ECM Phantom Targets: Visualisation · Signals from the Periphery

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Target range

60 km

Jam / signal

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Burn-through

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Track

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ECM · THE PHANTOM-TARGET BENCH
the echo pays a round trip; the jammer pays one way
1/R⁴ against 1/R², and that is the whole art
pink = what the receiver was handed
mint = the one aircraft that is really there
close the range and the radar wins it back

Part

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Evidence

fact ⇄ what kind of claim · live

The echo falls as 1/R⁴; the jammer, one way, as 1/R²

the radar range equation · the structural advantage of ECM

MODELLED

Burn-through exists no matter how strong the jammer

different slopes must cross · power only moves it inward

MODELLED

Chaff: resonant dipoles, first dropped over Hamburg, 1943

huge return, then it flies with the air within about a second

MEASURED

Repeaters walk range gates; DRFM replays coherent copies

fielded, open-literature engineering, not speculation

MEASURED

Every technique here has a published counter

leading-edge track, frequency agility, Doppler notch, home-on-jam

MEASURED

The Range Fouler form asks about electronic attack

a printed field, between the trackfile and the shape checklist

REPORTED

DOW-UAP-D58 logged noise jamming in the same encounter

establishes the environment, identifies nothing

REPORTED

DOW-UAP-D56: negative ES, radar track and IFF

the counter-case · no electronic signature at all

REPORTED

Does any of this explain a given sighting?

ECM writes to a receiver, not to a lens or an eye · open

READING

View

Electronic attack · which one do you run?

BASELINE

▶ One exponent runs everything here. The echo pays the round trip and falls as 1/R⁴; the jammer pays one leg and falls as 1/R².

The engagement

Target range…

The dial that decides the contest. Every kilometre closer multiplies the echo by more than it multiplies the jammer, which is why closing is the radar's only unanswerable move.

Target RCS…

How much of the pulse the airframe throws back. A fighter head-on is a few square metres; a bird or a small drone is a hundredth of that, and sits under the noise long before anything jams.

Jammer ERP…

Effective radiated power of the pod: transmitter times antenna gain. Note how little it takes at long range, and how fast that advantage evaporates as the radar closes.

Radar peak power…

The radar's side of the ledger. Ten times the power buys only 1.8 times the detection range, because of the same fourth power that makes jamming cheap.

Pull-off rate…

How fast the repeater grows its delay, in metres of apparent range per second. Set it absurdly high: nothing has to accelerate, because nothing is there.

False targets…

How many coherent copies the DRFM replays. They can be given any kinematics at all, but they cannot be given a different bearing.

ECCM · the radar's published answers

Leading-edge tracka repeater always answers late

Doppler / MTI notchrejects returns near zero radial velocity

Frequency agilitya spot jammer answers a radar that moved

Home on jamthe noise strobe is still a true bearing

Display

Phantoms and chaff

Beam and burn-through ring

Labels

Readout · exact from your dials

Skin return S

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Jammer J

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Noise floor N

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S / (J + N)

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J / S

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Burn-through

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False target looks like

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Tracker

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What is measured vs modelled here

Measured: the techniques themselves. Chaff has been flown since 1943, range-gate pull-off and DRFM false targets are fielded equipment described in the open engineering literature, and so is every counter on this panel. Modelled: every number on screen, from a generic X-band radar and a textbook detection model. Reported: the quoted lines in the Debrief view, from the Navy's released Range Fouler files. Reading: whether any particular sighting was electronic attack. This instrument shows what ECM can produce; it identifies nothing.

The radar on this bench

A deliberately generic X-band set: 10 GHz, 33 dBi antenna, 1 MHz receiver bandwidth, 5 kW peak by default, 800 K system noise temperature, 4 dB of losses, 128 pulses coherently integrated, and detection declared at 13 dB. Those are textbook teaching figures chosen to land near the published detection ranges of fighter radars against a few square metres, not the parameters of any fielded system. Jamming enters as J = ERP·G·λ²/((4π)²R²Lj) times the fraction of the jammer's bandwidth that falls inside the receiver, and detection is declared when n·S/(N+J) clears the threshold. Burn-through is then a quadratic in R², solved exactly rather than searched for.

Where this drawing takes liberties

The range axis in the engagement view is logarithmically compressed and the aircraft are drawn hundreds of times oversized, or two 17 m jets 60 km apart would be invisible specks. The beam is drawn far wider than 3.3°. The scope's phosphor, scan rate and blip sizes are chosen for legibility, not fidelity to any display. Chaff is modelled as a single cloud with a decelerating radial velocity and an RCS of N×0.15λ², the random-orientation average for a half-wave dipole, which is an approximation. Angle deception (cross-eye and its relatives) is not modelled: the false targets here take range and Doppler only, which is why they all sit on one bearing.

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drag = orbit · scroll = zoom · the pink copies are what the radar believes