SLS-402 · SNS
Resonance
Passive acoustic array. Listen-only detection, classification, and bearing on surface and subsurface contacts. Resonance hears propeller cavitation long before any radar paints the target — and never emits a thing.
Resonance is a large-aperture coherent hydrophone array with 360° azimuthal coverage, detecting and classifying propeller cavitation and machinery lines at passive standoff range.
DEMON and LOFAR tonal processing estimates shaft RPM, blade count, and vessel class from blade-rate harmonics, with narrowband and broadband false-alarm suppression. Tracks hand off to Tidefall as bearing, class, and confidence.
The payload rides a UUV — Sounder or Backeddy — or moors as a distributed low-power node field. Array integration is in work through mid-2026.