Hilbert Spectroscopy uses

Hilbert transforms In mathematics and in signal processing, the Hilbert transform is a specific linear operator that takes a function, of a real variable and produces another function of a real variable . This linear operator is given by convolution with the func ...

to analyze broad spectrum signals from

gigahertz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one ...

terahertz Terahertz or THz may refer to: * Terahertz (unit), a unit of frequency, defined as one trillion (1012) cycles per second or 1012 hertz * Terahertz radiation, electromagnetic waves within the ITU-designated band of frequencies from 0.3 to 3 terahe ...

frequency radio. One suggested use is to quickly analyze liquids inside airport passenger luggage.

References

Spectroscopy Signal processing Security technology {{spectroscopy-stub