DocumentCode :
2106401
Title :
Aliasing effects mitigation by optimised sampling grids and impact on image acquisition chains
Author :
Vitulli, R. ; Bello, U. Del ; Armbruster, P. ; Baronti, S. ; Santurti, L.
Author_Institution :
TOS/ETD, Vitrociset Netherlands c/o ESA ESTEC, Noordwijk, Netherlands
Volume :
2
fYear :
2002
fDate :
2002
Firstpage :
979
Abstract :
An insufficient sampling rate can cause the introduction of unwanted effects in the samples of the image: the aliasing phenomenon. The aim of this paper is to investigate the possibility to mitigate the aliasing effects, trying to respect as much as possible the Shannon criteria for the image sampling. A model for the system modulation transfer function (MTF) of a hyperspectral push-broom sensor is developed. Quantitative quality indexes are adopted in order to assess the aliasing effects on the images. By using the MTF and the quality indexes, the relationship between aliasing and parameters of the optical system or of the electronic apparatus will be investigated. An alternative and more effective solution could be to try to respect as much as possible the Shannon criteria. Recent improvements in CCD technology make hexagonal sampling feasible for practical applications and bring a new interest on this topic. In our work, the advantages of hexagonal sampling with respect to conventional rectangular sampling are analysed under general assumptions. Nevertheless, using a hexagonal detector has an impact on the detection and imaging chain. In particular, processing steps must take into account the improved sampling geometry. This leads to adaptation of existing algorithms and even new processing architectures.
Keywords :
CCD image sensors; geophysical equipment; geophysical signal processing; geophysical techniques; image processing; image sampling; remote sensing; terrain mapping; CCD image sensor; Shannon criteria; algorithm; aliasing effect; equipment; geophysical measurement technique; hexagonal detector; hexagonal sampling; hyperspectral remote sensing; image acquisition chain; image processing; image sampling; instrument; land surface; mitigation; model; modulation transfer function; optimised sampling grid; push-broom sensor; quantitative quality index; rectangular sampling; remote sensing; sampling geometry; sampling rate; terrain mapping; Charge coupled devices; Hyperspectral imaging; Hyperspectral sensors; Image sampling; Optical modulation; Optical sensors; Sampling methods; Sensor phenomena and characterization; Sensor systems; Transfer functions;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Geoscience and Remote Sensing Symposium, 2002. IGARSS '02. 2002 IEEE International
Print_ISBN :
0-7803-7536-X
Type :
conf
DOI :
10.1109/IGARSS.2002.1025749
Filename :
1025749
Link To Document :
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