The objective of this research program is to develop microwave scattering techniques for obtaining quantitative information about the characteristic dimensions of surface cracks in metals. Work carried out during the past year has emphasized experimental techniques. The use of an IF bridge and a nearfield dielectric probe to improve the sensitivity of our 100-GHz eddy-current measurement system is described. The results of measurements made on fatigue cracks in 2024-T3 aluminum using this improved system also are presented. The interpretation of these data to provide information about crack depth is explained in terms of a simple model. Finally, a theoretical approach for modeling the scattering from elliptically shaped cracks is outlined.