Barrage jamming

Electronic warfare technique This image shows the effect of four carcinotron-carrying aircraft on a typical 1950s early warning radar. The aircraft are located at the 4 and 6 o'clock positions, which are completely filled with noise. Barrage jamming is an electronic warfare technique that attempts to blind ("jam") radar systems by filling the display with noise, rendering the broadcaster's blip invisible on the display, and often those in the nearby area as well. "Barrage" refers to systems that send signals in many bands of frequencies compared to the bandwidth of any single radar. This allows the jammer to jam multiple radars at once, and reduces or eliminates the need for adjustments to respond to any single radar. Early radar systems typically operated on a single frequency, and could only change that frequency by changing internal electronics. Against these radars, it was possible to use conventional radio sets to send out signals on the same band, causing the radar display to be filled with noise whenever the antenna was pointed in the general direction of the jammer. However, given that each individual radar would be operating on different frequencies, this "spot jamming" te