Title : A novel approach to detect shrimp ponds using SAR
Abstract:
Satellite-based Synthetic Aperture Radar (SAR) technology has the ability to monitor surface features, immune to most atmospheric conditions. This study focuses on its potential within aquaculture, to use the presence of aerators as indicators of shrimp ponds. Spatial resolution of freely available SAR data (Sentinel-1), operates at approximately 10 m resolution. This limitation becomes evident when considering the small-scale nature of individual aerators typically used in shrimp aquaculture ponds (3 to 5 m). This research focused to bridge the resolution gap by devising an innovative method that uses SAR backscattering to detect even the smallest features, less than the sensor resolution under any atmospheric condition. The approach centers on the collective backscatter generated by arrays of aerators, which yields distinctive patterns. These patterns, combined with the application of the Constant False Alarm Rate (CFAR) algorithm, enable precise detection of aerators within shrimp ponds. The objectives of this study are multifold. First, to overcome SAR's resolution limitations for identifying small-scale features over a water body. Second, we apply the CFAR algorithm, capitalizing on the unique backscatter patterns associated with aerators. A significant advancement introduced here is the incorporation of dynamic thresholding within the CFAR algorithm, where the window size adapts dynamically to local noise and clutter, enhancing adaptability and accuracy. The validation process involved testing over shrimp ponds, in the geographical area of Nellore (Andhra Pradesh, India). The results were promising, with an overall F1 score of 80%. This research addresses the technological advancements in aquaculture monitoring and underscores the importance of site selection and spatial planning in line with regional policies, emphasizing a holistic approach to sustainable shrimp resource habitats, management, and competitive market dynamics.
Keywords: satellite, aerators, SAR, shrimp farming, pond detection, aquaculture
