Sonar data processing after real time data generation and storage. Modern sonar systems allow the user to concentrate on the task at hand of gathering data by recording “raw” data which can be manipulated or “processed” later. Because ship time is expensive and operational crews must be fully attentive to proper data gathering, post processing is most effectively performed in the less time-budgeted environment of the on-shore laboratory. Post processing can include mosaic construction, slant range and speed correction, false colorization and hard copy print generation.