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Umaha, et al.

                regularizer  and stabilizer  during the training process,   preparing the data for CNN. The procedural steps for
                allowing for a faster and more stable rate of learning   the development and implementation of the proposed
                while reducing dependence on weight initialization. In   SpillNet model are presented in Figure 1. These steps
                addition, the RCs ensure effective training of the deep   are divided into three major phases: (i) data collection
                networks by providing shortcut paths for gradient flow.   (which is further  divided  into  the  pre-processing
                This  prevents  gradients  from becoming  too  small  as   and data storage phases), (ii) model development
                they propagate back through the network. The special   and implementation  (which includes algorithm
                feature  of  the  modified  CNN  model,  “SpillNet,”  is   modification and training, along with the selection of
                its  ability  to  analyze  SAR images  and automatically   training resources), and (iii) the output and performance
                identify and classify oil spills and look-alikes. It is   evaluation  phase. In the model development  and
                sensitive  to  important  surface  characteristics  of  the   implementation phase, the images were loaded into the
                ground or water, such as texture, color differences, and   deep  learning  environment,  and multiple  convolution
                patterns, allowing it to accurately locate oil spills and   layers  were  applied  with  filters  to  extract  important
                distinguish them from other look-alikes. This reduces   features from the images. BN was first applied to ensure
                the likelihood of false positives and demonstrates the   a good distribution of the dataset, followed by the use of
                model’s robust predictive and classification capabilities.  the Rectified Linear Unit (ReLU) activation functions
                                                                    to introduce  non-linearity  and detect  initial  features.
                3. Methodology                                      Pooling layers were also applied to downsample feature
                                                                    maps, which were then flattened into a one-dimensional
                This section describes the SAR image dataset used, as   array. Dense layers were used for classification, with the
                well as the data augmentation techniques employed to   model classifying the images into oil spill and non-oil
                enhance the dataset and the pre-processing steps for   spill  (including  the  look-alikes)  categories.  The  final


                                                           CNN for oil spill detection






                                                                       Model development and  Output and model
                                     Dataset collection
                                                                  Implementation            evaluation
                                              Data storage   Algorithm      Training           Trained
                                Preprocessing
                                               for use       modification   resources       SpillNet model
                                                             & training
                                   Localisation                Integration of  TensorFlow
                                   and cropping                 DSCL, BN,     Keras library
                                                                 and RC
                                                                                         Performance metrics:
                                    Rescaling                                Google Colab  Mean precision,
                                    or resizing                Fixing of input  Python 3.7  mean recall,
                                                               layers, conv1
                                                               residual blocks            accuracy, error rate,
                                                                                           mean IoU, mean
                                   Radiometric                                            pixel accuracy, and
                                    calibration                Downsamples,                mean specificity
                                                                upsamples,
                                                                and conv2
                                  Noise filtering
                                                                Training, data
                                  Conversion to                augmentation,
                                  real luminosity               loss function,
                                     values                   optimizer, learning
                                                               rate,  batch size,
                                                                 and epoch
                    Figure 1. Procedural steps for the development and implementation of the proposed SpillNet model
                Abbreviations: BN: Batch normalization; conv1: Initial convolution layer; conv2: Final convolution layer;
                CNN: Convolutional neural network; DSCL: Depthwise separable convolutional layers; IoU: Intersection
                over Union; RC: Residual connections.



                Volume 22 Issue 3 (2025)                        36                                 doi: 10.36922/ajwep.8282
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