EUREKA PROJECT > 3714 INGAAS GATED IMAGING
ISRAEL
INGAAS GATED IMAGING SYSTEM IGC
AN EYE SAFE GATED IMAGING SYSTEM WITH OUTSTANDING PERFORMANCE. BASED ON A NOVEL INGAAS FOCAL PLAIN ARRAY (FPA) SYNCHRONISED TO AN EYE SAFE GATED LASER. BRINGING THE BEST IMAGE IN ALL WEATHER WITHOUT JEOPARDISING IMAGED HUMANS.
Status > FINISHED - 07-Dec-2011 Technological Area Market Area Start Date > 01-Nov-2006 Duration > 24 Months Participating countries > ISRAEL, BELGIUM | Main contactELBIT SYSTEMS LTD Mr. Schneider Ron > Organisation type > Large company |
Project Description
In several fields there is a growing interest in imaging at long ranges and imaging without jeopardizing people in the field of view. The requirement for long range observation and eye safety requires operations within a wavelength of 1.5um, which is considered eye safe. In this project we aim to develop an outstanding eye safe gated imaging system. This will provide clear images in all weather and for long ranges. Such a system is composed mainly of four building blocks: a laser, gated camera, control electronics and optics. The main technological gap is in the camera. The project aim is to design, manufacture and test a camera to be used in the laser gated schema. The camera is to detect laser pulses at a wavelength of 1.5um. Today, ELBIT SYSTEM is a world leader in gated imaging at 800nm. The cameras used today are based on an Image intensifier which has a limited sensitivity up to 850nm. The 850nm limit causes the current systems to be non-eye safe, apparent to the naked eye and to other commonly available viewing devices. The eye safety issue holds far more importance. The maximum permissible energy (MPE) allowed at 1.5 um is much higher than at 800nm. Thus, if the system is to be eye safe and covert to such sensors, the 1.5um region needs to be looked at. The combination of XENICS with expertise in the detector array and readout, will combine with ELBIT's expertise in gated imaging and system design. XENICS will design and manufacture the sensor chip which includes the INGAAS detector array and the readout Si that is bound to it. ELBIT will design the camera which is based on the developed sensor chip. The camera will be integrated into a 1.5um gated imaging system. The gated imaging system uses a pulsed laser with synchronisation to the camera. In such a way, the contrast degradation due to backscattering associated with active illumination systems is avoided. The resolution is usually regarded as proportional to the wavelength, so we can expect degradation in performance compared to the 800nm. However, this is not the case in the low light level since the effective pixel is larger than the diffraction limit. As for competitors, there are similar systems but none are using our gating scheme. Most of the INGAAS cameras are used with a single shutter during one integration time as opposed to the method we are offering where multi gating pulses are exposed during one integration time. We call this method ‘multiple gates in a frame’ (MGF). With this method, we perform multiple exposure in a single frame. Within the frame time, all charges received during a gate ‘on’ are accumulated and all the charges accumulated in the photo diode during gate ‘off’ are drained to the ground (disposed). Once enough charges are accumulated in the storage site in the pixel, a readout process will be executed. The sensitivity of an imaging device is limited due to noise. The most significant noise sources are – dark current, readout, KTC and shot noise. Shot noise is reduced with the increase of charges. Dark current shot noise charges will increase with integration time but can be reduced if the chip is cooled. Read out noise is constant and usually the most dominant one. If we can accumulate the amount of charges in order to overcome these noise sources and achieve a signal to noise grater then 3 to 5, the image quality should be sufficient. A detailed analysis of noise, laser power and system constraints should be performed at the initial stage of the project. This initial analysis will result in a detailed specification for the sensor chip laser and system design. Keywords: eye safe, laser imaging, camera.
