Research activities in VHF/UHF radar are interesting for several reasons. One main reason is that the comparably low frequencies enable some detection capability through foliage (ground targets) or, in particular in combination with bistatic measurement geometries, enable detection of air targets of stealth type. These issues, especially the latter, have been studied in the project "Concept studies Guidance Radar". The work is summarized in this report. In particular, the concept with a ground based distributed radar for air surveillance (AASR - associative aperture synthesis radar) has been studied. In this concept, multistatic geometries in combination with frequencies which are in near resonance with the targets, give a system with good capacity of detection, positioning and tracking of air targets, including stealth targets. On the other hand, the particular measurement geometry gives non-trivial signal processing problems; we have shown, within the project, how to solve the so-called association problem. The work is well in line with the international development. There is an increasing interest for bi- and multistatic sensor systems, one reason being that signal processing demands which were previously without reach, with the current processing power are surmountable. The work is also important considering Sweden´s upcoming need for a modernization of the air surveillance radars.