Apodization Functions for 2D Hexagonally Sampled Synthetic Aperture Imaging Radiometers. - Université Pierre et Marie Curie Accéder directement au contenu
Article Dans Une Revue IEEE Transactions on Geoscience and Remote Sensing Année : 2002

Apodization Functions for 2D Hexagonally Sampled Synthetic Aperture Imaging Radiometers.

Résumé

It is now well established that Synthetic Aperture Imaging Radiometers (SAIR) promise to be powerful sensors for high-resolution observations of the Earth at low microwave frequencies. Within this context, the European Space Agency (ESA) is currently developing the SMOS mission. The Y-shaped array selected for SMOS is fitted with equally spaced antennae and leads to a natural hexagonal sampling of the Fourier plane. This article deals with the choice of the apodization function to be applied to the complex visibilities. The aim of this function is to reduce the Gibbs phenomenon produced by the finite extent of the star-shaped frequency coverage and the resulting sharp frequency cut-off. A large number of windows are introduced. A comparison of these in terms of their spatial domain properties is given, according to criteria relevant for remote sensing of the Earth surface. This paper also describes how discrete Fourier transform calculations over hexagonal grids can be performed using a simple algorithm. Actually, standard FFT algorithms designed for Cartesian grids and which have a long track record of optimization can be re-used. Finally, an interpolation formula is given for resampling data from hexagonal grids without introducing any aliasing artifacts in the resampled data.
Fichier non déposé

Dates et versions

hal-00005158 , version 1 (06-06-2005)

Identifiants

Citer

Eric Anterrieu, Philippe Waldteufel, André Lannes. Apodization Functions for 2D Hexagonally Sampled Synthetic Aperture Imaging Radiometers.. IEEE Transactions on Geoscience and Remote Sensing, 2002, 40(12), pp.2531-2542. ⟨10.1109/TGRS.2002.1176146⟩. ⟨hal-00005158⟩
98 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More