Technological Development Envisaged
The outcome of the current programme will be an eye safe gated imaging system for long and short ranges with no blooming from close objects and penetrating the atmosphere more efficiently. By using the gated imaging scheme, the system eliminates the backscatter from the aerosols and dust particles in the atmosphere. The outcome can be divided into the following: - INGAAS Focal Plain Area (FPA). - INGAAS Camera. - Gated Eye Safe Laser. - Control electronics for the Laser and Camera. - Gated Eye Safe Imaging system. In the INGAAS FPA, we will develop a unique readout that enables gating at the appropriate gate width and repetition rates. In the INGAAS camera we will develop the logic electronics to control the readout circuitry. The Gated Eye safe laser task is to gate an existing eye safe cw (Coarse Wavelength) laser.
Main contactELBIT SYSTEMS LTD Mr. Schneider Ron > Organisation type > Large company |
Contribution to project
The organisation is a leading defence industry with worldwide manufacturing facilities. As part of its strategy, ELBIT also works on commercial applications. As an example, a line of sight cuing system developed for aviation pilots was applied to the medical industry. We are developing night vision for the automotive industry under a contract for OEM (Original Equipment Manufacturer) manufacturers. ELBIT's experience in the field of long range observation will contribute to the project as follows: - System requirements * Laser * INGAAS sensor * Optics * Image processing - System architecture - The gating scheme - The Optical design - The INGAAS camera design and manufacturing. - System integration as a stand alone - System integration on several platforms * Air * Sea * Ground. ELBIT has experience in active gated imaging in 810 nm. In addition ELBIT is the initiator of the project. In this project, ELBIT will develop the camera, while the sensing FPA and readout will be carried out by XENICS.
Expertise
The organisation’s experience in the field of active gated imagery is based on more then 10 years of developing such systems. We have developed long range active systems. Another field of gated imaging is short range, e.g. automotive night vision which was delivered to GM. We are developing an 810 nm based system in cooperation with CRF (FIAT RESEARCH CENTRE) in ITALY. ELBIT has the knowledge in optics radiometry to facilitate the system. We are a manufacturer of lasers and optical systems. We own several patents in the field of active gated imaging and are at the leading edge of technology worldwide.
Main contactXENICS N.V. MR. JAN VERMEIREN > VICE PRESIDENT / R & D MANAGER Organisation type > SME |
Contribution to project
The organisation is a worldwide manufacturer of infrared detectors for infrared spectroscopy, non-contact temperature measurement, smart sensors and thermal imaging systems. XENICS' infrared detectors are based on state-of-the-art INGAAS compound semiconductors and on SiGe microbolometer technology and cover the wavelength range of 1 to 14 micrometers. At this moment XENICS produces a large variety of image sensors and cameras: * Linear INGAAS sensors and cameras with 128, 256 and 512 pixels for spectroscopic and imaging applications, * INGAAS FPAs and cameras with 320*256 and 640*512 pixels; present versions include general purpose and low noise, low light level imaging devices; High frame rate devices are currently under design. * InSb cameras for thermography, * Microbolometer cameras for thermal imaging and thermography. In this project, XENICS will develop and manufacture: + the INGAAS FPA attached to the Si read out, + the high speed Si readout circuit + the initial test electronics.
Expertise
The organisation designs, manufactures and sells infrared detectors covering the infrared wavelength range of 1 up to 14 micrometers. Our infrared detectors come as single element detectors, linear or two-dimensional detector arrays. XENICS also delivers custom detectors according to agreed specifications and planning. It is our mission to be a reliable partner in the supply of infrared detectors for our customer's wide range of applications. Standard and extended wavelength 2D INGAAS detector arrays operate in the wavelength range of 0.9 to 1.7 or 2.5 microns. The INGAAS series of two-dimensional arrays of photodiodes is specifically suited to near infrared (NIR) imaging applications. The image sensor is a hybrid assembly of a focal plane array of INGAAS photodiode flip-chips bonded to a readout circuit. The sensors come in hermetically sealed packages with anti-reflection coated windows. XENICS offers standard OEM products as well as custom designs for infrared imaging devices.