Real-time Hyperspectral Imaging For the Detection of Threat Materials

There is a whole world out there, veiled by visible light, that contains information vital to our health and safety. Hyperspectral imaging (HSI) offers a means to see into this world paradoxically obscured by light, to differentiate among its building blocks and distill it into actionable data. One area that requires fast, reliable detection in real-time with a high degree of autonomy is hazardous materials.

To address this need, ChemImage and the Carnegie Mellon Robotics Institute collaborated to develop a novel, adaptable, short-wave infrared (SWIR) HSI system for rapid standoff detection of hazardous materials (e.g., explosives, narcotics, etc.). At the heart of this system is the Conformal Filter (CF), which is a liquid crystal (LC)-based tunable filter that transmits multi-band waveforms. Building on concepts of multivariate optical computing, the CF is tuned electrooptically and dynamically to mimic the functionality of a discriminant vector for classification. The resulting integrated detector response approximates the response of conventional HSI with only two discrete measurements instead of hundreds or thousands. Real-time detection is achieved by operating two CFs in tandem within a dual polarization (DP) system, exploiting the polarization sensitivity of the LC filters and allowing for simultaneous acquisition of the compressed hyperspectral imagery. This improved sampling rate coupled with advanced object recognition, semantic scene understanding, and image reconstruction algorithms enables real-time (i.e., >10 detection fps), on-the-move detection of targets.

Problem and Opportunity

In today’s society, there is a growing need for immediate, adaptable, safe, autonomous, standoff detection of chemical, explosive and illicit drug threats to address the resurgence of worldwide terroristic activity.

Organizations like the Department of Homeland Security (DHS) and the Drug Enforcement Agency (DEA) encounter daily battles against terroristic threats and illegal narcotic smuggling that would benefit from such capabilities. Additionally, state and local law enforcement agencies demand technologies that aid in detecting and classifying unknown materials in hazmat situations and crime scene investigations. Security teams responsible for safeguarding large public venues, like stadiums during popular sporting and politic events, also need sensing capabilities to detect a wide variety of threat materials live and at safe distances. Accordingly, the demand for real-time, autonomous standoff detection of threats is ever present and growing for numerous end users.

HSI sensors have been used to detect and identify a variety of targets in the presence of complex backgrounds at a standoff distance. Unfortunately, current generation sensors are typically large and slow, costly to field, lack adaptability to changing threats, and have limited sensitivity and specificity. Evolving the next generation of HSI technology to address current generation sensor limitations will attend to the growing detection needs of numerous local, state and federal law enforcement agencies.

ChemImage is at the forefront of the development and validation of HSI sensors capable of standoff, rapid detection of chemical, explosive and illicit drug threats in complex, real world environments.

One of ChemImage’s most recent advancements is a novel, real-time (>10 detection fps), adaptable, compressive sensing SWIR-HSI sensor based on dual polarization conformal filter (DP-CF) imaging technology. DP-CF is capable of being configured in a handheld or vehicle-mounted sensor that provides both stationary and on-the-move standoff detection of threat residues, including people and vehicles. DP-CF may prove ideal for route clearance or combat patrols, helping soldiers to quickly detect if there is danger ahead. It is anticipated to have an impact on maintaining military forces’ competitive advantage, especially when fully matured into a lightweight, compact, handheld or wearable system for the detection of critical targets in the presence of complex backgrounds.

In addition to defense and law enforcement applications, DP-CF is anticipated to support commercial sensing application needs such as quality assessment of pharmaceuticals, food analysis, precision agriculture, textiles analysis, evaluation of plastics, semiconductor defect inspection, illicit drug screening in mail, and forensic trace evidence examination.

To learn more about HSI sensor limitations click here to download our full report on Real-time Hyperspectral Imaging.