Abstract: The invention relates to an ASDE radar to supply information on airport surface traffic. A well-known ASDE radar comprises an antenna having an elevation-depending gain factor ##EQU1## for .omega..sub.1 .ltoreq..omega.<.omega..sub.2, where .omega..sub.1, .omega. and .omega..sub.2 represent angles of depression. In such a radar, the echo power of an airport surface target is independent of the distance, whereas the echo power of rain clutter is inversely proportional to the square of the distance. Consequently, a remote surface target still projected on the radar screen above the rain clutter, is likely to disappear in the rain clutter when approaching the radar; this may result in fatal consequences. To solve the above problem, the ASDE radar of the invention comprises a combination of an antenna having a gain factor ##EQU2## and a sensitivity time control circuit in its receiver.