How does chaff interfere with radar detection?

In the context of military electronic countermeasures, chaff is an effective tool used to degrade the performance of hostile radar systems. It consists of an artificial cloud composed of a large number of tiny, metallic reflecting strips.1

When these strips are ejected into the air, they create strong radar echoes over a wide area. This interference functions in two primary ways:

• Masking: The dense cloud of reflections can hide the presence of real targets, such as aircraft, by overwhelming the radar receiver with clutter.1
• Confusion: The strong echoes generated by the chaff can create false targets, confusing the radar system and making it difficult for operators or automated tracking systems to distinguish between the chaff and actual threats.1

By generating these intense, widespread reflections, chaff forces radar systems to contend with significant background noise, thereby reducing their ability to reliably detect and track intended targets.1