A model-based neural network is developed for spectrum estimation. Its
architecture and learning mechanism are founded on the Einsteinian in
terpretation of the spectrum as a probability distribution ofphotons.
By considering a spectrum as an ensemble of photons, we derive the neu
ral learning mechanism from the basic physical principle of entropy ma
ximization of a canonical ensemble. This neural network is applied to
characterizing a recently observed phenomenon known as equatorial iono
spheric clutter that significantly affects operations of over-the-hori
zon (OTH) radars and communication links using high frequency radiowav
es propagating through the ionosphere. We utilize a specific parameter
ization of the internal spectral model, which is derived from the phys
ical principles of the propagation of electromagnetic waves through a
turbulent ionosphere. A set of parameters characterizing equatorial io
nospheric clutter is estimated The developed technique may have a broa
d applicability in scientific data analysis. (C) 1997 Elsevier Science
Ltd. All rights reserved.