Chirplet transform

[3] The first practical application of the chirplet transform was in water-human-computer interaction (WaterHCI) for marine safety, to assist vessels in navigating through ice-infested waters, using marine radar to detect growlers (small iceberg fragments too small to be visible on conventional radar, yet large enough to damage a vessel).

[4][5] Other applications of the chirplet transform in WaterHCI include the SWIM (Sequential Wave Imprinting Machine).

[6][7] More recently other practical applications have been developed, including image processing (e.g. where there is periodic structure imaged through projective geometry),[6][8] as well as to excise chirp-like interference in spread spectrum communications,[9] in EEG processing,[10] and Chirplet Time Domain Reflectometry.

Florian Bossmann, Jianwei Ma, Asymmetric chirplet transform—Part 2: phase, frequency, and chirp rate, Geophysics, 2016, 81 (6), V425-V439.

Florian Bossmann, Jianwei Ma, Asymmetric chirplet transform for sparse representation of seismic data, Geophysics, 2015, 80 (6), WD89-WD100.

Chirplet in a computer-mediated reality environment.
(a) In image processing, periodicity is often subject to projective geometry (i.e. chirping that arises from projection). (b) In this image, repeating structures like the alternating dark space inside the windows, and light space of the white concrete, chirp (increase in frequency) towards the right. (c) The chirplet transform is able to represent this modulated variation compactly.