Development of Digital Camera Attached Thermo Radiometer for the Vegetation Monitoring

Abstract

Not only for the temperature measurement, to understand the causes of the measured temperature which is observed the same area by both of camera and thermoradiometer is developed. Presently, the commercial thermoradiometer tends to have the narrow FOV, however the environmental temperature measurement needs the wider FOV for the area averaging. So we develop the wide FOV thermoradiometer for the environmental use. The thermoradiometer has the sufficient accuracy, RMSE 0.2 [K], for use. In addition, a digital camera to take the same area image as the thermoradiometer measurement synchronous with temperature measurement is equipped. Vegetation Coverage Ratio (VCR) and Shadow Content (SC) which affect the temperature is defined from the digital camera image. We measured the vegetation by this equipment. The temperature and SC show the relationship of inverse correlation. Observation temperature is affected from leaf surface temperature in vegetation cover area. VCR was able to quantify the relationship to observation temperature. In conclusion, the more deep understanding of the environmental temperature can be possible to measure VCR and SC at same time as temperature measurement.