A Comparison of Data Augmentation Techniques in Training Deep Neural Networks for Satellite Image Classification.

Satellite imagery allows a plethora of applications ranging from weather forecasting to land surveying. The rapid development of computer vision systems could open new horizons to the utilization of satellite data due to the abundance of large volumes of data. However, current state-of-the-art computer vision systems mainly cater to applications that mainly involve natural images. While useful, those images exhibit a different distribution from satellite images in addition to having more spectral channels. This allows the use of pretrained deep learning models only in a subset of spectral channels that are equivalent to natural images thus discarding valuable information from other spectral channels. This calls for research effort to optimize deep learning models for satellite imagery to enable the assessment of their utility in the domain of remote sensing. This study focuses on the topic of image augmentation in training of deep neural network classifiers. I tested different techniques for image augmentation to train a standard deep neural network on satellite images from EuroSAT. Results show that while some image augmentation techniques commonly used in natural image training can readily be transferred to satellite images, some others could actually lead to a decrease in performance. Additionally, some novel image augmentation techniques that take into account the nature of satellite images could be useful to incorporate in training.