Studies on canopy surface temperature for crop fields and forest measured IR thermometer
1993
Wang, X. (Hokkaido Univ., Sapporo (Japan). Faculty of Agriculture) | Horiguchi, I. | Machimura, T.
Infrared radiation (IR) emitted from the earth's surface is measured routinely from satellites. In order to utilize the infrared radiation, the characteristics of the surface temperature for crop fields and forest were studied by using an IR thermometer. The results show that the maximum surface temperature is higher than the maximum air temperature, and that the minimum surface temperature is lower than the minimum air temperature on fine clear days. Further, the maximum and minimum surface temperature were observed earlier than the maximum and minimum air temperatures. In the early growth stage of corn, the maximum surface temperature of the field is higher than those of soybean and cabbage fields. In the later growth stage, however,it is the lowest among these crop fields. In addition, the times of the maximum and minimum surface temperatures and the times of the maximum and minimum air temperatures of corn field are closer than those of soybean and cabbage fields. This seems to be related to the vegetation pattern particular to the corn field. The time of appearance of the maximum surface temperature coincided with the NOAA satellite overpassing. On the other hand, the time of the minimum surface temperature occurred 1 or 2 hours earlier than the NOAA overpassing. Therefore, the relationship between the surface temperature at 2 am, when the NOAA overpasses, and the minimum surface temperature were studied. Moreover, the relationship between the surface temperature at 9:30 am, when Landsat overpasses, and the mean surface temperature of the day or the maximum surface temperature were analyzed
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