Matches in SemOpenAlex for { <https://semopenalex.org/work/W765327201> ?p ?o ?g. }
Showing items 1 to 61 of
61
with 100 items per page.
- W765327201 abstract "This thesis presents the research made on signal and data processing for THz imaging, with emphasis in noise analysis and tomography in amplitude contrast using a THz time-domain spectrometry system. A THz computerized tomography system was built, tested and characterized. The system is controlled from a personal computer using a program developed ad hoc. Detail is given on the operating principles of the system?s numerous optical and THz components, the design of a computer-based fast lock-in amplifier, the proposal of a local apodization method for reducing spurious oscillations in a THz spectrum, and the use of a parabolic interpolation of integrated signals as a method for estimating THz pulse delay. It is shown that our system can achieve a signal-to-noise ratio of 60 dB in spectrometry tests and 47 dB in tomography tests.Styrofoam phantoms of different shapes and up to 50x60 mm is size are used for analysis. Tomographic images are reconstructed at different frequencies from 0.2 THz to 2.5 THz, showing that volume scattering and edge contrast increase with wavelength. Evidence is given that refractive losses and surface scattering are responsible of high edge contrast in THz tomography images reconstructed in amplitude contrast. A modified Rayleigh roughness factor is proposed to model surface transmission scattering. It is also shown that volume scattering can be modelled by the material?s attenuation coefficient. The use of 4 mm apertures as spatial filters is compared against full beam imaging, and the limitations of Raleigh range are also addressed. It was estimated that for some frequencies between 0.5 THz and 1 THz the Rayleigh range is enough for the tested phantoms. Results on the influence of attenuation and scattering at different THz frequencies can be applied to the development of THz CW imaging systems and as a point of departure for the development of more complex scattering models." @default.
- W765327201 created "2016-06-24" @default.
- W765327201 creator A5020348200 @default.
- W765327201 creator A5070117130 @default.
- W765327201 date "2014-07-02" @default.
- W765327201 modified "2023-09-24" @default.
- W765327201 title "Signal and data processing for THz imaging" @default.
- W765327201 hasPublicationYear "2014" @default.
- W765327201 type Work @default.
- W765327201 sameAs 765327201 @default.
- W765327201 citedByCount "0" @default.
- W765327201 crossrefType "dissertation" @default.
- W765327201 hasAuthorship W765327201A5020348200 @default.
- W765327201 hasAuthorship W765327201A5070117130 @default.
- W765327201 hasConcept C107816215 @default.
- W765327201 hasConcept C120665830 @default.
- W765327201 hasConcept C121332964 @default.
- W765327201 hasConcept C163716698 @default.
- W765327201 hasConcept C184652730 @default.
- W765327201 hasConcept C191486275 @default.
- W765327201 hasConcept C192562407 @default.
- W765327201 hasConcept C199360897 @default.
- W765327201 hasConcept C2779843651 @default.
- W765327201 hasConcept C41008148 @default.
- W765327201 hasConceptScore W765327201C107816215 @default.
- W765327201 hasConceptScore W765327201C120665830 @default.
- W765327201 hasConceptScore W765327201C121332964 @default.
- W765327201 hasConceptScore W765327201C163716698 @default.
- W765327201 hasConceptScore W765327201C184652730 @default.
- W765327201 hasConceptScore W765327201C191486275 @default.
- W765327201 hasConceptScore W765327201C192562407 @default.
- W765327201 hasConceptScore W765327201C199360897 @default.
- W765327201 hasConceptScore W765327201C2779843651 @default.
- W765327201 hasConceptScore W765327201C41008148 @default.
- W765327201 hasLocation W7653272011 @default.
- W765327201 hasOpenAccess W765327201 @default.
- W765327201 hasPrimaryLocation W7653272011 @default.
- W765327201 hasRelatedWork W1503523866 @default.
- W765327201 hasRelatedWork W1666287741 @default.
- W765327201 hasRelatedWork W1965878786 @default.
- W765327201 hasRelatedWork W2022721454 @default.
- W765327201 hasRelatedWork W2049857540 @default.
- W765327201 hasRelatedWork W2050706164 @default.
- W765327201 hasRelatedWork W2068164255 @default.
- W765327201 hasRelatedWork W2090215665 @default.
- W765327201 hasRelatedWork W2094946583 @default.
- W765327201 hasRelatedWork W2159268318 @default.
- W765327201 hasRelatedWork W2287794192 @default.
- W765327201 hasRelatedWork W2328976580 @default.
- W765327201 hasRelatedWork W2763942627 @default.
- W765327201 hasRelatedWork W2896702433 @default.
- W765327201 hasRelatedWork W2996251993 @default.
- W765327201 hasRelatedWork W3014838077 @default.
- W765327201 hasRelatedWork W3025269767 @default.
- W765327201 hasRelatedWork W412116098 @default.
- W765327201 hasRelatedWork W1904643246 @default.
- W765327201 hasRelatedWork W2024957828 @default.
- W765327201 isParatext "false" @default.
- W765327201 isRetracted "false" @default.
- W765327201 magId "765327201" @default.
- W765327201 workType "dissertation" @default.