Pulse Doppler Radar Range Calculator
Coherent radar signal processing: Analyze the PRF compromise between maximum unambiguous range (R_ua), Doppler blind speed (v_blind), and average transmitter power.
Pulse Parameters & Waveform
Ambiguity Boundaries & Power
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
What is the fundamental Pulse Doppler radar dilemma?
The radar ambiguity equation dictates that R_ua * v_blind = c * lambda / 4. Because the speed of light c is constant, choosing a low PRF to see distant targets unambiguously (large R_ua) forces the first blind speed v_blind to be very low, creating severe velocity ambiguities. Conversely, choosing a high PRF to measure supersonic aircraft velocity unambiguously shrinks R_ua to just a few kilometers, wrapping distant echoes across multiple pulse intervals.
What is a Doppler blind speed in Moving Target Indication (MTI)?
When an approaching or receding target travels a distance equal to an integer multiple of half the radar wavelength (k * lambda / 2) between successive pulses, the round-trip phase change between pulses is exactly 2π (360°). The digital MTI filter cannot distinguish this moving target from static stationary ground clutter (trees, mountains), making the target completely invisible (blind speed).
How do modern AESA radars overcome the range-Doppler dilemma?
Modern Active Electronically Scanned Array (AESA) fire-control radars employ Medium PRF sets with multiple staggered, non-harmonic pulse repetition intervals (e.g. 8 different PRFs per dwell). Chinese Remainder Theorem algorithms compare the folded aliased ranges and Doppler shifts across the multiple PRFs to mathematically untangle true range and true velocity simultaneously.