Joseph Kostrzewa

TOD versus MRT when evaluating thermal imagers that exhibit dynamic performance

While it is universally recognized that image quality of a thermal sensor is a strong function of spatial uniformity, the metrics commonly used to assess performance do not adequately measure the effectiveness of non-uniformity correction (NUC). Image uniformity is generally not static, particularly if correction terms are updated intermittently (with periodic shuttering) or gradually (with scene-based NUC). Minimum Resolvable Temperature (MRT), the most prevalent test for characterizing overall imaging performance, is poorly suited for characterizing dynamic performance. The Triangle Orientation Discrimination (TOD) metric proposed by Bijl and Valeton, because of its short observation window, provides better capability for evaluating sensors that exhibit non-negligible uniformity drift. This paper compares the effectiveness of MRT and TOD for measuring dynamic performance. TOD measurements of a shutter-based thermal imager are provided immediately after shutter correction and 3 minutes later. The drift in TOD performance shows excellent correlation to drift in system noise.

Beyond Omega: next-generation miniature infrared camera

Three years ago, Indigo Systems launched its Omega camera line, which to this day remains one of the worlds smallest, lightest, lowest powered infrared cameras. The concept of a miniature thermal imager has proven very successful, and thousands of cores have been employed in a number of portable applications, including firefighting, unmanned vehicles, and handheld imagers. A common thread to these high-volume markets is their elasticity-lowering cost substantially enhances demand. Hence the motivation behind Indigo’s newest miniature camera, Photon. Photon is a product family of small and mid-format sensor engines (160x128, 320x128, 320x256) specifically optimized for low cost and high volume. While it shares many of Omegas positive benefits, including remarkably small size, weight, and power, several aspects of the design contribute to it being more affordable than its fore-runner even with four times as many pixels. This paper compares the Photon design to the Omega with particular focus on those aspects affecting manufacturability and cost.

Addressing the challenges of thermal imaging for firefighting applications

By providing visibility through smoke and absolute darkness, thermal imaging has the potential to radically improve the effectiveness and safety of the modern firefighter. Some of the roles of thermal imaging are assisting in detection of victims; navigating through dark, smoke-filled structures; detecting indications of imminent flash-over/roll-over; identifying and attacking the seat and extension of a fire; and surveying for lingering hot spots after a fire is nearly extinguished. In many respects, thermal imaging is ideally suited for these functions. However, firefighting applications present the infrared community some unique and challenging design constraints, not the least of which is an operating environment that is in some ways more harsh than most aerospace applications. While many previous papers have described the benefits of thermal imaging for firefighters, this paper describes several specific engineering challenges of this application. These include large ambient temperature range, rapidly changing scene dynamics, extreme demands on AGC, and large dynamic range requirements. This paper describes these and other challenges in detail and explains how they were addressed and overcome in the design of Evolution 5000, a state-of-the-art thermal imager designed and manufactured by Mine Safety Appliances (MSA) using Indigo System’s Omega miniature uncooled camera core.

Overview of the UL3 Omega uncooled camera and its applications

When it was first introduced two years ago, Indigo Systems Corporations UL3 Alpha, a miniature uncooled infrared camera, set new standards for ultra-low size, weight and power within the thermal imaging industry. Now Omega, the next generation in Indigos UL3 product line, takes advantage of novel algorithms and packaging concepts to further reduce size, weight, and power while still improving performance. These qualities make Omega an ideal candidate for many commercial and military applications, including fire-fighting, law enforcement, industrial inspection, remote surveillance, miniature unmanned aerial vehicles (UAVs), unmanned ground vehicles (UGV), and numerous other possibilities. This paper describes the design, performance and salient features of the Omega camera. Current and future applications of the UL3 product line are also discussed.

A miniature infrared sight for both weapon-mounted and handheld security applications

Thermal weapon sights have been used by the U.S. military for decades. More recently, there has been a growing interest in infrared imagers for paramilitary and civilian applications such as law-enforcement and homeland defense. However, traditional weapon sights are not always ideal products for these applications because they do not typically have form-factor or features allowing them to be readily employed as general-purpose imagers off the weapon. Simply stated, most law-enforcement agencies cannot afford a dedicated sniper scope. Instead, this market demands a thermal imager that can be employed in a variety of situations, both weapon-mounted and handheld. Described herein is a new infrared sight that provides this multi-use capability. Based around the Omega imaging core developed by Indigo Systems, this lightweight system employs a unique housing design that mounts to a weapon rail or tripod or is held comfortably in one hand for use as a short-range “pocket scope”. Key aspects of the design are discussed, with particular focus on ergonomics, human factors, and advanced features that enhance its utility in a multi-use role.

Use of a miniature infrared COTS sensor in a several military applications

The proliferation of small infrared cameras in high-volume commercial applications (e.g. firefighting, law-enforcement, and automotive) presents a tremendous opportunity for truly low-cost military micro-sensors. Indigo Systems Corporations UL3 OmegaTM camera is a commercial off-the-shelf (COTS) thermal imager that offers ultra-small size, light weight, and low power. It employs a 164×120 microbolometer focal plane array (FPA) and is currently entering full-scale production. Furthermore, a 324×240 upgrade is in development. While aimed primarily at the commercial market, small size and low-power consumption make UL3 well-suited for other applications, including miniature unmanned aerial vehicles (UAVs) weapon-sights, and unattended ground sensors (UGS). This paper focuses on the key features of the UL3 family of miniature IR cameras and their utility in soldier systems.

Use of an integrated thermal/visible camcorder for law-enforcement applications

Portable thermal imagers are being utilized with great success in many new and emerging applications, and the law enforcement field in particular is benefiting from thermal imagery. It is quickly becoming common practice for enforcement agencies to apply night-vision technology in such activities as search and rescue, surveillance and stakeout, and suspect pursuit. Thermal cameras, however, do not typically provide an intrinsic means for video recording or for visible imaging. Such capabilities could significantly expand and improve the uses of thermal imaging by law enforcement personnel. For example, surveying the scene of a crime or traffic accident with a thermal sensor offers potential for revealing and documenting clues that otherwise go unnoticed. This paper presents a system that integrates an IR micro-camera with a visible camcorder. The system can display and record live visible and thermal imagery and also capture single-frame snapshots on removable media. This paper also explores the utility of such an integrated camera in various law enforcement scenarios.