This report gives a short account of the activities carried out in the Defence Force project "Radar Targets in Background" in the years 2004-2006. The report contains summarising conclusions and also gives an overview of obtained results, partial deliveries, etc. For more detailed information on the project activities, the reports and memos issued should be consulted. The project has been subdivided into two parts, the first of which is an international cooperation within CEPA where Sweden has been "leading nation", while the second is a national work. The main goal of the project is, and has been, to develop new and improved modelling methods, which can be used for calculating the radar cross section in several radar applications. Of specific interest has been the target-background interaction, i.e. the ambition has been to study the objects in their natural environment. Besides the development of modelling methods, an important part in this work has consisted of developing measuring and analysing methods which can support the modeling development through validating measurements. The work has resulted in a number of new calculation and analysis tools, measuring methods and insights. The international CEPA work has also given Sweden a broad contact network and an opinion of the capabilities of other countries and their ambitions within the field.