We present a novel device for fast, reproducible and low contrast minimum resolvable contrast (MRC) measurements
based on an OLED microdisplay. The high intensity resolution and luminosity of the employed display allows the
generation of target contrasts well below 0.5 % at brightness levels of more than 500 nits. Using a 4 m collimator we
were able to perform an MRC measurement over the full relevant spatial frequency range of a recently developed
terrestrial TV camera system. The small pixel pitch of the display allowed us to use a short collimator length and to
perform MRC measurements with high frequency resolution.
The European anti-tank missile system MILAN has found wide-spread use in numerous countries. Introduced in 1974 it has since undergone several technological upgrades. We report here on the newly developed firing post MILAN ADT ("Advanced Technology") which improves the MILAN system performance substantially while maintaining all operational features to which MILAN operators are accustomed. An even further advanced version of this firing post is now under development in the frame of a range extension of the missile system dubbed MILAN ADT/ER. Being a command-to-line-of-sight system, the new MILAN ADT firing post is equipped with a missile tracking sensor which captures the missile's signature with a wide field-of-view optics and a large CMOS detector covering both gathering and guidance phase. Using adaptive windowing and sub-sampling functions combined with differential imaging modes this sensor tracks the signatures of all MILAN missile types with optimum precision, high resistance against IRCM, and improved signal-to-noise ratio over the entire flight path. An integrated thermal imager replaces the earlier ancillary TIs, MIRA and MILIS. The TI image is displayed on an internal micromonitor and projected into the eyepiece. Optimum axis harmonization between both missile tracking and sighting channels is ensured by projection of reference marks into each optical sensor path from an integrated multispectral projector. An extended range version will also be offered which takes advantage of the missile tracking sensor's enhanced responsivity and the oustanding precision of axis alignment. An integrated color TV sensor is substituted for the bulky direct view telescope, and both TI-/TV-sensor will provide two fields-of-view on the internal micromonitor for surveillance and target identification, respectively.
When the field of operation of precision strike ground/air-to-ground missiles is extended to beyond-line-of-sight missions, autonomous seekers will soon encounter serious difficulties, especially with regard to low signature targets and complex scenarios. We have investigated dual-mode sensors which are conceived to overcome these specific problems by combining an imaging sensor with a semi-active laser seeker. These sensors offer non-line-of-sight target engagement with high reliability and under operator control using a laser target designator while minimizing the active exposure time for target designation by handing over the tracking process, once the passive imaging sensor has locked onto the target. For this purpose a laboratory demonstrator has been built with a standard TV-sensor and an InGaAs 4-quadrant detector mounted on a 2-axes gimbal system. Both detectors use a common objective; the focussed radiation is divided by a spectral beam splitter. The signals of the 4-quadrant detector are digitized and subsequently processed by an FPGA. If the pre-programmed laser pulse characteristic is identified, the position information is evaluated and the gimbal system activated in order to center the laser spot. Subsequently a tracker locks onto the target signature found in the imaging sensor signal. Once lock-on is confirmed the laser can be turned off automatically. We present the results of laboratory and field tests obtained with the dual-mode demonstrator. Based on these results we plan to replace the TV-sensor by an uncooled microbolometer array in the future. The design and expected performance of such a dual-mode sensor will be discussed.
Keywords: dual-mode sensor, semi-active laser seeker, microbolometer array, target engagement
A new firing post MILAN ADT ("Advanced Technology") is developed by EADS-Lenkflugkoerpersysteme GmbH with the aim to improve the performance of the MILAN weapon system substantially while maintaining all operational features to which MILAN operators are accustomed. The missile tracking sensor of MILAN ADT is now equipped with a single, wide field-of-view optics and a large CMOS detector covering both gathering and guidance phase. Using adaptive windowing and sub-sampling functions of the detector combined with differential imaging modes, all types of MILAN missile are localized with optimum precision over the entire flight path. Another novel feature is the integration of a thermal imager into the optical scheme of the MILAN ADT guidance unit. This replaces the earlier ancillary TIs MIRA and MILIS thus saving the weight of the additional housing and reducing logistic effort. The TI image is displayed on an internal micro-monitor and projected into the eyepiece of the daysight. Optimum boresight harmonization between both missile tracking and sighting channels is ensured by projection of reference marks into each optical sensor path from a common multispectral projector. MILAN ADT is compatible with all existing MILAN missile versions and with MIRA and MILIS TIs; the integrated TI is offered as an option. A planned future range increase of the MILAN weapon system will also be discussed in brief.
Based on the development of an IR seeker in 1992 and its extensive captive flight testing, the seeker of the trilateral (Germany, France, Italy) Polyphem missile was developed and tested in captive and free flights. It is based on a 640 X 486 element FPA and a cardanic stabilization and pointing system with an on-gimbal rate gyro. The digitized output of the FPA is sent to the ground via an optical fiber where it is observed by the operator and processed for cueing of targets and tracking for the final approach. After general seeker design considerations its design and performance and an in- flight video of a live firing will be presented. On the basis of the prior development of an IR seeker module set consisting of a 256 X 256 element InSb FPA and its electronics, the seeker for the German KEPD350 missile has been in development since 1997. Recently it has been qualified successfully and 25 of it will be delivered in 2001. Its mechanics consist of a miniaturized cardanic system which uses the data of the missile's Inertial Measurement Unit (IMU) for strap-down pointing and stabilization. Its image processor is designed for navigation during cruise and for tracking of the target in final approach. The seeker's features and performance will be presented.