Jamming remote object

A system for jamming a remote target comprises one or more jamming signal transmitters 101a-c, which generate and transmit at least a first sub-jamming signal and a second sub-jamming signal such that (i) at the location of the target 105, the interfering effects of the first and second sub-jamming signals combine so as to interfere with one or more target signals of the target to cause jamming of the target , and (ii) outside a region of space centred on the target object, the interfering effects of at least one of the first and second sub-jamming signals are insufficient to cause jamming. One or more of the sub-jamming signals may be transmitted in the form of relatively narrow beams directed at the target, one or more of the sub-jamming signals may be transmitted in the form of an omni-directional or wide field transmission. The sub-jamming signals may be transmitted from different locations and/or the same location. An overall jamming signal resulting from the combination of sub-jamming signals may be divided into sub-jamming signals based on time, power, frequency and/or code. The target may be a unmanned aerial vehicle. The jamming signals may be GNSS signals corresponding to different satellites.