Relationship between LAI and NDVI for IRS LISS and Landsat TM bands Original Research Article

Owing to a highly non-linear relationship between leaf area index and normalized difference vegetation index, polynomials of orders 1 to 4 were fitted to LAI and NDVI for wheat and onion crops using the data collected over their crop growth cycles. It was found that fourth or higher order curve fit better for wheat data whereas polynomials of the order 2 or higher fit the data well for onion. Using the coefficients of the polynomials, NDVI values were computed for LISS-I/II and correlated with actual NDVI values and results were significant at 99% confidence level.