ISL scientists and engineers have delivered solutions, designs, and prototypes for surveillance, communications, and signals intercept systems, many incorporating novel adaptive processing. Our customer base is primarily the Department of Defense including Navy, Air Force, Army, DARPA, and industry contractors.

Urban Sensing and Geolocation

ISL is developing innovative, knowledge-based solutions to allow US forces to maintain superiority in the urban battlefield common in today’s engagements. These solutions exploit the complex urban scattering environment to accurately localize a target. Active sensors (e.g., radar) can exploit knowledge of the multipath in the urban environment to locate moving targets that would otherwise be undetected due to blockage using conventional systems. By exploiting the knowledge of the unique propagation environment the target can be accurately tracked even when no line-of-sight signal is present.


Urban geolocation solutions can accurately locate an emitter by exploiting the unique multipath and blockage at a specific site. This solution combines model predictions of the propagation environment with signal measurements to provide an accurate solution of the emitters location.

Persistent Surveillance Platform Solutions

Today’s surveillance missions require sensing platforms that can remain on station for long periods of time. This requires substantial endurance and payload capacity with the flexibility to meet the needs of a given mission. ISL has solutions that include lighter than air (LTA) aerostats and airships, long-endurance unmanned aircraft, and rapid-insertion portable towers. For further details see Aeronautical & Space Systems.

Passive Coherent Location System (PCLS)

ISL is developing a Passive Coherent Location System (PCLS) for the Air Force Research Laboratory. Instead of using its own transmitter, this passive detection and tracking system processes common broadcast transmissions such as FM radio and television. The system is designed to track missile launches and has the capability to track aircraft and, in some cases, ground or sea-based moving targets.

ISL has established a test facility at its San Diego Laboratories comprised of a rooftop antenna array, analog signal conditioning, and digital processing. The system is modular, configurable and programmable to satisfy customer target tracking objectives and the local radio frequency broadcast environment. Our high fidelity simulation forecasts system performance, assists system configuration, supports development of novel high-resolution modes, and assists in the data interpretation. The system has military, homeland defense, and commercial applications.