The low-cost day and night imaging capability of uncooled infrared imagers significantly enhances the situational awareness capability of an unattended ground sensor. BAE Systems has leveraged its Standard Camera Core 500 product to develop an advanced imager, the MIM500TM, for use in unattended ground sensors and other military applications. Key improvements implemented in the MIM500TM include reduced operating power, pixel synchronization to an external clock, variable frame rate, a ruggedized mechanical design, a new reduced power standby mode, and electronic zoom,. This paper presents an overview of the MIM500TM design, it describes MIM500TM features that enhance the capability of unattended ground sensors, it discusses imaging performance data, and it provides an overview of current MIM500TM applications.
Recent advances in the state of the art of IR imaging have made it possible to provide ultra-long range detection, recognition, and identification performance with small, low cost, yet rugged camera systems. As the trend in IR technology has moved toward larger format uncooled microbolometers, BAE Systems has developed a PMC300TM camera system based on a 640x480 uncooled microbolometer detector. The system is capable of detecting humans at distances in excess of 4km, has a sensitivity of better than 50mK, is compact, has low power consumption, quick start times and can operate in desert and polar climates. This paper will discuss the PMCTM performance capabilities, design considerations, design improvements, and its varied applications.
Designed to fulfill a critical inspection need for the Space Shuttle Program, the Infrared On-orbit RCC Inspection System (IORIS) can detect crack and surface defects in the Reinforced Carbon-Carbon (RCC) sections of the Space Shuttle’s Thermal Protection System (TPS). IORIS performs this detection by taking advantage of the natural thermal gradients induced in the RCC by solar flux and thermal emission from the Earth. IORIS is a compact, low-mass, low-power solution (1.2cm3, 1.5kg, 5.0W) for TPS inspection that exceeds existing requirements for feature detection. Taking advantage of ground-based IR thermography techniques, IORIS provides the Space Shuttle program with a solution that can be accommodated by the existing inspection system. IORIS augments the visible and laser inspection systems and finds cracks that are not easily measurable by the other sensors, and thus fills a critical gap in the Space Shuttle’s inspection needs. Based on crack IR signature predictions and on-orbit gradient expectations, IORIS can achieve crack detection over approximately 96% of the wing-leading edge RCC (using multiple inspections in an orbit period). This paper discusses the on-orbit RCC inspection measurement concept and requirements, and then presents a detailed description of the IORIS design.
BAE Systems is the leading producer of uncooled microbolometer based thermal imaging engines in the world. Initial investments to develop and produce uncooled infrared (IR) technology were primarily driven by military applications, but it was the commercial market with the potential for large product volumes which provided BAE Systems with the business model required for investment in uncooled IR technology. This paper reviews the heritage of BAE Systems technology and current products and is an example of the success of a Dual-Use technology area which DARPA invested in during the 1990s.
This paper describes the inherent advantages of IR uncooled imagers in general, and the SCC500 in particular, for homeland defense. The SCC500 is a small, lightweight, low power, high performance uncooled imager that began production shipments in the spring of 2003. Key technologies described are dynamic range control, contrast enhancement and electronic zoom. Availability of these advanced features in production products are also described.
BAE SYSTEMS produces hundreds of low cost, high performance, uncooled IR imagers each month for use in commercial and military applications. The production process of each imager includes several steps that begin at the wafer level and end at an in-camera test. Each step is critical to end yield improvement by detecting failure at various stages in the production flow. Both automated test equipment and an integrated database system are essential at each phase to efficiently build and automatically configure cameras for each customer. This paper discusses the process and tools used to reliably test and ship uncooled thermal imagers in addition to specific methods and calculation techniques for characterizing key performance parameters such as Responsivity, Noise Equivalent Temperature Difference, and Operability.
BAE SYSTEMS has made tremendous progress in uncooled technology and systems in the last year. In this paper we present performance results and imagery from our latest 640x480 and 320x240 small pixel focal plane arrays. Both were produced using submicron lithography and have achieved our lowest NETDs to date. Testing of the 320x240 devices has shown TNETDs of 30mK at F/1. Video imagery from our 640 x 480 uncooled camera installed in a POINTER Unattended Aerial Vehicle is also shown. In addition, we introduce our newest commercial imaging camera core, the SCC500 and show its vastly improved characteristics. Lastly, plans for future advancements are outlined.
Starting in the early 1990’s, BAE SYSTEMS began a significant investment in the development of MicroIR Uncooled Microbolometers. 160 x 120, 320 x 240, and 640 x 480 focal plane array (FPA) technology advances in both large pixel and small pixel format have driven Noise Equivalent Temperature Difference (NETD), power, size, weight, and price lower. These improvements have resulted in many new applications that previously could not afford larger, heavier, costlier cooled systems. While advancements in state of the art performance have been published regularly at Aerosense and other industry forums, far less has been discussed on the performance advances that have occurred as a result of volume manufacturing. This paper describes the improvements in performance that have been a result of BAE SYSTEMS leadership position in MicroIR microbolometer manufacturing. With over 15,000 units shipped through 2002, ranging from Standard Imaging Modules (SIM) to Standard Camera Cores (SCC) to complete imaging systems, the cumulative expertise gathered from this manufacturing experience over the past seven years has also pushed the state of the art system performance, in ways that single/small quantity technology demonstrators never could. Comparisons of temporal NETD, spatial NETD, dynamic range, operability, throughput, capacity, and other key metrics from early manufacturing lots to the present will be presented to demonstrate the advances that can only be achieved through volume manufacturing.
