03 — Radar Fundamentals
Radar Fundamentals
My engineering apprenticeship at QinetiQ Aberporth included radar systems used to track aircraft and targets on a weapons test range.
Principles
Pulse transmission and echo reception
A pulsed radar transmits radio energy and receives a small fraction reflected by a target. Radio waves travel approximately 300 metres per microsecond. Because the signal travels to the target and back, each microsecond of echo delay corresponds to approximately 150 metres of range. Antenna direction provides bearing, while Doppler shift indicates radial velocity.
Transmitted energy spreads on the outward path, and the reflected energy spreads again on the return path. In the basic radar range equation, received power decreases with the fourth power of range: doubling the distance reduces received power by a factor of sixteen.
Tools
Radar Range Equation
Estimate maximum detection range from transmit power, antenna gain, frequency and target radar cross-section.
Open → 02Doppler Shift Calculator
Target speed into frequency shift, with an interactive angle diagram showing why geometry matters.
Open → 03PRF & Ambiguity Explorer
Unambiguous range, blind speeds, resolution and duty cycle — with a live pulse-train timing diagram.
Open → 04PPI Display Demo
A working scope: rotating sweep, phosphor afterglow, range rings, and targets you place yourself.
Open →