MBDA UK Ltd (Precision Solutions)

The use of mmW RF imaging technology (94 GHz) provides a powerful solution to landing in all visibility conditions, including white-out and brown-out. It has significant benefits over IR imaging methods in the range of conditions it can accommodate, and the detail with which obscured objects can be imaged.

MBDA has been a leading exponent of mmW RF seeker technology for over 20 years and is the first defence company in the world to exploit the technology in volume production. As a result of this experience, especially on the Brimstone RF seeker development, derivatives of the seeker technology with defence, security and commercial applications can be offered.

> An imaging radar sensor to enable pilots to land in zero height, zero visibility conditions
> Alternative applications of the same core radar unit for military, quasi-military and commercial deployments
> A landing aid for helicopter pilots to enable landing in helicopter induced dust or sand clouds (brown-out) or snow (white-out)
> A rapid throughput personnel security scanning device

None of these require significant changes to the sensor architecture. In each case an application specific antenna, software and interfaces are all that is required.

MBDA’s exceptional experience in RF, IR, laser and associated technologies used in the development and application of seeker technology for missile systems can be applied to other sensor and imaging applications. Particular applications include helicopter and aircraft landing in low visibility conditions.

A specialist team provides a wealth of experience and knowledge in the design and production of electro-optical components, modules and systems for a variety of defence and commercial applications. Concept and feasibility studies can be undertaken prior to the manufacture of prototypes and full scale volume production. Design tools include CODE V, ZEMAX, AUTOCAD, PRO-ENGINEER and specialised in-house software.

The unique blend of design, development, manufacture, assembly and test facilities for optical components and assemblies allows us to to offer a design and development capability for:

> Industrial components & subsystems
> Miltary components & subsystems

Industrial optical component designs have included lenses for surveillance, telecentric and telemetry systems as well as aspheric, diffractive and Fresnel lenses. Metal mirrors with parabolic, off-axis and elliptical surfaces have been designed and manufactured . Mould tools can also be produced for optical components such as Fresnel lenses, contact lenses and lens arrays.

Military applications have included optics for both cooled and uncooled sensors, as well as optics for lasers, seekers and missile systems.

We can also offer a consultancy service for all aspects of optical design & development to both industry and academia.

INTERFIRE II interferometers are available in unique dual waveband configurations, featuring two lasers feeding a single base-unit. With an alignment laser operating at 633 nm also built into the same enclosure, set up is quick and easy. Once set up, measurements can be made without the need to re-align the test piece. The most popular configuration features a LWIR laser operating at 10.6 µm and a MWIR laser operating at 3.39 µm, although lasers operating at other wavelengths are also available.

Key benefits of the dual waveband system include:
> Ease of set up
> Space saving − all lasers feed a single unit
> Cost savings − dual waveband system less expensive that two independent systems
> Dynamic range extension
> Comprehensive range of accessories and software

These rugged, easy-to-use instruments can be used for development, test, production, quality control or research applications and are fully supported with a comprehensive range of optical and mechanical accessories and static and phase- measuring fringe analysis software options for the accurate measurement of wavefront aberration of thermal imaging lenses, optical homogeneity of infra red materials and flatness of optical surfaces.

The reflective beam expander accessory is designed for the analysis of large optics using the INTERFIRE range of infrared interferometers and can be used in the 3-5 micron and 8-12 micron wavebands. The unit is produced in collaboration with Optical Surfaces Ltd and features a Newtonian configuration not a Galilean configuration to provide an intermediate focused image for efficient relaying of optical pupils,which is essential at longer infrared wavelengths.

The reflective beam expander is a robust, standalone unit which can be bolted to an optical bench with height adjustment for fine alignment. It contains a matched pair of permanently aligned aluminium mirrors, complete with magnesium fluoride protective coatings.

It has a wavefront accuracy of lambda/10 in the 3-5 micron waveband, with output apertures of 150 mm and 200 mm as standard, although other sizes are available. The input aperture of 30 mm is matched to the INTERFIRE output aperture.

Optical accessories available for use with the INTERFIRE range of interferometers include:
> Phase shifting accessory
> Static fringe analysis software
> Reflective beam expander
> Refractive collimator to give 100mm aperture
> Beam expander 150mm
> Beam expander 200mm
> Beam expander 300mm
> Transmission sphere f/1
> Transmission sphere f/2
> Transmission sphere f/4
> Transmission sphere f/8
> Compact precision mount 2 axis (tilt) including element holder
> Compact precision mount 5 axis (tilt + xyz) including element holder
> Large precision mount 2 axis (tilt) incl. element holder
> Large precision mount 3 axis (tilt) incl. element holder
> Large precision mount 5 axis (tilt xyz) incl. element holder

Phase shift software
The phase shift software is extremely versatile and allows information to be obtained from different parts of the optical surface under test. These display formats can be extended to all measured data, such as aberration fields, MTF and slope field. Results can be displayed directly in terms of ISO and DIN standards. Phase measuring interferometry is a more accurate technique than static fringe analysis since it offers higher density and uniform sampling of the interference pattern, and better phase resolution.

