A new clutter metric named CTSSM(Clutter Metric based on Target Structure Similarity Measure) is developed for electro-optical clutter estimation.With the target structure feature space established,the background image vectors are projected into that space.By measuring the normalized length of the projections,a quantitative estimation of the structure similarity between the background and the target is obtained.CTSSMhas two advantages over those available.First,by emphasizing the spatial arrangement rather ...