Spatial modeling of SPAD values for different type of crops using LISS-IV satellite imagery

The aim of present study is to assess the feasibility of Linear Imaging Self Scanning (LISS-IV) sensor data for the spatial modeling of SPAD (Soil-Plant Analysis Development) values to monitor the spatial distribution of chlorophyll contents in the agricultural areas. Six crop fields and ten different GPS locations in each crop field were selected for the measurement of SPAD values. The DN (digital number) values of each pixel of LISS-IV satellite image were converted into their top of atmospheric (TOA) reflectance values. The measurement of SPAD values were carried out at the same time of satellite passes over the study area. Two band algorithms was developed using cubic polynomial regression analysis between spectral coefficients and SPAD values. The performance of the two band algorithm was evaluated by using statistical performance indices like %Bias, root mean squared error (RMSE) and Nash-Sutcliffe efficiency (NSE). The values of %Bias, RMSE and NSE were found -0.04, 3.99 and 0.95 respectively.