Suppression of enemy air defenses: activity that neutralizes, destroys, or temporarily degrades surface-based air defenses. Destruction removes a site for the rest of the mission; suppression degrades it only while the suppression is applied.
Lethal: anti-radiation missiles (HARM) homing on the radar's emission, or weapons on a located site. Non-lethal: electromagnetic attack — noise jamming, including a standoff jammer. Yes: a HARM in the air gives operators reason to shut the radar down, and a silent radar is suppressed, not destroyed — it comes back when the threat passes.
Suppression lasts only while the suppressor is on station, so it opens and closes in time. A package gains only for the part of its time inside the site's lethal zone that falls inside the window; a late package, or a long path through the zone, flies the rest exposed. Fixes: leave earlier, shorten the path through the zone, or lengthen the window.
The radial velocity is \(v_r = v\cos\alpha\). Fly perpendicular to the line of sight (\(\alpha = 90^\circ\)) and \(v_r \to 0\), so \(f_d = 2v_r/\lambda \to 0\): the echo lands in L5's MTI notch with the ground clutter and is canceled with it. The notch is narrow, so the heading must be held within a few degrees of the beam.
The pattern's sharpest spike sits exactly at the beam: about −3 dBsm against −15 dBsm nose-on, 12 dB brighter. With \(R \propto \sigma^{1/4}\) that doubles the range at which a radar mode that does not rely on Doppler can see you. The notch wants exactly beam, and the signature punishes exactly beam.
Inside the MEZ but outside the LEZ (L32): with your tail on the site, the missile flies a stern chase and runs out of time of flight. Inside the LEZ, \(R_{\text{LEZ}} = (v_m - v_t)t_{\max}\), it catches even a target running straight away. Dragging holds the cold heading to spend the missile's energy; the endgame belongs to chaff (L18) and flares (L24).
Two ranges: the echo still travels the target's range \(R_t\) both ways, but the jamming travels the jammer's range \(R_j\) one way, and \(R_j\) stays fixed while \(R_t\) closes. Two gains: the radar hears the target through its mainbeam \(G_r\) but the jammer through the gain it points toward the jammer, \(G_r'\).
\(\dfrac{J}{S} = \dfrac{4\pi P_jG_jR_t^4}{P_tG_t\sigma R_j^2}\cdot\dfrac{G_r'}{G_r}\cdot\dfrac{B_r}{B_j}\) — the echo's two-way loss \(R_t^4\) over the jammer's one-way loss \(R_j^2\), times the gain ratio and L17's bandwidth factor.
Put the jammer on the target: \(R_j = R_t = R\) and \(G_r' = G_r\). Then \(R_t^4/R_j^2 = R^2\) and the gain ratio is 1, leaving \(J/S = 4\pi P_jG_jR^2 B_r/(P_tG_t\sigma B_j)\). With L17's Quick Problem numbers both forms give +14.5 dB at 30 km and a 17.8 km burn-through.
\(R_{bt} = \left[\dfrac{10\,P_tG_t\sigma R_j^2 B_j}{4\pi P_jG_j(G_r'/G_r)B_r}\right]^{1/4}\), the target range where \(J/S\) falls to 10 (+10 dB). A fourth root because only the echo is two-way; the jammer's \(R_j^2\) is a constant, fixed by the orbit.
When it sits on the target's azimuth, within half a beamwidth — on the jammer's side of the radar. Then \(G_r'/G_r = 1\) (0 dB). Anywhere else the jamming enters through a sidelobe and \(G_r'/G_r\) is the sidelobe level, typically −25 to −35 dB. A target on the far side of the radar from the SOJ is on the same line but not in the mainlobe.
\(R(\phi) = \min(R_{det}, R_{bt}(\phi))\): the sidelobe burn-through range around most of the circle, and a deep, narrow notch one beamwidth wide on the jammer's azimuth, where it falls to the mainlobe burn-through range. That notch is the strobe — on the radar's display, a bright radial line of jamming pointing at the jammer.
The part of the strobe between the mainlobe and sidelobe burn-through ranges: a striker there is hidden, while a few degrees to either side the same radar sees it. Its width at range \(R\) is about \(R\,\theta_B\) — for a 5° beam, about 2.6 km at 30 km. A corridor, not a sky.
\(R_{bt} \propto R_j^{1/2}\): the one-way \(R_j^2\) inside a fourth root. Four times the standoff only doubles burn-through, so backing a jammer off to clear the missile zones is cheap — and pulling it in buys little.
\(R_{bt} \propto (G_r'/G_r)^{-1/4}\): every 10 dB of sidelobe is a factor of \(10^{10/40} = 1.78\) in burn-through range, and 30 dB is 5.6. Lower sidelobes push the radar's burn-through out; flying the jammer's azimuth wins that whole factor back for free.
L15's sidelobe cancelers (an auxiliary antenna nulls the jammer), sidelobe blankers, and ultra-low sidelobes all attack the sidelobe path. None of them can remove a jammer sitting in the beam the radar is looking through — so the mainlobe is the one door EP cannot close, and the route rides the strobe.
(1) Orbit outside every MEZ plus a margin — the SOJ radiates, so it will be found. (2) One jammer beam, one victim: a directional SOJ holds its transmit mainlobe on one radar, and the others are (to first order) unjammed. (3) The route rides the victim's strobe. (4) The other sites' zones are crossed inside the SEAD window, or avoided.
The radar's receive lobes, \(G_r'/G_r\), decide where around a jammed radar the jamming bites hardest: the mainlobe on the jammer's azimuth (the strobe), a sidelobe elsewhere. The jammer's transmit beam, \(G_j\), decides which radar is jammed at all: a directional SOJ aims its ERP at one victim at a time. A radar outside that beam still hears the jammer faintly through its sidelobes; the Final Project treats it as unjammed, a stated simplification.