Abstract: A method for recognising a target in a sonar image, the method comprising: normalising a sonar image; using/defining multiple test objects; rotating each test object between multiple positions; using a projection of each test object in each position as a template, so that multiple templates are provided for each test object, each template corresponding to a different rotational position; applying the multiple templates for the multiple test objects to the normalised image; and creating at least one feature vector for the image for use in target recognition.