A modified time-frequency method for testing wide-sense stationarity

Recently, a time-frequency approach for testing stationarity was proposed. However, this method inefficiently detects nonstationarities of the first-order. Here, we present two contributions that improve the test performance and allow the detection of first-order evolutions. The first one is to use an adequate distance measure. The second is a modification of the method in order to consider the spectral content from the signal itself when computing the distances.