The compoundK-distribution model for sea clutter previously described in the literature provides the foundation for a quantitative treatment of the spatial and temporal correlation characteristics of the envelope of clutter returns. In the paper the compoundK-distribution model is extended to cover the spatial characteristics of sea clutter. The relationship of these characteristics to the physical basis of the model is described, and methods for their simulation are discussed. The effects of different radar range resolutions are analysed theoretically and these results compared with observations on real data. Finally, quantitative techniques are derived for optimising radar range resolution to give the best target detection performance in different clutter conditions, and some practical examples are presented.