Thursday, 13 February 2003
Estimating underwater acoustical parameters from space-based synthetic aperture radar imagery
Synthetic aperture radar (SAR) imagery from satellites provides a range of data products that can reveal certain aspects of the underwater acoustical environment. Acoustical parameters of interest for naval applications are the spectrum of underwater ambient noise, the surface scattering coefficient and ocean structures such as internal waves and fronts that affect the horizontal propagation of sound. The SAR data products that can be linked to these acoustical parameters are surface wind fields, ship detections, gravity wave spectra and subjective identification of ocean features. We present examples from a series of ocean trials where SAR data has been used to estimate the underwater noise field and surface scatter coefficient. The high spatial resolution of existing SAR satellites and swath widths up to several hundred kilometres allows space-based SAR to contribute significantly to assessment of the underwater acoustical environment.