> Piezo mirror control
> Phase shifting control
> Vision Fringe acquisition and interpretation software
> Frame grabber PC card
> PC DAC card

For more information, visit the Fisba website

Static Fringe Analysis
A variety of static fringe analysis software packages is available. Static fringe analysis typically offers an accuracy of around lambda/20 and has the benefit that the software results can be verified manually for simple peak to valley measurements.

Software offers far more sophisticated analysis including calculation of the rms wavefront deviation, and other derived functions such as the StrehlRatio, MTF, Point Spread Function and Encircled Energy Function. The wavefront shape is often approximated by fitting Zernike coefficients to the available data, enabling the calculation of Seidel Aberrations.The software can also flag pass/fail criteria based on irregularity, power, peak to valley wavefront value and rms wavefront aberration.

The INTERFIRE II family of infra-red interferometers is available with a choice of lasers operating at 10.6 microns wavelength, in the 3-5 micron wavelength range, at 1.55 microns or 850 nanometres and allows fringes to be obtained quickly and easily with excellent signal-to-noise.

The INTERFIRE II series of infrared interferometers can be used in development, test or production laboratories and is used for the accurate measurement of wavefront aberration of thermal imaging lenses, optical homogeneity of infra red materials and flatness of optical surfaces.

The construction of the INTERFIRE II, combined with a fast warm-up time means that fringe images can be quickly and easily produced with no focus drift. All instruments feature a focal plane array camera which is much more sensitive than previous cameras and has significantly reduced noise, allowing high quality images of fringes to be acquired quickly, easily and with no focus drift. When used with phase shifting fringe analysis software, the acquisition of fringes is much more reliable. The phase shifting technique used allows the highest degree of precision and enables full use of standard accessories.

The Imaging Infrared Countermeasures facility has been designed with expansion in-built for future trends in seeker technology. Active laser systems operating as LADAR seekers are under development and need new approaches to simulation and HWIL.

MBDA has been developing methodologies for LADAR testing in a HWIL environment and are able to offer designs to expand the current capabilities of HWIL test benches to include LADAR testing through the provision of the third dimension of range and target depth.

RF technologies are available for use in non-missile systems such as frequency synthesiser subsystems, microwave receivers, transmitters as well as radar imagers for use in civil or defence radars. MBDA is particularly skilled in the art of microwave component and subsystem design.

Aerodynamics, propulsion and lethality provides unparalleled expertise in aerodynamics and airframe design, computational fluid dynamics and propulsion.

> Define and redefine aerodynamic configuration
> Definition of aerodynamic characteristics
> Aerodynamic loading distribution for airframe design
> Numerical simulations of complex fluid flow
> Aerodynamic loading data for stress analysis
> Definition of propulsion requirements
> Assessment of proposed propulsion system

Engineering a realistic environment is one of the most challenging tasks in an environmental engineering laboratory. The Environmental Engineering test facility provides simulation and testing capabilities for a wide range of environmental conditions to aid design and formal qualification.

In particular, it is possible to create a number of different environmental test conditions simultaneously to simulate a real world environment.

MBDA’s facility for imaging infrared seeker assessment is at the leading edge of real-time hardware-in-the-loop test capabilities. It provides a laboratory test aid to examine seeker behaviour in the presence of complex background, targets and high temperature countermeasures, offering a highly flexible and versatile architecture for sensor, seeker and algorithm testing.

A modular VHF test source has been developed by MBDA UK Ltd in order to address EMC requirements for both military and non-military RF susceptibility and effects testing. This high power microwave test source comprises four subsystems: a Remote Control Unit (RCU), a Power and Control Unit (PCU), a Support Unit (SU), and a Radiating Unit (RU). The system is capable of operating from single shot up to high PRFs in either burst or continuous mode, and runs from a 24VDC power supply.

> Operating frequency: 80MHz to 200MHz
> 1 million pulse lifetime
> Field levels representative of DEW sources in the far field
> Variable Pulse repetition frequency:
> Standard up to 20Hz continuous
> Available with greater than 1kHz in bursts
> High reliability: no regular maintenance required
> Built in Safety Monitoring system

The high power microwave test source development programme has resulted in a very significant improvement to the longevity of the RF test source. A number of issues have been resolved by the use of novel techniques. These include new high voltage insulation techniques, new approaches to high voltage switch design and the reduction of high electric field stresses through the use of novel materials.