics due to relative motion between platform (satellite) and ground scene. Some results are shown through the estimation experiments for the PSF/MTF characteristics of the MESSR using MOS-Y MESSR CCT data.
Performance of Visible and Thermal Infrared Radiometer (VTIR) on MOS-1 satellite on measuring radiation is verified by comparing the obser-ved brightness temperature with that of computed from aerological data. The result shows VTIR is measuring radiation reasonably. Conparing estimated sea surface temperatures (SSTs) retrieving from VTIR by using different multichannel algorithms, the method using the relation among the radiations emitted from sea surface and observed by VTIR gives better result, because of close approximation. Small contribution of water vapor absorption band to obtain SST was found. Estimated SST has rms temperature difference of 0.7°C.
As a joint research with National Space Development Agency of Japan (NASDA) for past several years, the authors had been involved in the development of a retrieval algorithm for water vapor and cloud liquid contents using the Microwave Scanning Radiometer (MSR) to be on board the MOS-1 and in the estimation of the MSR data obtained in the airborne MSR verification experiment conducted by NASDA in 1984 through 1985. The frequency used is 23.8 GHz and 31.4 GHz. In succession to the joint research, MOS-1 Verification Program has been conducted using the MSR data of the MOS-1 satellite launched in February 1987. The estimation of the land-radiation effect on antenna temperature through antenna sidelobes and of the accuracy of the water vapor content retrieved from the MSR data have been made. As for cloud liquid content, its in-situ data is not practically available for the comparison with.the MSR data and therefore water vapor content alone was discussed. First of all, for more than 200 km of offshore distance, the increase of antenna temperature due to land radiation was found to be correctable using a function of the offshore distance. Because in this offshore distance, the increased antenna temperature measured by the MSR are considered to be almost equal to the calculated increase. Seasonal variation of the land radiation can be neglected. Consequently, the data taken within 600 km of off-shore distance, which have been so far considered erroneous because of influence of land radiation, can be used as close as 200 km offshore. Next, considerable amount of equivalent bias errors in MSR antenna temperature were found at both frequencies when all the bias errors in the retrieval algorithm are treated as equivalent errors in the measured temperature. Possible causes of the equivalent bias errors are discussed. By correcting MSR antenna temperatures for the equivalent bias errors, the retrieved water vapor content was found to be close to the calculated values of radiosonde data at Chichijima, Minamidatojima and Hachi-jojima. After the correction, the root-mean-square accuracy of the MSR-derived water vapor content is 2.8 kg/m2 which corresponds to 8 percent of the averaged water vapor content. This rms deviation is found to be relatively reasonable comparing with the estimation of receiver noise, random cloud distribution and sea-surface roughness.
MOS-DCS, MOS-1 Data Collection System, pro-vides some opportunities to moniter the phenomena of the earth surface, by using the communication technology combined with the satellite in low polar orbit. The mission objectives of the MOS-DCS are classified into two, such as (1) the location determination of DCP (Data Collection Platfrom), making use of the doppler frequency measurement at ground station, and (2) the data communication through the satellite. Its servicing area is restricted within the circle of about 5000 km radius centered at the ground station, so the location accuracy depends not only on the errors cocerning the measurement of some engineering parameters, such as doppler frequency, synchronized time, and so on, but also where the DCP located. This paper discusses the location accuracy of the MOS-DCS, regarding the originated DCP location within its servicing area and some correction para-meters, also combining with some results of experi-ments and simulations.
The Chugoku-Shikoku Chapter of the Remote Sensing Society of Japan was established on May 21, 1988 for the further prevalence of remote sensing research and education in this region, with the cooperations of universities, research institutes, government offices and private enterprises. With this valuable opportunity, we have a plan to introduce our activity in remote sensing. With the improvment of spatial resolution due to the present sensor technological development, wider availability of the regional observation system as well as the global observation have become possible. In Chugoku and Shikoku area, applied researches of remote sensing on both the land area, including land use, forest and disaster survey, and the sea area including oceanic envirnomental sur-veys of the Seto Inland Sea and its coast are being carried out on the regional basis by the several institutes. In this paper, we are reporting the feature on case studies related to remote sensing in Chugoku and Shikoku area, as well as the inaugural address as one of the projects commemorating the first year of newly established chapter.
In 1986 the ICSU General Assembly in Berne, Switzerland decided to establish the International Geosphere and Biosphere Programme: A Study of Global Change (IGBP). The Special Committee appointed by ICSU executive board identified an initial list of the following 4 areas for significant IGBP research. 1) Terrestrial biosphere-atmoshpheric chemistry interaction, 2) Marine biosphere-atmosphere interaction, 3) Biospheric aspect of the hydrological cycle, 4) Effect of climate change on terrestrial ecosystem. In addition the special committee established a working group to assess anticipated research capabilities in the following 4 areas. 1) Global geosphere-biosphere modelling, 2) Data management and information systems, 3) Techniques for extracting envionmental data of the past, 4) Geosphere biosphere observatories. Realizing the significance of the programme the preparatory national committee was organized under chairmanship of Prof. Kondo in Science Council of Japan, counterpart of ICSU. The chairmanship was taken over by Prof. Ohshima and studious efforts have been made to define appropriate themes for Japan. Followings are the themes proposed by the committee in respective areas. 1) Terrestrial biospheric chemistry interaction: 4 themes including trace gase and aerosol generated by agricultural activities and biomass combustion, etc. 2) Influence of climatic change on land vegetation: 6 themes including climatic influence on carbon balance on the vegetation field, etc. 3) The cycle of substance in ocean and biomass production: 14 themes including substance cycle and biomass in the ocean, etc. 4) Simulation and modelling of substance cycle and climatic change: 5 themes including modelling of climatic change, etc. 5) Monitoring of envionmental change: 5 themes including monitoring of vegetation in the wide area based on satellite data, etc. 6) Extraction of environmental data of the past: 4 themes including extraction of climatic change in the past.