The spectral radiance factor of paddy fields in the 400-1, 050 nm spectral regions was evaluated as an application of remote sensing in yield estimation and in the monitoring of rice status.
For this evaluation, three principal components were read out by principal component analysis of spectral radiance factor. One of the principal components showed the reflection in near-infrared regions was useful in estimating greenish plant biomasses in paddy fields. The other two factors showed reflection in visible regions and in the blue region.
The differences in the fertilizing status of paddy fields appeared in the spectral radiance factor from the middle of July to the beginning of August.
It is possible that the estimation of the growing status and the biomass products of the paddy field can be determined by using remote sensing techniques.

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The author investigated the surface radiant temperature with types of land-use upon two thermal imageries which were obtained on Jan. 3 1975, with MSS boarded on aircrafts along the courses shown in Fig. 1 and the following Conclusions were obtained.
1) In all of the types of land-use (exposed ground, road, parking place, evergreen forest and vegetable) except of turf and water surface, surface radiant temperature in the central part of the metropolis is higher early in the morning, and lower in daytime, than in the suburbs. The range of these surface radiant temperature during about 5.5 hours (6: 00 -11: 30) expands with a distance from the central part of the metropolis to the suburbs.
2) In spite of the areal differentiation of the diurnal viriation of the surface radiant temperature, discriminant analysis on these data may suggest that above mentioned 7 types of land-use are clustered in to 3 groups, i.e., heavily artificially deformed group (exposed ground, road, parking place, vegetable and turf), slighly artificially deformed group (evergreen forest) and water surface group, and in heavily artificially deformed land-use group there is also regional differentiation of the diurnal variation of surface radiant temperature between central part of the area and its suburbs.
3) Above phenomenon seems to be a case of such climate in urban area as Heat-Island or Cool-Island, though the surface radiant temperature is not so high at 11: 30 in the central part of the area because of the lack of the industrial activities for the New Year holidays.
4) Diurnal variation of the surface radiant temperature of exposed ground may be controlled by the ground water level or soil moisture.
5) It is clarified that there are areal differentiations of the range of the surface radiant temperature of water surface depending on such water-uses as river, pool, pond and sewerage, and such situations as upstream and downstream of the river.

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