- The U.S. Army issued a sources sought notice to assess industry capability for a non-GNSS optical tracking system known as T-SPOT for test ranges.
- The concept aims to provide accurate time-space-position data in GPS-denied environments using passive optical sensors and landmarks.
The United States Army has issued a sources sought notice to survey industry capabilities for a new optical tracking concept designed to support weapons and aircraft testing when satellite navigation is unavailable or disrupted.
According to the notice, Army Contracting Command–Orlando is conducting market research on behalf of the Test Resource Management Center’s Test and Evaluation/Science and Technology program to assess the viability of a concept known as Time-Space-Position Optical Tracking, or T-SPOT. The effort focuses on whether T-SPOT could serve as a reliable Time-Space-Position Information, or TSPI, “truth sensor” on test ranges operating in Global Navigation Satellite System-denied environments.
The program background highlights growing concern over reliance on satellite-based navigation. As noted in the notice, modern weapon systems and test platforms increasingly depend on GNSS for positioning and navigation, while U.S. adversaries are investing more resources in jamming, spoofing, or denying those signals. This trend has created a need to test navigation and guidance systems under realistic GNSS-denied conditions.
Current non-GNSS testing options have limitations. Live test ranges often provide either poor TSPI accuracy over large areas or moderate accuracy over limited zones. Anechoic chambers can deliver high-quality TSPI but restrict platform movement and do not fully reflect real-world operating conditions. The Army said this gap drives the need for a highly accurate, non-GNSS TSPI solution that can operate across large outdoor test ranges.
T-SPOT is envisioned as an optical system that estimates a system under test’s position by comparing time-stamped imagery of known landmarks with their surveyed locations. According to the description, the approach relies entirely on passive components: visual sensors carried by the test aircraft or vehicle and terrestrial landmarks that require no power or active emissions.
Army officials noted that this architecture offers a clear separation between TSPI measurement and navigation functions, reducing the risk that the technology could be repurposed for operational navigation rather than test instrumentation. The system may use a mix of pre-existing natural or man-made landmarks and purpose-installed fiducials, with GNSS permitted only before and after testing for surveying purposes.
The sources sought notice outlines an anticipated prototype effort focused on architecture development, concept of operations, and a detailed trade space analysis based on modeling and simulation. The goal is not to deliver a fielded system, but to determine whether and how a future T-SPOT system could meet defined performance goals.
According to the Army, a mature T-SPOT concept would aim to deliver near-continuous, three-dimensional TSPI accuracy comparable to Real-Time Kinematic GNSS systems. The system would initially operate during daylight and good visibility, with a longer-term goal of night and all-weather capability. It would also need to integrate temporarily with crewed aircraft operating at altitudes typical of U.S. Air Force cargo and single-engine training aircraft, with an eventual path toward use on uncrewed aerial systems.