Novel Radio Frequency Sensing Technologies

Detecting and mapping deep subsurface mineral deposits typically requires localized or low-altitude operations. Current state-of-the-art airborne subsurface radar systems are limited to relatively low-altitude and low-speed platforms due to the physical limitations of signal attenuation over distance. Increasing altitude and airspeed would allow for larger areas to be scanned in less time.This topic seeks the rapid development of an advanced airborne system designed for the seamless integration onto high-altitude fixed-wing aircraft. Proposers must address the physical scaling laws of radar propagation through lossy media. According to the radar equations for small targets of a radar cross section of approximately one wavelength, the necessary transmit power scales as a function of range to the fourth power (R4). For instance, transitioning from a 10,000 ft baseline to a 40,000 ft operational altitude represents a 4x increase in distance, nominally demanding a 256x increase in radiated power to maintain equivalent subsurface imaging performance.Due to the higher power requirements at higher altitudes, system designs must prioritize transmit power scaling, advanced antenna structure designs, and robust heat dissipation systems.To facilitate rapid, modular deployment across diverse airframes without requiring permanent, costly aircraft modifications, the entire system must be designed as a fully self-contained payload. It must utilize independent, internal power generation and an edge computational architecture. Key technical challenges that proposers must address include: 1. High-Power Transmitter & Power Scaling: Engineering and validating a highly reliable kW-class RF power amplifier.2. Aerodynamic & Structural Antenna Design: Designing and reinforcing an externally deployable or structurally integrated antenna system capable of withstanding aerodynamic loads at relevant velocities (~400 knots) and altitudes (~40,000 ft).3. Thermal Dissipation & Management: Integrating passive or active high-capacity heat dissipation systems to mitigate thermal loads under sustained high-power transmit cycles.4. RF Shielding & Electromagnetic Compatibility (EMC): Implementing advanced RF shielding and electrical isolation to guarantee zero electromagnetic interference with the host aircraft’s flight navigation, control, and mission avionics.5. Field-Programmable Gate Arrays (FPGAs) & Edge Processing: Selecting FPGAs and processing techniques that can handle increased signal propagation delays, modified waveforms, and real-time tomographic data processing at high standoff distances.