A research study was conducted for summer paddy area estimation in Needamangalam and Mannargudi blocks of Cauvery delta zone of Tamil Nadu using Sentinel-2A satellite data. Optical data reflects the biological features of objects and provides spectrum information about the surface. Sentinel-2A satellite data were obtained for the study area during summer seasonand processed using ENVI Software. The paddy area was derived from the processed data using ground truth points collected during the cropping period of the study area. The summer paddy cultivating area in the Needamangalam and Mannargudi blocks of the Cauvery delta zone was estimated as 8082 ha. Needamangalam and Mannargudi blocks are having 5766.25 and 2315.75 ha, respectively as summer paddy area Accuracy assessment of the classification was carried out using the confusion matrix for the collected ground truth points and the overall classification accuracy was 89.6 percent with a kappa scoreof 0.79.

Crop inventory through remote sensing provides timely and precise information compared to the conventional method of area estimation. Synthetic Aperture Radar (SAR) overcomes the problems due to cloud cover during the crop growth period. Paddy crops were distinguished based on SAR backscattering coefficient values. This study was carried out in the Cauvery delta region during samba season 2020-21. MAPscape-RICE is a fully automated software used to process the SAR data and extracted dB values were subjected to the Multi-Temporal feature extraction method for estimating paddy growing areas. Continuous monitoring for crop parameters and validation exercise was done to assess the accuracy of the classified paddy area. Among the four districts, Thanjavur recorded the highest area under paddy of about 122684 ha and followed by Thiruvarur, Mayiladuthurai and Nagapattinam with an area of 119379 ha, 57015 ha and 46250 ha, respectively. A total paddy area of 345328 ha was estimated in the four districts of the Cauvery delta region using VH polarization with an overall accuracy of 93.4 per cent and 0.87 kappa index.