Low-probability-of-intercept radar

A low-probability-of-intercept radar (LPIR) is a radar employing measures to avoid detection by passive radar detection equipment (such as a radar warning receiver (RWR), or electronic support receiver) while it is searching for a target or engaged in target tracking. This characteristic is desirable in a radar because it allows finding and tracking an opponent without alerting them to the radar's presence. This also protects the radar installation from anti-radiation missiles (ARMs).

LPI measures include:

• Power management and high duty cycle, meaning the transmitter is on most of the time (long integration times)
• Wide bandwidth (or Ultra-wideband)
• Frequency agility, and frequency selection
• Advanced/irregular scan patterns
• Coded pulses (coherent detection)
• High processing gain
• Low sidelobe antennas