BAE SYSTEMS has been developing and producing uncooled microbolometer sensors since 1995. Recently, uncooled sensors have been used on Pointer Unattended Aerial Vehicles and considered for several unattended sensor applications including DARPA Micro-Internetted Unattended Ground Sensors (MIUGS), Army Modular Acoustic Imaging Sensors (MAIS), and Redeployable Unattended Ground Sensors (R-UGS). This paper describes recent breakthrough uncooled sensor performance at BAE SYSTEMS and how this improved performance has been applied to a new Standard Camera Core (SCC) that is ideal for these unattended applications. Video imagery from a BAE SYSTEMS 640x480 imaging camera flown in a Pointer UAV is provided. Recent performance results are also provided.
320×240 and 640×480 small pixel uncooled microbolometer focal plane arrays have been developed that reduce overall sensor size, weight, power consumption, and cost. At the same time, these sensors still provide the high quality image resolution needed for target recognition and identification. These newly developed small uncooled thermal imaging sensors are being demonstrated in several attended and unattended sensor applications that include Unattended Ground Sensors, Micro Air Vehicles, and Infrared Helmet Sights. This paper describes recent developments at BAE SYSTEMS in uncooled microbolometer sensor technology for unattended sensor applications and presents the latest performance and image data for our 2nd generation systems.
BAE SYSTEMS has designed and developed MicroIR microbolometer focal plane arrays (FPAs) in three formats (160x120, 320x240, and 640x480) and with two different pixel sizes (46micrometers and 28micrometers ). In addition to successfully demonstrating these FPA technologies, BAE SYSTEMS has produced and delivered thousands of 320x240 (46micrometers pixel) imaging modules and camera cores for military, thermography, firefighting, security and numerous other applications throughout the world. Recently, BAE SYSTEMS has started production deliveries of 160x120 (46micrometers ) systems, demonstrated 320x240 and 640x480 second-generation (28micrometers ) imaging, and demonstrated second-generation thermoelectric cooler-less operation. This paper discusses these recent accomplishments and, when possible, provides quantitative NETD and performance data for our newly developed FPAs and systems. Video will be shown to demonstrate sensor performance capabilities.
Uncooled microbolometer thermal imaging sensor technology has begun to successfully address military, government and commercial applications in the real world. BAE SYSTEMS, located in Lexington MA, has been involved in the design and development of uncooled IR technology since the early 1980s. Our current MicroIRTM products are based on vanadium oxide (VOx) microbolometers. Thousands of uncooled microbolometer thermal imaging sensors are now being produced and sold annually. A the same time, applied research and development on the technology continues to improve the basic products and make them suitable for new applications. In this paper we report on the status and improvements achieved in the MicroIRTM product line, based on 320 X 240 element and 160 X 120 element FPA's with 46 μm pixel pitch. Other near term MicroIRTM products include 320 X 240 and 640 X 480 FPA's with 28 micrometers pixel pitch and measured sensitivities below 50 mK. In the systems area we discuss development and testing of a Light Thermal Weapon Sight (LTWS) for the U.S. Army, being developed by BAE SYSTEMS in partnership with Thales, based upon our uncooled MicroIRTM focal plane arrays (FPA) and systems. The LTWS prototypes were based upon our Standard Imaging Module SIM200, which employs our LAM2C, 320 X 240 element, microbolometer FPA. Finally we discuss the 480 X 640 element FPA and its application to the Heavy Thermal Weapon Sight application.
Sanders IR Imaging Systems (IRIS), a Lockheed Martin Company, has made recent improvements in high performance uncooled IR focal plane arrays and systems. This paper provides performance results for three of these new FPAs and systems. First we discuss a new 320 X 240, 46 micrometer pitch FPA, which when put into a system with a transmission of 74%, will provide a system NETD of < 26 mK (F/0.8, 60 Hz). This FPA has a power of < 250 mW (which includes on-chip 14 bit analog to digital conversion), and virtually no crosstalk from saturation. Second, we discuss the first ever 640 X 480 element uncooled IR camera. This camera, which is based on a 28 micrometer pitch microbolometer staring FPA, produces a system sensitivity of < 150 mK, (F/1, 30 Hz) and has a Minimum Resolvable Temperature Difference of < 0.4 degrees Celsius at the Nyquist frequency. Finally, we have developed a new lightweight thermal weapons sight (TWS). Our TWS, which weighs < 3 lbs. (with battery) and operates over the -37 degrees Celsius to +49 degrees Celsius temperature range, has demonstrated a boresight retention of < 0.2 mrad after 1000's of rounds were fired.
