Terrengreferert posisjonering for undervannsfarkoster

This report deals with terrain referenced positioning of underwater vehicles, also known as terrain correlation. There is no fundamental difference from airborne platforms. The report treats search methods and gradient methods. The search methods Point Mass Filter and TERCOM are treated in detail and results are given. The principle behind gradient methods is described, and results from FFIBM are presented. A short description of possible terrain characterisation functions is given. The report concludes that the Point Mass Filter is the best method of those treated.