In marine electronics, the "Big Four" (Furuno, Garmin, Raymarine and Simrad) offer CHIRP sonars, and they represent the most sophisticated sounding technology available to recreational and commercial fishermen. The name CHIRP comes from the phrase "compressed high-
intensity radar pulse." That pulse is more easily understood as a long, powerful sound signal that ranges in frequency from a very low 28 kHz to a high 250 kHz. A CHIRP system separates a return echo's frequencies to develop a very detailed, high-resolution image of targets only a few inches apart — in hundreds of feet of water.