Ww. Bonifant et al., Interferometric height estimation of the seafloor via synthetic aperture sonar in the presence of motion errors, IEE P-RAD S, 147(6), 2000, pp. 322-330
An end-to-end simulated processing chain related to an existing synthetic a
perture sonar (SAS) system is developed and described, including motion com
pensation, efficient image formation and autofocus procedures. The processi
ng is extended to include interferometric height estimation capability. It
is the goal of the paper to study the application of interferometry to SAS
systems in the presence of motion errors. The system is analysed with respe
ct to motion errors and the subsequent damaging effects to both imaging and
height estimation. Results using both measured and simulated data are pres
ented. The problem is addressed with respect to both one-pass and two-pass
imaging geometries, and it is hypothesised that for slowly varying target h
eight, one-pass SAS interferometry may be a more robust imaging tool than c
onventional SAS alone. The simulated results suggest that height informatio
n is recoverable even in some situations in which the conventional SAS refl
ectivity image is completely ruined by phase error induced blur. High-resol
ution SAS imaging coupled with interferometric height estimation for seaflo
or imaging has military applicability in mine detection or classification a
nd in topographic mapping in preparation for an amphibious assault. Civilia
n uses would include surveying of objects such as oil pipelines and seabed
mapping.