The Layered Resilient Navigation System (L-RNS) is a software-defined, sensor-fused PNT architecture designed to maintain accurate navigation continuity across the full spectrum of electronic warfare threats — from broadband jamming to precision spoofing — without dependency on any single signal source. L-RNS operates as a hierarchy of trust: under benign conditions, a multi-constellation, multi-frequency GNSS receiver authenticated via Galileo's OSNMA serves as the primary reference. A Controlled Reception Pattern Antenna (CRPA) continuously steers null patterns toward detected interference sources while preserving gain to authenticated satellites. When interference is detected — by AI-based waveform classifiers running on embedded edge processors — the fusion engine autonomously shifts weight to independent signal layers: Low Earth Orbit (LEO) PNT services (Iridium STL, Xona Pulsar) providing signals up to 1,000 times stronger than GNSS and opportunistic Doppler observables from Starlink and OneWeb mega-constellations immune to GNSS-band jamming; and, as a fully passive backstop, visual-inertial odometry fused with terrain-relative navigation, magnetic anomaly matching, and celestial fixes — none of which rely on radio-frequency signals and therefore cannot be jammed or spoofed. An inertial navigation system with Chip-Scale Atomic Clock (CSAC) holdover bridges transitions between layers with no position discontinuity.

Existing resilient navigation programs address one or two threat layers in isolation; L-RNS is the first architecture to unify all four physically diverse PNT layers into a single, coherent, gracefully degrading solution. The AI-driven fusion arbiter is trainable on real-world interference data (e.g., from Jammertest exercises and Baltic operational logs) and can classify jammer type, estimate bearing for stand-off geolocation via a UAV front-end payload, and re-weight PNT sources in near real time — converting the platform from a passive victim of interference into an active sensor of it. The software-defined implementation means the full capability stack can be delivered as a firmware update to existing multi-band GNSS receiver hardware.

L-RNS is structured as three producible hardware tiers around a common software core. Tier 1 (Retrofit): a software-defined radio front-end module and CRPA adapter card that upgrades existing avionics GNSS units via MIL-STD-1553 or ARINC 429 interface — no chassis change required. Tier 2 (Integrated Unit): a palm-sized (SWaP-C optimized) navigation computer combining a multi-band GNSS chipset, CSAC oscillator, MEMS IMU, LEO PNT modem, and SDR baseband processor on a single compact board for UAV and munitions integration. Tier 3 (Mission System): a rack-mounted variant with ring-laser gyroscope INS, quantum magnetometer, and vision-inertial processor for manned platforms. The AI fusion engine is trained offline and deployed as quantized inference on low-power edge hardware, enabling fielding without cloud connectivity.

Target applications include: (1) Aviation — cockpit navigation and approach guidance for commercial and military aircraft operating in jamming-dense corridors; (2) Unmanned Systems — autonomous UAV navigation in denied areas, including the dual role of maintaining the UAV's own position while geolocating the jamming emitter for follow-on action.