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STS2319 Lakshman N. R. et al.



                        Measuring rice yield from space: The case of Thai

                                     Binh Province, Viet Nam
                                         1
                    Lakshman Nagraj Rao , Kaiyu Guan , Ngo The Hien , Zhan Li
                                                                               5
                                                      2,3
                                                                      4
                               1  Asian Development Bank, Manila, Philippines.
               2  Department of Natural Resources and Environmental Sciences, University of Illinois at
                                 Urbana Champaign, Urbana, IL 61801, USA.
                 3  National Center for Supercomputing Applications, University of Illinois at Urbana
                                    Champaign, Urbana, IL 61801, USA.
              4  Center for Informatics and Statistics, Ministry of Agriculture and Rural Development, Viet
                                                Nam.
                 5  School for the Environment, University of Massachusetts Boston, MA 02125, USA.

            Abstract
            Despite a growing interest in using satellite data to estimate paddy rice yield
            in Southeast Asia, significant cloud coverage has led to a scarcity of usable
            optical data for such analysis. In this paper, we study the feasibility of using
            surface  reflectance  fusion  data  which  integrates  Landsat  and  Moderate
            Resolution  Imaging  Spectroradiometer  (MODIS)  images  to  circumvent  the
            cloud cover problem and estimate yield in Thai Binh Province, Viet Nam during
            the  second  growing  season  of  2015.  Our  findings  indicate  that  although
            Landsat–MODIS  fusion  data  are  not  necessarily  beneficial  for  paddy  rice
            mapping when compared with only using Landsat data, fusion data allows us
            to estimate the peak value of various vegetation indices and derive the best
            empirical relationship between these indices and yield data from the field.

            Keywords
            Crop cutting; yield, fusion; paddy area; remote sensing


            1.  Introduction
                Traditionally, crop area and yield are estimated using administrative data
            or sample surveys (Asian Development Bank 2016). However, measurement
            related concerns persist in both cases as data collection officers, farmers, and
            others involved in the process may have the tendency to systematically over
            or underestimate production and area in their assigned areas (Dillon and Rao,
            2018). An alternative to using administrative data or conducting surveys is the
            application of satellite remote sensing techniques, which has been ongoing
            for  the  past  several  decades  with  some  progress  achieved  for  paddy  rice
            (Kuenzer and Knauer 2013; Mosleh, Hassan, and Chowdhury 2015).
                From a methodological perspective, substantial progress has been made
            on remote sensing techniques to identify rice areas. However, estimating rice
            yield in the remote sensing context is still at a very nascent stage. There are
            several challenges associated with satellite-based crop yield estimation. First,
            there is a lack of reliable ground-truth crop yield data for model calibration

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