Demonstration of synthetic aperture sonar or radar using shallow water waves in a ripple tank with small cylindrical targets

Abstract

In an ideal stripmap synthetic aperture radar SAR or synthetic aperture sonar SAS experiment, a collocated transmitter and receiver array, respectively, generate a linear frequency modulated LFM pulse chirp that (1) reflects off of point-like targets that are placed along a smooth surface in the x,y plane and (2) receives backscattered echoes off the targets. The array (located a height h from the surface) may be towed (SAS) or flown (SAR), or in some airborne acoustic applications placed on a vehicle or track. In the stop and hop approximation waves are transmitted and then echoes vs. times are received and recorded at a point location along the track. At discrete locations along the track a set of N echoes are recorded which are pulse compressed using a correlation process. Using a time correlation backprojection algorithm the echoes are used to predict an image of the targets, namely the two-dimension reflectance f(x,y). Using a ripple tank, point-like spherical pulses are generated at locations guided...