Automatic Spectral Rule-Based Preliminary Classification of Radiometrically Calibrated SPOT-4/-5/IRS, AVHRR/MSG, AATSR, IKONOS/QuickBird/OrbView/GeoEye, and DMC/SPOT-1/-2 Imagery-Part II: Classification Accuracy Assessment

To date, the automatic or semiautomatic transformation of huge amounts of multisource multiresolution spaceborne imagery into information still remains far below reasonable expectations. The original contribution of this paper to existing knowledge on the development of operational automatic remote sensing image understanding systems (RS-IUSs) is fourfold. First, existing RS-IUS architectures are critically revised. In this review section, the two-stage stratified hierarchical RS-IUS model, originally proposed by Shackelford and Davis, is identified as a subclass of the parent class of multiagent hybrid systems for RS image understanding, which is potentially superior to the two-stage segment-based RS-IUS architecture that is currently considered the state-of-the-art in commercial RS image-processing software toolboxes. Second, this paper highlights the degree of novelty of an operational automatic near-real-time well-posed model-driven application-independent per-pixel Landsat-like spectral-rulebased decision-tree classifier (LSRC) recently presented in RS literature. Third, five original downscaled implementations of the LSRC system are proposed to be input with a multispectral image whose spectral resolution overlaps with, but is inferior to, Landsat's. These five downscaled LSRC implementations are identified as the Satellite Pour l'Observation de la Terre-like SRC, the Advanced Very High Resolution Radiometer-like SRC, Manuscript received August 1, 2008; revised December 31, 2008 and July 1, 2009. First published December 4, 2009; current version published February 24, 2010. A. Baraldi was with the European Commission Joint Research Center (EC-JRC), 21020 Ispra, Italy. He is now with Baraldi Consultancy in Remote Sensing, 40129 Bologna, Italy (e-mail: andrea6311@gmail.com). L. Durieux was with the EC-JRC, 21020 Ispra, Italy. He is now with the Institut de Recherché Pour le Développement, Maison de la Teledetection, 34093 Monpellier Cedex 05, France (e-mail: Laurent.durieux@ird.fr). D. Simonetti is with the EC-JRC, 21020 Ispra, Italy (e-mail: dario.simonetti@ext.jrc.ec.europa.eu). G. Conchedda is with the European Commission, Brussels, Belgium (e-mail: giulia.conchedda@jrc.it). F. Holecz is with Sarmap s.a., 6989 Purasca, Switzerland (e-mail: fholecz@sarmap.ch). P. Blonda is with the Istituto di Studi sui Sistemi Intelligenti per l'Automazione, Consiglio Nazionale delle Ricerche, 70126 Bari, Italy (e-mail: blonda@ba.issia.cnr.it). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TGRS.2009.2032457 the Advanced Along-Track Scanning Radiometer-like SRC, the IKONOS-like SRC, and the Disaster Monitoring Constellationlike SRC, respectively. LSRC, together with its five downscaled implementations, called the integrated SRC system of systems, is eligible for use as the automatic pixel-based preliminary classification first stage of a two-stage stratified hierarchical RS-IUS instantiation. Fourth, to sustain the feasibility of the new downscaled LSRC implementations, a novel vegetation spectral index is introduced and discussed. In Part II of this paper, experimental results are presented and discussed for the entire SRC family of classifiers.