Intelligent radar signal recognition and classification

This chapter investigates a classification problem for timely and reliable identification of radar signal emitters by implementing and following a neural network based approach. A large data set of intercepted generic radar signals, containing records of their pulse train characteristics (such as operational frequencies, modulation types, pulse repetition intervals, scanning period, etc.), is used for this research. Due to the nature of the available signals, the data entries consist of a mixture of continuous, discrete and categorical data, with a considerable number of records containing missing values.
To solve the classification problem, two separate approaches are investigated, implemented, tested and validated on a number of case studies. In the first approach, a listwise deletion is used to clean the data of samples containing missing values and then feed-forward neural networks are employed for the classification task. In the second one, a multiple imputation model-based method for dealing with missing data (by producing confidence intervals for unbiased estimates without loss of statistical power, i.e., by using all the available samples) is investigated. Afterwards, a feedforward backpropagation neural networks are trained to solve the signal classification problem. Each of the approaches is tested and validated on a number of case studies and the results are evaluated and critically compared.