Figure 15: Schematic diagram of signals in a frequency-time space. Sinusoids are “on” for all time and
have horizontal tracks, linear chirps are straight lines with non-zero slope, bursts are time-localized,
etc. These localizations in frequency-time suggest different detection approaches for different classes
of signal. This space can be tiled in many ways. Particular tilings can have special merit for particular
waveforms, e.g., if a candidate signal projects preferentially onto a small fraction of a particular
mathematical basis while the noise does not.