  In recent times, deep artificial neural networks have achieved many successes
in pattern recognition. Part of this success can be attributed to the reliance
on big data to increase generalization. However, in the field of time series
recognition, many datasets are often very small. One method of addressing this
problem is through the use of data augmentation. In this paper, we survey data
augmentation techniques for time series and their application to time series
classification with neural networks. We propose a taxonomy and outline the four
families in time series data augmentation, including transformation-based
methods, pattern mixing, generative models, and decomposition methods.
Furthermore, we empirically evaluate 12 time series data augmentation methods
on 128 time series classification datasets with six different types of neural
networks. Through the results, we are able to analyze the characteristics,
advantages and disadvantages, and recommendations of each data augmentation
method. This survey aims to help in the selection of time series data
augmentation for neural network applications.
