Research Papers

Effects of changing rice cultural practices on C-band synthetic aperture radar backscatter using Envisat advanced synthetic aperture radar data in the Mekong River Delta

[+] Author Affiliations
Nguyen Lam-Dao

University of Southern Queensland, Faculty of Engineering and Surveying, Toowoomba, Queensland 4350 Australia

Thuy Le Toan

Centre d'Etudes Spatiales de la Biosphe`re, 18 Avenue Edouard Belin, Toulouse Cedex 9, 31401 France

Armando Apan

University of Southern Queensland, Faculty of Engineering and Surveying, Toowoomba, Queensland 4350 Australia

Alexandre Bouvet

Centre d'Etudes Spatiales de la Biosphe`re, 18 Avenue Edouard Belin, Toulouse Cedex 9, 31401 France

Frank Young

University of Southern Queensland, Faculty of Engineering and Surveying, Toowoomba, Queensland 4350 Australia

Trung Le-Van

HoChiMinh City Institute of Resources Geography, Department of Geomatics, Ho Chi Minh City, Vietnam

J. Appl. Remote Sens. 3(1), 033563 (November 12, 2009). doi:10.1117/1.3271046
History: Received April 9, 2009; Revised October 9, 2009; Accepted October 22, 2009; November 12, 2009; Online November 12, 2009
Text Size: A A A

Abstract

Changes in rice cultivation systems have been observed in the Mekong River Delta, Vietnam. Among the changes in cultural practices, the change from transplanting to direct sowing, the use of water-saving technology, and the use of high production method could have impacts on radar remote sensing methods previously developed for rice monitoring. Using Envisat (Environmental Satellite) ASAR (Advanced Synthetic Aperture Radar) data over the province of An Giang, this study showed that the radar backscattering behaviour is much different from that of the reported traditional rice. At the early stage of the season, direct sowing on fields with rough and wet soil surface provides very high backscatter values for HH (Horizontal transmit - Horizontal receive polarisation) and VV (Vertical transmit - Vertical receive polarisation) data, as a contrast compared to the very low backscatter of fields covered with water before emergence. The temporal increase of the backscatter is therefore not observed clearly over direct sowing fields. Hence, the use of the intensity temporal change as a rice classifier proposed previously may not apply. Due to the drainage that occurs during the season, HH, VV and HH/VV are not strongly related to biomass, in contrast with past results. However, HH/VV ratio could be used to derive the rice/non-rice classification algorithm for all conditions of rice fields in the test province. The mapping results using the HH/VV polarization ratio at a single date in the middle period of the rice season were assessed using statistical data at different districts in the province, where very high accuracy was found. The method can be applied to other regions, provided that the synthetic aperture radar data are acquired during the peak period of the rice season, and that few training fields provide adjusted threshold values used in the method.

© 2009 Society of Photo-Optical Instrumentation Engineers

Citation

Nguyen Lam-Dao ; Thuy Le Toan ; Armando Apan ; Alexandre Bouvet ; Frank Young, et al.
"Effects of changing rice cultural practices on C-band synthetic aperture radar backscatter using Envisat advanced synthetic aperture radar data in the Mekong River Delta", J. Appl. Remote Sens. 3(1), 033563 (November 12, 2009). ; http://dx.doi.org/10.1117/1.3271046


Figures

Tables

Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.