气候变化领域集成服务门户(CCPortal): Full year crop monitoring and separability assessment with fully-polarimetric L-band UAVSAR: A case study in the Sacramento Valley, California

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DOI	10.1016/j.jag.2018.08.024
	Full year crop monitoring and separability assessment with fully-polarimetric L-band UAVSAR: A case study in the Sacramento Valley, California
	Li H.; Zhang C.; Zhang S.; Atkinson P.M.
发表日期	2019
ISSN	15698432
起始页码	45
结束页码	56
卷号	74
英文摘要	Spatial and temporal information on plant and soil conditions is needed urgently for monitoring of crop productivity. Remote sensing has been considered as an effective means for crop growth monitoring due to its timely updating and complete coverage. In this paper, we explored the potential of L-band fully-polarimetric Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) data for crop monitoring and classification. The study site was located in the Sacramento Valley, in California where the cropping system is relatively diverse. Full season polarimetric signatures, as well as scattering mechanisms, for several crops, including almond, walnut, alfalfa, winter wheat, corn, sunflower, and tomato, were analyzed with linear polarizations (HH, HV, and VV) and polarimetric decomposition (Cloude–Pottier and Freeman–Durden) parameters, respectively. The separability amongst crop types was assessed across a full calendar year based on both linear polarizations and decomposition parameters. The unique structure-related polarimetric signature of each crop was provided by multitemporal UAVSAR data with a fine temporal resolution. Permanent tree crops (almond and walnut) and alfalfa demonstrated stable radar backscattering values across the growing season, whereas winter wheat and summer crops (corn, sunflower, and tomato) presented drastically different patterns, with rapid increase from the emergence stage to the peak biomass stage, followed by a significant decrease during the senescence stage. In general, the polarimetric signature was heterogeneous during June and October, while homogeneous during March-to-May and July-to-August. The scattering mechanisms depend heavily upon crop type and phenological stage. The primary scattering mechanism for tree crops was volume scattering (>40%), while surface scattering (>40%) dominated for alfalfa and winter wheat, although double-bounce scattering (>30%) was notable for alfalfa during March-to-September. Surface scattering was also dominant (>40%) for summer crops across the growing season except for sunflower and tomato during June and corn during July-to-October when volume scattering (>40%) was the primary scattering mechanism. Crops were better discriminated with decomposition parameters than with linear polarizations, and the greatest separability occurred during the peak biomass stage (July-August). All crop types were completely separable from the others when simultaneously using UAVSAR data spanning the whole growing season. The results demonstrate the feasibility of L-band SAR for crop monitoring and classification, without the need for optical data, and should serve as a guideline for future research. © 2018 Elsevier B.V.
英文关键词	Classification; Crop growth monitoring; Full-polarimetric SAR; Multi-temporal image; Polarimetric decomposition; Scattering mechanisms
语种	英语
scopus关键词	assessment method; crop production; decomposition analysis; future prospect; image analysis; monitoring; scattering; spatiotemporal analysis; synthetic aperture radar; wheat; California; Sacramento Valley; United States; Helianthus; Juglans; Lycopersicon esculentum; Medicago sativa; Prunus dulcis; Triticum aestivum; Zea mays
来源期刊	International Journal of Applied Earth Observation and Geoinformation
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156545
作者单位	Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130012, China; Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom
推荐引用方式 GB/T 7714	Li H.,Zhang C.,Zhang S.,et al. Full year crop monitoring and separability assessment with fully-polarimetric L-band UAVSAR: A case study in the Sacramento Valley, California[J],2019,74.
APA	Li H.,Zhang C.,Zhang S.,&Atkinson P.M..(2019).Full year crop monitoring and separability assessment with fully-polarimetric L-band UAVSAR: A case study in the Sacramento Valley, California.International Journal of Applied Earth Observation and Geoinformation,74.
MLA	Li H.,et al."Full year crop monitoring and separability assessment with fully-polarimetric L-band UAVSAR: A case study in the Sacramento Valley, California".International Journal of Applied Earth Observation and Geoinformation 74(2019).