Transformation classes for non-stationary signals in information measurement systems. IV. Relationship between the covariance form and time-frequency transformation type

Time-frequency transformations (TFT) used in signal analysis can change their form and characteristics of two-dimensional representation of non-stationary signals at the given form of the so-called covariance that is the property of TFT form modification associated with time or frequency scaling of the signal under analysis. Extended interpretation of the covariance property manifests itself in modification of TFT representation analytical forms. The paper considers some elements of theoretical methods for obtaining various TFTs and the measure of their adaptation to the specificity of signal under analysis. The methods for constructing IMS non-stationary signal transformations have been generalized. The main TFT structures were represented earlier ("Nauchnoe priborostroenie", v. 12 (2, 3), 2002).