TRIDENT™
Traveling-Ionospheric Disturbance Evaluation Tri-wave
Traveling ionospheric disturbances (TIDs) occur when tremendous energy deposits into the atmosphere, generating acoustic and gravity waves that propagate into the ionosphere and create distinctive mechanical and electromagnetic signatures. These phenomena originate from both natural events (volcanic eruptions, earthquakes, severe weather) and human activities (fast moving aerial vehicle transit, rocket launches/reentries, explosions).
Accurate, real-time analysis of these TID signatures would enable defense agencies to detect hypersonic movers and other human activities, deduce their properties and ultimately address both established and emerging threats in national defense.
FAST MOVING OBJECT DETECTION
To detect these ionospheric disturbances, Orion, an Arcfield company, has developed TRIDENT, an advanced high-frequency (HF) radar system designed to detect and characterize TIDs generated by objects traveling faster than Mach 2. The TRIDENT system leverages a sophisticated network of HF radar technology to detect these perturbations, capturing data on gravity waves propagating from rapidly moving point sources. Analysis of these ionospheric signatures can be used to locate the source of the disturbance, similar to how a ship’s wake is observed and traced to the vessel creating the disturbance.
ARCHITECTURE AND PERFORMANCE DESIGN
A TRIDENT installation consists of two transmitters and four receivers arranged in a strategic layout. This architecture enables eight total reflection pairs, allowing the Doppler shift between transmitted and received signals to be analyzed for studying TIDs. Additionally, one transmitterreceiver pair is positioned closely together, functioning as a standard ionosonde. The system’s over-determined design enhances reliability, making it well suited for operational use cases.
TRIDENT functions as an operational system to deliver three types of data:
High-precision characterization of TIDs, including wave period, phase speed, horizontal and vertical wavelengths and propagation direction
Characterization of the vertical structure of the ionosphere, similar to an ionosonde
Observation of mid-latitude spread F phenomena caused by ionospheric irregularities
APPLICATIONS AND VALUE
TRIDENT improves the accuracy of forecasting over-the-horizon-radar performance and ionospheric impacts on systems such as satellites and HF communication systems. The system augments real-time ionospheric models that can make frequency management systems more effective.
With the ability to detect and characterize fast-moving objects from their ionospheric waves, Orion’s novel instrumentation and modeling solution will be the keystone for future early warning systems supporting national defense readiness.
