90 likes | 256 Views
Radar Coverage. Radar Coverage. Radio-optical visibility for fixed target height Free space coverage: Target height for fixed RCS Transmission loss: Detectable RCS for fixed target height Transmission loss with or without jammers: Detectable RCS for fixed target height
E N D
Radar Coverage WRAP 0866F
Radar Coverage • Radio-optical visibility for fixed target height • Free space coverage: Target height for fixed RCS • Transmission loss: Detectable RCS for fixed target height • Transmission loss with or without jammers: Detectable RCS for fixed target height • Probability of detection (Pd) with or without jammers for fixed RCS • Post-processing of several probability of protection calculations,Pd-maps (an advanced plug-in extension to the normal Radar Coverage tool) WRAP 0866F
Radar equation • Radar equation where • Pr = Received echo signal power [W] • Pt = Transmitted signal power [W] • Gt = Antenna gain at transmitter • Gr = Antenna gain at receiver • = Radar cross section of the target [m2] • = Wavelength (300/fMHz) [m] • R = Range to the target [m] WRAP 0866F
Radar cross section • Human 1 m2 • Small aircraft 1 m2 • Small boat 10 m2 • Medium aircraft 20 m2 • Jet aircraft 100 m2 • Car 100 m2 • Big ferry ship 10 000 m2 WRAP 0866F
Radar coverage • Wanted probability of detection determines requirement for S/N. • S/N for 50 % and 90 % probability can be used in WRAP • Integration of a number of pulses may be included. Non-coherent integration is assumed. • Normal rotating antenna or fixed azimuth antenna can be selected for calculations on the Transmission loss tab. WRAP 0866F
Radar coverage • Probability of detection can be calculated • Calculation based on Swerling case 1 (slow cross-section fluctuation) • Fluctuation loss means that the probability of detection decreases compared to non-fluctuating target • Fluctuation loss increases as the probability of detection increases WRAP 0866F
Jammers • The total jammer power from each jammer is calculated at each raster point. • Jammer antenna gain, bandwidth, power and transmission loss from jammer to radar are included in the calculations. • If total jammer power is larger than radar sensitivity the minimum detectable RCS is increased. • It is possible to select an interference margin. WRAP 0866F
Example of result WRAP 0866F