Spectral Density Matrix Data Structure

[kkappler]

For Single Station and Remote Reference processing the SDM is not typically stored, but instead the TFs are generated directly from operations on the FC arrays. For multiple station processing, the convention is to first produce the SDM with robust estimates of channel cross power for each channel pair, and then derive the TF from this (see Vozoff 1991 for details).

Note that in EMTF these SDMs were stored per band, and not per harmonic.

Estimates of single station and remote reference Transfer Functions can be computed from the SDM by appropriate aritmetic operations. Thus, by inserting the SDM as an intermediate data structure between the FC and the TF, we would pave the way for multiple station processing.