What are the reported or estimated RCS values for the F-35 and F-22 across different radar bands?
Executive summary
Published and community estimates place both the F-22 and F-35 in the “very low” RCS category but disagree on exact magnitudes and how they change by radar band: multiple unclassified sources report frontal X‑band equivalencies ranging from roughly 10^-4–10^-2 m^2 for the F-22 and roughly 10^-3–10^-2 (and sometimes 5×10^-3 or lower) for the F-35, but those numbers vary with aspect, frequency band, measurement method and modelling assumptions stealth-aircraft-rcs.htm" target="blank" rel="noopener noreferrer">[1] [2] [3] [4]. Public reporting and open‑source simulations consistently warn that RCS is frequency‑ and aspect‑dependent, and that precise classified measurements are not available in the public domain [5] [6] [7].
1. Reported headline figures: marble vs golf‑ball analogies
Several widely cited references use simple analogies and headline figures: GlobalSecurity cites the F-22’s frontal signature as “-40 dBm2” and the F-35’s as “-30 dBm2,” framed as marble‑ and golf‑ball‑sized signatures respectively [1], while Military Embedded Systems and some forum summaries translate popular claims into metric numbers — for example stating an F-35 RCS ≈0.005 m^2 and an F-22 ≈0.0001 m^2 [2] [3]. These headline numbers appear across unclassified outlets but are not consistent with one another and reflect different assumptions about aspect and radar band [3] [2].
2. Frequency dependence: VHF/L/S/X matter; X‑band gets the most attention
Open modelling and academic simulation work emphasize that RCS varies strongly with radar frequency; many public simulations sample VHF, L, S and X bands and show different mean/median RCS across those bands [7] [8]. ResearchGate summaries of F-35 polar plots at ~10 GHz (X‑band) report mean frontal values around -11 dBsm (≈0.008 m^2) for certain model assumptions [4], while authors of RCS simulation papers caution that radar absorbent materials and measurement conditions would typically reduce those simulated numbers further [4] [6].
3. Aspect, sensors and real‑world caveats: rear and side views can be much larger
Multiple sources stress that all quoted RCS values are highly aspect‑dependent and that rear aspects (engine nozzles, exhausts) and certain side views can produce substantially larger returns; Military Embedded Systems explicitly notes the F-35’s rear signature grows because of exhaust nozzles [2]. Forum and simulation discussions reiterate that onboard antennas, intakes, weapons bays and emitted RF can dominate observable signature if oriented toward a radar or operating in the same band [1] [9].
4. Relative comparison across bands: F‑22 generally lower in X/targeting bands, F‑35 optimized for multiband tradeoffs
Analysts summarized in The National Interest and open discussion forums conclude the F-22 typically achieves lower RCS in fighter targeting/search bands (notably X‑band) and was optimized for frontal air‑dominance stealth, while the F-35 reflects design tradeoffs for multirole survivability, maintainability and cost that influence band‑dependent performance [10] [11]. This accords with modelling work showing both fighters are “very low” in X but that the F‑22 tends to outperform the F‑35 in frontal X‑band returns in most public analyses [10] [3].
5. What the public record cannot tell: measurement uncertainty and classified data
All available unclassified sources are model results, forum summaries or journalistic reporting; multiple voices in the open literature warn that true, instrumented RCS measurements (especially across bands and aspects) are classified and that published values are best‑effort estimates that depend on modelling fidelity, RAM assumptions and post‑processing choices [6] [9] [5]. Where sources disagree — e.g., whether an F-35 frontal X‑band mean is ≈0.005 m^2 versus ≈0.0015–0.008 m^2 — the divergence reflects different modelling parameters and the absence of an authoritative public measurement [2] [3] [4].