Swedish Defence Research Agency

About: Swedish Defence Research Agency is a government organization based out in Stockholm, Sweden. It is known for research contribution in the topics: Radar & Laser. The organization has 1413 authors who have published 2731 publications receiving 56083 citations. The organization is also known as: Totalförsvarets forskningsinstitut.

Switched array concepts for 3-D radar imaging

Abstract: A number of antenna array concepts are investigated for three-dimensional radar imaging The concepts are based on switched arrays and wide-band signals to generate a virtual array or co-array to span a sector volume in the wave vector space to get image resolution The proposed arrays can be used for short range imaging in penetrating radar applications This approach is quite general and it can also be used in other system concepts Virtual arrays have mostly been used in radio astronomy and ultrasonic imaging The related synthetic arrays with antenna motion have been more common in radar systems

Assessing camouflage using textural features

Abstract: Developments in the area of signature suppression make it progressively more difficult to recognize targets. The emphasis has been on the reduction of distinct features, like hot spots in the infrared band. Thus, in order to obtain a low false alarm rate, threat sensors have to utilize more information, i.e. spatial and spectral properties. The purpose of our work is to develop a general tool for camouflage assessment. The approach proposed in this paper is to apply texture descriptors to quantify the similarity between different parts of an image. In addition, other descriptors are used to distinguish man-made object characteristics. The selection of an appropriate set of features is discussed. The assumption is that an area containing observable targets has different statistics than other areas. Statistical properties along with detected target specific features have to be combined with methods used in data fusion. An experiment with a data set of 44 reference images has been carried out, using a recently developed computer program called Terrtex. High correlation with perception experiments was achieved using only one or two texture features. The importance of a careful selection of background area size is finally discussed.