Monitoring cotton crop condition through synergy of optical and radar remote sensing

Abstract

Synergistic use of Optical and Microwave remotely sensed data for cotton condition based on biophysical traits, indices from ground measurements and satellite derived reflectance were assessed. Regression models derived for estimating LAI, biomass and VWC using ground based indices were applied to satellite products. LAI, biomass and VWC of cotton with optical VIs as input (R²= 0.42, 0.51 and 0.52) respectively were estimated. Correlation between RVI and plant height, crop age and VWC were found between 0.4 and 0.6. Fresh biomass from RVI ranged 100 –4000 gm⁻², dry biomass from NDVI ranged 50–950 gm⁻² and VWC 65–85%. Correlation between VIs and RVI was found to be non- significant. A multiple linear regression model using NDVI vs. LSWI and RVI were developed to assess LAI, biomass and VWC. The model predicted LAI with R² of 0.5 but failed to estimate biomass and VWC.

Keywords:

• SAR remote sensing
• VI
• RVI
• RISAT-1
• cotton biophysical parameters
• fresh and dry biomass
• Vegetation water content

Acknowledgement

The authors are thankful to Dr. Prakash Chauhan, Director, IIRS (ISRO), Tapan Misra, former Director, Space Applications Centre/ISRO for his constant encouragement and guidance during the study. This study was carried out as a part of the ARISE project funded by ISRO, authors are grateful for the same. Authors are also thankful to Shri D. Putrevu, Head MTDD AMHTDG/EPSA/SAC, Dr. Vyas Pandey, Professor, retired HOD, Department of Agrometeorology, AAU for their support in carrying out this program. We acknowledge MNCFC, New Delhi for the cotton crop mask.

Additional information

Funding

This work was supported by the ARISE project in ISRO.