Foreword to the Special Issue on Hyperspectral Image and Signal Processing
T HE very high spectral resolution of remotely sensed hyperspectral data [1], rooted in technological, modeling and processing advances, has fostered a strong interest in this image modality at an unprecedented rate in recent years. In fact, the very high spectral resolution of hyperspectral data offers very significant potential in the identification of materials and their properties [2]. However, the high dimensionality of hyperspectral data (and its usually low spatial resolution) raises a series of new challenges on several fronts, namely, in signal and image processing, physical modeling, sensor design and calibration, applications and computationally efficient processing [3]. The aforementioned topics were addressed in the IEEE Geoscience and Remote Sensing Society (GRSS) Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS).1 After two successful editions in Grenoble, France (2009), and Reykjavik, Iceland (2010), the 2011 edition of WHISPERS took place in Lisbon. The venue was the Instituto Superior Técnico (IST), the largest and most reputed school of Engineering, Science and Technology and Architecture in Portugal. The general chairs of WHISPERS 2011 were Prof. José M. Bioucas-Dias from IST and Prof. Antonio Plaza from the University of Extremadura, Spain. The program chair was Prof. Jocelyn Chanussot from GIPSA-Lab, Grenoble Institute of Technology, France. After a careful review process, in which each submission received an average of 2.5 anonymous reviews, a total of 126 papers were accepted for presentation and publication in the proceedings of WHISPERS 2011. Of these, 92 were orally presented while the remaining 34 were presented as posters. In total, fourteen regular sessions (five on signal and image processing, three on physical modeling, two on sensor design, and five on applications) were organized, covering a wide spectrum of techniques and disciplines in this research area). Three special dedicated sessions were organized on advanced topics for hyperspectral data exploitation, including spectral unmixing, machine learning, and target detection. The technical program promoted the dissemination of research results and technical advances in the aforementioned topics and offered a fertile discussion forum for researchers coming from different areas and backgrounds. The technical program of WHISPERS 2011 also featured three plenary talks delivered by prestigious and highly recognized experts worldwide. Prof. Melba Crawford, from Purdue University, USA, delivered a talk entitled “Nonlinear manifolds for feature extraction: opportunities and challenges.” Dr. Alexander Held, from CSIRO Division of Marine and