  The problem of detecting buried unexploded ordnance (UXO) is addressed with a
sensor deployed from a shallow-draft surface vessel. This sonar system produces
three dimensional synthetic aperture sonar (SAS) imagery of both surficial and
buried UXO across a range of environments. The sensor's hardware design was
based in part upon data created using a hybrid modeling approach that combined
results from separate environmental scattering and target scattering models.
This hybrid model produced synthetic sensor data where the
sensor/environment/target space could be modified to explore the expected
operating conditions. The simulated data were also used to adapt a set of
existing signal processing algorithms for formation of three-dimensional
acoustic imagery.
  Recently, the sonar system has been integrated to a test platform, and
experiments have been conducted at a trial site in the Foster Joseph Sayers
Reservoir near Howard, PA. This test site has been prepared with several buried
man-made objects. Initial results show that fully buried targets can be
detected.
