What is the difference between a monostatic and a bistatic radar configuration?
Monostatic vs Bistatic
The bistatic radar equation: SNR = (P_t × G_t × G_r × λ² × σ_b) / ((4π)³ × k × T × B × F × R_t² × R_r²), where R_t = transmitter-to-target range, R_r = receiver-to-target range, and σ_b = bistatic RCS. The forward-scatter RCS (when the target is between TX and RX) can be very large: σ_forward ≈ (4π × A²) / λ², where A is the target's silhouette area. This makes forward-scatter bistatic radar useful for detecting stealth targets.
| Parameter | Pulsed | CW/FMCW | Phased Array |
|---|---|---|---|
| Range Resolution | c/(2B) | c/(2B) | c/(2B) |
| Velocity Resolution | PRF dependent | Direct from Doppler | Coherent processing |
| Peak Power | High (kW-MW) | Low (mW-W) | Moderate per element |
| Complexity | Moderate | Low | High |
| Typical Application | Surveillance, weather | Altimeter, automotive | Tracking, multifunction |
- Performance verification: confirm specifications against the application requirements before finalizing the design
- Environmental factors: temperature range, humidity, and vibration affect long-term reliability and parameter drift
- Cost vs. performance: evaluate whether the application demands premium components or standard commercial grades
Frequently Asked Questions
What about multistatic radar?
Multistatic radar uses multiple transmitters and/or receivers. Each TX-RX pair provides an independent measurement of the target's bistatic RCS from a different angle. Combining these measurements improves detection (spatial diversity against RCS fluctuation) and provides target localization from triangulation. Passive multistatic radar (e.g., using broadcast FM or DVB-T transmitters as illuminators of opportunity) is an active area of development.
When is bistatic preferred?
Military applications where the receiver must remain covert, counter-stealth operations where the bistatic or forward-scatter RCS may be larger than monostatic, and passive radar using existing broadcasts. Civilian applications: through-wall radar, ground-penetrating radar with offset transmitter, and passive coherent location systems.