The report gives an overview of emerging radar technologies within the area of detection of airborne targets. The subject is of considerable importance for the future Swedish capability to operate in Northern Europe and to successfully protect its territory. By identifying key areas where further research is needed for optimal use of the technological advances, the report aims to provide a direction for future research programs. Our study concludes that multifunctional radar sensors based on AESA technology will dominate the future air surveillance system, but that complementary sensor solutions like passive radar systems operating at lower frequencies can provide an important contribution to the overall performance. By designing an overall system consisting of several different kinds of subsystems, operating at varying frequencies and in different modes, the overall system flexibility is improved and the overall vulnerability is reduced. The advantages, however, lead to a higher overall cost for the complete air surveillance system. However, optimal realization of these goals requires further work in the areas of signal processing (target classification, waveforms, etc.) for radar stations and multifunctional for passive systems operating at several frequencies. The networked operation of the radar stations is also of great importance, regardless of manufacturer, especially with respect to questions like allocation of radar resources under varying operational conditions. Finally, broad knowledge of the possible solutions is important for good procurement, lowest total cost-of-ownership, and to avoid vendor lock-in.