Modeling Microwave Propagation in Natural Caves Passages

An approach for modeling the attenuation of radio signals at microwave frequencies in natural cave passages has been developed. The method involves sequentially modeling sections of uniform characteristics including straight segments, perhaps of differing cross-sectional shapes and sizes, curved segments, and sharp bends. Reasonably good correlation with experimental measurements has been demonstrated in a variety of cave passages although a few areas of discrepancy have been noted. The circumstances in which the theoretical results deviate from practice are discussed with a view to identifying the limitations of the technique for predicting performance.