Canada and the Netherlands are buying SIRIUS infrared radar systems for 16 of their ships (12 Canadian, four Dutch.) Based on the same heat sensing technology that is used so widely in armored vehicles, aircraft (and even infantry equipment), SIRIUS provides the same coverage as radar (out to the horizon). Infrared radar can be crucial, especially in operations near the coast, because it is passive (does not broadcast a signal, like radar does). Thus a small warship can stealthily monitor what is going on around it. Also, unlike normal radar (which is based on broadcasting electronic signals, and then analyzing those that bounce back), infrared is better at picking up small boats (or at least heat given off by engines, electrical devices or people). This is important, in this age of suicide bombers in small speedboats. Infrared radar can also pick up low flying cruise missiles that might be too stealthy for normal radar to catch. The SIRIUS systems cost about $8 million per ship.