Chaff functions effectively as a countermeasure by creating a cloud of metal strips designed to confuse radar systems. When chaff is deployed from an aircraft, it disperses into the atmosphere and reflects radar signals back to the radar source. This clutter can mislead radar operators into detecting the chaff instead of the aircraft, allowing the aircraft to evade detection or targeting.
The metal strips are typically made of materials such as aluminum or other conductive metals, which enhance their radar reflectivity. This technique is particularly useful against radar-guided missiles, as it increases the likelihood of the missile homing in on the chaff rather than on the aircraft itself.
In contrast, the other options involve different countermeasure techniques that do not describe the specific action of chaff. Generating heat is associated with flares, signal jammers work by disrupting communication systems, and smoke screens function to obscure visibility rather than deceive radar. Each of these methods has its own specific use, but they do not relate to how chaff operates as a radar-evading measure.