Evaluation of the Applicability of Rice Growth Monitoring on Seosan and Pyongyang Region using RADARSAT-2 SAR -By Comparing RapidEye-

Abstract

Radar remote sensing is appropriate for rice monitoring because the areas where this crop is cultivated are often cloudy and rainy. Especially, Synthetic Aperture Radar (SAR) can acquire remote sensing information with a high temporal resolution in tropical and subtropical regions due to its all-weather capability. This paper analyzes the relationships between backscattering coefficients of rice measured by RADARSAT-2 SAR and growth parameters during a rice growth period. And we applied the relationships to crop monitoring of paddy rice in North Korea. As a result, plant height and Leaf Area Index (LAI) increased until Day Of Year (DOY) 234 and then decreased, while fresh weight and dry weight increased until DOY 253. Correlation coefficients revealed that Horizontal transmit and Horizontal receive polarization (HH)-polarization backscattering coefficients were correlated highly with plant height (r=0.95), fresh weight (r=0.92), vegetation water content (r=0.91), LAI (r=0.90), and dry weight (r=0.89). Based on the observed relationships between backscattering coefficients and variables of cultivation, prediction equations were developed using the HH-polarization backscattering coefficients. Concerning the evaluation for the applicability of the LAI distribution from RADARSAT-2, the LAI statistic was evaluated in comparison with LAI distribution from RapidEye image. And LAI distributions in Pyongyang were presented to show spatial variability for unaccessible areas.

Estimation of Rice Cultivation Area by Threshold Method using Sentinel-1 Imagery in South Korea

“…(Hong et al, 2001), MODIS (MODerate resolution Imaging Spectroradiometer) 영상을 이용하여 지역별로 임계값을 다르게 적용하여 논 관개시기를 추정하고 관개 논 면적을 산 정하였다 (Jeong et al, 2012). 벼 생육에 따른 RADARSAT (C-밴드, 5.3 GHz, HH편광, S5/S6) 영상의 후방산란계 수의 범위는 -16 ~ -3 dB로, 담수 초기에 -16 ~ -13 dB, 최대생육기에 -4.4 ~ -3.1 dB로 나타났고 (Hong et al, 2000), 엽면적지수 등 생육인자와의 상관성이 높게 나타났다 (Na et al, 2014). 또한, 벼의 조생종과 중만생종의 생육단계별 후방산란계수의 차이를 이용하여 품종을 구분하는데 활용하였다 (Jang et al, 2012).…”

The Study of Applicability to Fixed-field Sensor for Normalized Difference Vegetation Index (NDVI) Monitoring in Cultivation Area

“…원격탐사는 전자기파를 감지하는 각종 기기 및 센서를 이용하여 지표면, 물, 대기 현상에 대해 비접촉·비 파괴적인 방법으로 필요한 정보를 얻어내는 과학 기술로서 작황 추정에 널리 활용되고 있는 센싱 기술의 하나이다 . 원격탐사를 활용한 작황 추정은 주로 식생의 활력도와 생육 정도를 나타내는 분광지수인 식생지 수 (Vegetation Index)를 이용하는데, 식생지수 수치와 변 화 경향은 초고, Biomass, LAI 등 생육인자의 변화 특성을 잘 반영하는 것으로 알려져 있다 (Cohen, 1991;Lyon et al, 1998;Na et al, 2014). Kang et al (2009Kang et al ( , 2010, Kim et al (2005Kim et al ( , 2006, Kim and Hong (2008) …”