Controlled acoustic measurements were conducted to investigate subcritical detection of targets buried in sand having a rippled sediment-water interface. The measurements were performed in a freshwater test-pond with a 1.5-m layer of sand on the bottom. Bottom ripple was formed by scraping the sand with a machined rake. Broadband (10 to 50 kHz) transducers were placed onto an elevated rail that translated horizontally permitting data to be processed using synthetic aperture sonar (SAS) techniques. Targets included silicone oil-filled spheres and flat-endcapped, solid aluminum cylinders. Data were acquired for various ripple wavelengths, heights, and orientations. For each bottom configuration, the seabed roughness over the buried target was measured to verify the ripple parameters and to estimate the small-scale roughness spectrum. This information was used in models predicting backscatter signal levels from the target and bottom. Results for spherical targets have generally been good. However, when cylindrical targets were inspected, model agreement was variable for reasons not fully understood. Characteristics of the target return are found to depend sensitively on ripple height and wavelength, and bottom parameters. Results are discussed with an eye towards understanding previously unexplained field test detections of buried cylindrical targets. [Work supported by ONR and SERDP.]