Evaluation of optical satellite remote sensing for rice paddy phenology in monsoon Asia using a continuous in situ dataset
Abstract:In monsoon Asia, optical satellite remote sensing for rice paddy phenology suffers from atmospheric contaminations mainly due to frequent cloud cover. We evaluated the quality of satellite remote sensing of paddy phenology: (1) through continuous in situ observations of a paddy field in Japan for 1.5 years, we investigated phenological signals in the reflectance spectrum of the paddy field; (2) we tested daily satellite data taken by Terra/Aqua MODIS (MOD09 and L1B products) with regard to the agreement with the in situ data and the influence of cloud contamination. As a result, the in situ spectral characteristics evidently indicated some phenological changes in the rice paddy field, such as irrigation start, padding, heading, harvest and ploughing. The Enhanced Vegetation Index (EVI) was the best vegetation index in terms of agreement with the in situ data. More than 65% of MODIS observations were contaminated with clouds in this region. However, the combined use of Terra and Aqua decreased the rate of cloud contamination of the daily data to 43%. In conclusion, the most robust dataset for monitoring rice paddy phenology in monsoon Asia would be daily EVI derived from a combination of Terra/MODIS and Aqua/MODIS.
Document Type: Research Article
Affiliations: 1: Graduate School of Life and Environment Sciences, University of Tsukuba, Tennodai, Tsukuba, Japan 2: Institute of Agricultural and Forest Engineering, University of Tsukuba, Tennodai, Tsukuba, Japan 3: National Institute for Agro-Environmental Sciences, 3-1-3, Kannondai, Tsukuba, Japan 4: National Institute of Advanced Industrial Science and Technology, 1-1-1, Umezono, Tsukuba, Japan
Publication date: January 1, 2009