Improving the Classification Accuracy of Fragmented Cropland by using an Advanced Classification Algorithm

<p>Fragmented crop land and marginal landholdings play an important role to classify the landuse and adopt different cropping and management practices. Here the implementation crop classification algorithms are very much difficult and produce results with lower accuracy. Static imagery captured in the optical bands are often contaminated with cloud cover and fail to detect the phenological as well as the structural changes happening during the crop growth. This is very common and most typical in Indian climatic condition. Here, during monsoon period capturing temporal satellite images of the crop periods is a very challenging task. Therefore, the present study aims at application of a novel crop classification algorithm that utilizes the temporal patterns of synthetic aperture radar (SAR) datasets from Sentinel-1 in mapping of landuse of an agriculture system, that is fragmented, small and heterogeneous in nature. Here we used different polarization of Sentinel-1 datasets and developed the temporal crop patterns of different crops grown in semi-arid region of India. Further, an advanced classification algorithm such as time weighted dynamic time wrapping (TWDTW) is employed to classify the cropland with a higher accuracy. Pixel based image analysis was carried out and tested their applicability for cropland mapping. In-situ data sets are collected from the study site to validate the exhibited results from classification outputs. The overall accuracy of the pixel based TWDTW method performed very good results with accuracy of 63 %. The Kappa coefficient is found to be 0.58. The findings confirmed that the pixel based TWDTW algorithm has the potential to delineate the croplands, which were subjected to varying irrigation treatments and management practices, using sentinel-1 datasets.</p><p><strong>Keywords:</strong> crop classification, landuse, image analysis, Sentinel-1, TWDTW</p>

Comparative analysis of NOCT values for mono and multi C-Si PV modules in Indian climatic condition

The power output of Photo-voltaic modules is generally rated at STC (Standard Test Condition), 1000W/m2 irradiance, 25°C temperature and 1.5G Air Mass. But in actual field condition the situation is different from STC. Output of PV module is a function of Irradiance, ambient temperature, wind speed and module temperature. It is well established that power output of PV module decreases with increase of module temperature. So it is important to know the temperature of PV module to determine the reduction in power output due to temperature. Module temperature can be determined if irradiance at that instant and NOCT value of that module is known. This work presents the variation in NOCT value with respect to rated power output of PV module and comparison of NOCT values for same rated power mono and multi crystalline Si modules from various manufacturers. According to this study NOCT value increases with the wattage of PV module. For same rated power modules, NOCT value of mono crystalline Si is more than multi crystalline Si.