04623nas a2200469 a 4500 20260817163003.0 230117s2022 th uu m rtm 0| a1eng d .b12396540 AIT Thesis no.WM-22-13 Waruth Pojsilapachai Application of UAVS to monitor paddy crop growth, chlorophyll, and nitrogen content for informed decision making in water and nutrient management Pathum Thani, Thailand : Asian Institute of Technology, 2022 63 leaves : ill. Thesis; no. WM-22-13 A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management Thesis (M. Eng.) - Asian Institute of Technology, 2022 Fine-resolution satellite images provide useful information in Precision Agriculture (PA). The poor quality of satellite images during lousy weather days limits their field or farm-scale application, while unmanned aerial vehicle (UAV) images have higher resolution than satellite images. It can be used in crop monitoring to optimize plantation management and assess the optimum planting density more accurately. Moreover, the UAVs can perform scheduled flights to survey vegetation areas with accurate and updated maps to detect and deduce the root causes of detected instances of stress in the areas of plant growth. However, the resolution of images for the most widely used satellite images, such as Sentinel-2 (10 m by 10 m), includes vegetation canopies with varying degrees of heterogeneity within single pixels. In particular, the structured nature of rice fields comprising predominantly bare soil and weeds poses challenges when estimating the rice-level biomass and vigor from the coarse-resolution satellite images that present signals averaged over rice canopies and non-canopies (e.g., soil). The main objective of this study is to monitor and analyze crop growth, chlorophyll content, and nitrogen content in the paddy crop and identify critical zones for irrigation management using UAV-based images for informed decision-making at plot scale farming in Thailand. This study examined the relationship between the normalized difference vegetation index (NDVI), the triangular greenness index (TGI), and the green normalized difference vegetation index (GNDVI) utilizing extremely high resolution images captured by a UAV equipped with a multi-spectral imaging filter. The aggregated 2-cm-scale NDVI, TGI, and GNDVI values were compared with Sentinel-2 (10-m) products collected from a rice plot in Nakhon Pathom Province, Thailand, within 16 weeks. Results showed that when upscaling the high-resolution NDVI, TGI, and GNDVI values (by aggregating multi-spectral input bands for NDVI, TGI, and GNDVI) to coarser resolutions in a highly structured paddy field, all VIs correlated in the middle stage of crop growth. Also, it was found that the VIs from the UAV were lower than those from the Sentinel-2, mainly because the UAV had a higher resolution. Drone aircraft Decision making Climatic changes Mekong River Basin Shanmugam, Mohana Sundaram, Chairperson Shrestha, Sangam, Examination Committee Ho Huu Loc, Examination Committee Sarawut Ninsawat, Examination Committee Ministry of Agriculture and Cooperatives, Scholarship Donor Asian Institute of Technology. Thesis; no. WM-22-13 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B18056 .b12396540 multi m 240617 0 230117 m a m 0 mnarc mnarc mnait mnait 40 67 20 Barcode : 30020220004918 CREATED : 2023-05-01 RECORD # : i13422492 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : - CREATED : 2023-05-01 RECORD # : i13422509 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050121064348 CREATED : 2024-04-30 RECORD # : i13496451 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050121064280 CREATED : 2024-04-30 RECORD # : i13496463 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 6931 6931 0 0 0 0 MAIN MAIN mnarc 2026-08-17 0 AIT Thesis no.WM-22-13 30020220004918 2026-08-17 16:30:03 1 2026-08-17 40 0 0 0 0 MAIN MAIN mnarc 2026-08-17 0 AIT Thesis no.WM-22-13 2026-08-17 16:30:03 2026-08-17 67 0 0 0 0 MAIN MAIN mnait 2026-08-17 50.00 0 AIT Thesis no.WM-22-13 30050121064348 2026-08-17 16:30:03 1 2026-08-17 20 0 0 0 0 MAIN MAIN mnait 2026-08-17 50.00 0 AIT Thesis no.WM-22-13 30050121064280 2026-08-17 16:30:03 2 2026-08-17 20