Lockheed Martin is developing the first ever 640 X 480 uncooled microbolometer camera. This camera, designated the LTC650, has a new 28 micrometers pitch 640 X 480 microbolometer focal plane array and electronics which operate at a 30 Hz frame rate. The electronics are based on previous successful 320 X 240 camera electronics which use low power, high performance DSP and FPGA technology. A DSP based software solution provides flexibility to answer the challenge of change and varied customer needs while meeting the low cost, low power, and low real estate requirements of portable, hand held applications. Test data for the first camera are presented.
Observations using the Starfire Optical Range (SOR) 1.5m telescope, located near Albuquerque, NM, were made during two separate observing runs, one in 1995 and the other in 1996. Image data was collected using a cooled 2K by 2K user provided CCD camera system. During the first observing sessions a standard SOR direct imaging configuration was used where a CCD imager. For the second observing run the configuration was modified to use a mirror with a small on- axis hole that allowed all the light in the central region to be used by the AO system while the remainder of the field was directed to the CCD. The data from these observations were used to investigate a number of issues related to AO observing including: (i) the effect of scattered laser light on image quality; (ii) the photometric accuracy across an AO corrected field; (iii) the PSF variations across an AO corrected field; (iv) the limits to observation of close companions using a mirror with a hole as a coronograph. The result of these observing runs are presented along with representative images obtained using no correction, partial correction, using natural guide stars, and Rayleigh laser beacon configuration.
A photon counting system, utilizing a CID as the imager sensor, is under development at RIT. The system integrates a programmable, DSP based driver system capable of generating fast readout and sub-array dynamic control sequences. A high speed event recognition and centroiding computation task is performed by a dedicated board, based on field programmable gate array technology, which provides the necessary spatial resolution while maintaining high data throughput capability. The system architecture is flexible and capable of handling different CID array architectures and sizes. Preliminary performance results are presented, and characteristics of CIDs, such as subarray injection, that impact the total possible throughput, and therefore, the dynamic range, are discussed.
Charge coupled devices have been the dominant solid state detector array in the visible due to their relatively simple design and easy implementation. With recent advances in lithographic techniques, arrays having smaller photosite dimensions and an increased number of pixels have become available. Further advances in large format CCDs have been limited by charge transfer efficiency (CTE) of photoelectrons to the readout amplifier. The increased number of pixel transfers in large arrays can degrade image quality and MTF unless even higher CTEs are achieved. Multiplexer designs that remove the need for thousands of charge transfers can bypass these CTE limitations. One such focal plane architecture is the CID or charge injection device. This paper presents results obtained with one particular CID based system. The array is housed in a dewar capable of liquid nitrogen operation. The output signal from the array is amplified with a nearby low noise preamplifier before digitization. Results on injection efficiency, readout noise, and other pertinent CID parameters, are presented obtained from this device preamplifier as well as specific experiments.
Turbulence is known to be the factor limiting resolution in long exposure images taken through the earth's atmosphere. The degradation is such that the images obtained can be described by the classical Seidel aberrations. Adaptive optics can be used to remove these aberrations to the maximum extent possible with corrective optics and a reference object. Full compensation systems are preferred, but are costly and complex. Significant improvement in image quality can be obtained by removing only the lowest order aberration, that is random tilts. These 'partial adaptive systems' have been used to produce high quality images in the visible and infrared. For most systems, determining the orientation of the incoming wavefront has required two separate imagers; one for determining wavefront variations and another for integration of photons in the field of interest. This has resulted in a need to split the incoming light with beamsplitters or choppers. In this paper, a new method of tracking tilts with only one focal plane array has been devised. Experiments with a Charge Injection Device (CID) used in conjunction with tip-tilt mirrors has been shown to be capable of first order motion correction. Limitations of this overall system as well as results and analysis from experiments will be presented.
Arrays of silicon sensors arranged in a CCD focal plane architecture have become the detector of choice for astronomical imaging in the 300 nm to 1 micron region. However other focal plane architectures offer attractive additional features such as allowing for random access to, and readout of, any subarray on the chip, and the nondestructive interrogation of the signal level of any pixel. A 512 x 512 pixel array utilizing a Charge Injection architecture that offers such advantages has been tested at liquid nitrogen temperature as to its suitability for use in astronomy. Laboratory tests show that using nondestructive readouts results in a (root)N (where N is the number of readouts) improvements in the noise figure (approximately 20 electrons rms noise after 100 reads). Initial images with a CID-38 of a number of astronomical objects are also presented.
A study has been made of some of the factors affecting the quality of the recorded image when using a large format 2K X 2K Kodak CCD imager. The optimal means for removing the dc offset, often referred to as the bias, is to sample many such frames and take a median at each pixel. The effects of external noise from electronics and cosmic rays are then removed well. The remaining noise in the frame appears to have a Gaussian form. The effect of pixels that accumulate signal due to a high thermal current can be significantly reduced by cooling. To remove the non-uniformity across the array due to the variation in responsivity from pixel to pixel it is extremely important to acquire images of uniform fields at the wavelength at which the observations of interest were made. This is especially important when image acquisition is over wavelength ranges outside the normal visual. For highly accurate photometric applications residual image effects needed to be considered.