Multi-frequency and multi-polarization radar measurements over paddy rice field and their relationship with ground parameters

This paper aims to investigate the relationship between microwave backscatter signatures of different bands and polarizations and paddy field parameters so as to accumulate data for accurate inversion of these parameters. In the entire rice-growing season we altogether carried out eight experiments in three paddy fields separately and got a great amount of data of four frequencies(L,S,C,X), and three polarizations(HH,VV,VH). A wide range of ground parameters, such as leaf area index (LAI), biomass (fresh weight), canopy height, stem density, roughness and so on, were measured periodically through the season. In this paper, analyses based on statistical correlation showed that the lower-frequency bands (L, S) VH and HH polarization were highly correlated with LAI, biomass and canopy height while VV polarization was poorly correlated. But the highest correlation coefficient with stem density was found in S band VV polarization. Polarization difference had high correlation coefficients on some unique conditions. Besides, we did some research on the matter that whether the paddy field was flooded.