A Measuring Device for Studying Scaling of Emissivities from Sub-pixel to Pixel

According to our experiment, emissivity at pixel scale is not equal to the average value of each sub-pixel emissivities. There exist scaling rule between mixed and single emissivities, which has important significance to understand models and to improve precision for quantitative inversion of land surface temperature and fluxes. In order to search and validate the rules, an automatic field observed device for component emissivity of mixed ground objects is developed by us. The device can directly measure emissivities and their distribution for each ground object in 300 mmtimes400 mm area. It is convenient to deploy and measure. The device is suitable to study scaling effect from sub-pixel to pixel for any thermal infrared remote sensing data. So far we still do not find similar observation device like above mentioned. Observed results using the device show that the device is effective and convenient; measurement principle is correct; the emissivity data are credible. For tow-dimension objects, we obtained a good agreement between measurements and prediction. However for three-dimension objects, it is difficult to predict multi-reflection and scaling. The device shows you advantage for studying multi-reflection and scaling. More experiments will be carried out in the future.