CHARLOTTEíS WEB: In-Situ Web of Mechanical, RF, Thermal, and Spectral Sensors for Dead Reckoning

To improve the accuracy of dead reckoning systems for hypersonic vehicles, Rhea Space Activity (RSA) and the University of Colorado Boulder (CU) propose CHARLOTTEíS WEB: In-Situ Web of Mechanical, RF, Thermal, and Spectral Sensors for Dead Reckoning. CHARLOTTEíS WEB is a State-of-the-Art (SOTA) dead reckoning algorithm that fuses a web of in-situ sensors to reduce drift error present in Inertial Measurement Units (IMU) used for extended autonomous navigation. These sensor measurements will feed into a Kalman Filter to estimate the state dynamics of hypersonic vehicles (HV). A unique feature of this implementation is the incorporation of the onboard spectrometer for plasma characterization, a primary focus of the Phase I effort. Through a merging of different sensors, including spectrum, temperature and altitude, CHARLOTTEíS WEB will provide more accurate estimates of the HVís velocity using the light produced by the plasma surrounding the vehicle. These sensors will feed into environmental and plasma characterization models that correlate the speed of the vehicle to the light spectrum produced by the plasma, taking advantage of the spectrumís strong correlation between the speed of the vehicle and density of the surrounding medium. CHARLOTTEíS WEB will be enabled by the following:State Estimation from Plasma Spectral Characterization: CHARLOTTEíS WEB will use spectrometers to provide robust and redundant data sources for measuring the plasma sheath surrounding the HV. These in-situ measurements will feed into plasma models that correlate the spectrum to the speed of the vehicle.Integration with In-Situ Sensor Suite: CHARLOTTEíS WEB will incorporate its spectrometer into a system with a ìwebî of other novel sensor types. Stress/strain gauges to provide information on mechanic loads experienced HV experience, which inform changes in velocity, spin rates, and acceleration; altimeters and thermal sensors to inform estimates of atmospheric environmental characteristics and provide additional information as inputs to plasma dynamics estimates.Sensor Web Fusion: CHARLOTTEíS WEB will fuse measurements sensor data sources and modelling algorithms into a Kalman Filter to provide highly accurate dead reckoning estimates of the HVís state information.