BAE SYSTEMS2003-10-29 08:58:54


BAE SYSTEMS is leading a combined industry and academic team in the development of the next generation of air speed sensors. The Laser Air Speed Sensor Instrument (LASSI) programme is being undertaken by BAE SYSTEMS Advanced Technology Centre (ATC) in collaboration with Advanced Optical Technology Ltd., Spectrum Technologies and the Department of Physics at Hull University. The programme, sponsored by the UK Department of Trade & industry (DTI), will see the development of an air speed sensor using an ultra-violet laser designed to increase accuracy of airspeed measurement over a much wider range of speeds than traditional methods.

The current method for measuring air speed uses the pitot tube ) a cylindrical tube attached to the aircraft that points into the airflow. A device attached to the base of the tube measures the forward air pressure and the air pressure at right angles to the direction of motion or static air pressure. The difference in pressures is used to calculate the velocity of the aircraft. Whilst accurate at high speeds, the ability of the pitot tube to resolve the differences in forward and static pressure at low speeds is very limited. This makes the measurement of airspeed at low velocities extremely difficult and is a serious problem for helicopters, particularly during low speed manoeuvres close to the ground. Additionally, on fixed-wing aircraft, the pitot tube increases the drag on an aircraft and hence fuel consumption.

Under the DTI programme, the team will develop a laser based sensor system and construct a portable system demonstrator. The development activity will include amongst the overall concept, the research and design of a compact, short pulse laser and a fibre optic system. By firing the laser into the atmosphere, the nature of the light reflected from the air molecules will change with speed. This variation is measured by the LASSI system and converted to airspeed.

The LASSI programme will see the creation of a non-intrusive, all altitude, high accuracy measurement sensor for use at high and low speeds which will provide significant benefits for all forms of aircraft. For helicopters, LASSI will greatly improve the information provided to pilots during low speed activities potentially increasing safety. For fixed-wing passenger and transport aircraft, the reduction in drag achieved with the removal of pitot tubes will see savings in fuel over long journeys. The ability to +steer, the sensor will enable accurate vector measurements to be taken improving the control of flight. For military aircraft, LASSI will enable a reduction in the radar cross section of the aircraft and hence improve its survivability in enemy territory. LASSI could also be used for alternative applications such as mapping the airflow around buildings and structures.

BAE SYSTEMS Advanced Technology Centre (ATC) provides innovation, expertise and services for the creation and development of future technology capability. From hardware to software development, composite materials to stealth techniques, sensing systems to synthetic environments, the ATC provides innovative solutions to customer requirements. With a highly skilled, world class scientific workforce, the ATC provides services, capability and support throughout the product lifecycle, from long term speculative research to in-service product development. Key skills and expertise are available to provide assistance for short-term product development and mid-term next generation programmes.

About Advanced Optical Technology Limited:
Advanced Optical Technology (AOT), was set-up in 1999 to undertake customer contracted R&D projects in photonics and to develop new solutions based on DPSSLs for key market applications.
Current products comprise the ACE range of E-O Q-switched DPSSL sources, unique in offering TEMoo pulses of ~ 1ns duration and operation to = 50kHz repetition-rate.
The sources are intended for a wide range of applications from high precision micromachining to R&D. The ability to synchronise the pulses with very low jitter to external events means that the lasers have wide appeal for scientific and instrumentation applications. The company strategy includes the development of strong collaborative links with partners offering complimentary technology and market skills, and with key and influential users in target application areas i.e. selected R&D and commercial organisations involved with photonics-based solutions.
The company has a strong commitment to product development, and to maintaining a high level of product enhancement and new product launches, seeing these as essential for sustaining on-going commercial success. As a result, AOT is a recognised innovator in the laser field. Most recently, the Royal Commission for the Exhibition of 1851 has awarded one of the company,s staff a prestigious Industrial Fellowship, allowing the holder to pursue focussed research for the tenure of the award.

About Hull University, Department of Physics:
Research within the Laser Group at Hull centres on the interaction of pulsed infrared, ultraviolet and vacuum ultraviolet lasers with materials, with the objective of understanding basic mechanisms in ablation and photo-modification and developing new materials processing techniques. The group has made significant contributions in the fields of UV and IR laser ablation of organic polymer and bio-polymers, pulsed laser deposition for thin film growth, fibre Bragg grating fabrication using UV and VUV excimer lasers and, most recently, 157nm laser micromachining of glasses. An important aspect of this work has been the development of diagnostic probes (e.g. photo-thermal deflection, photo-acoustic, fast photographic) and the exploitation of analytical techniques such as optical-, scanning-electron- and atomic-force-microscopy for characterising ablation. This research has been supported by the EPSRC and the EU and has benefited from close collaboration with industry. The group has published extensively on these topics and, to date, the applicant (PED) has 175 papers relating to laser devices, optical resonators, ablation and laser micromachining and materials modification.

About Spectrum Technologies:
Established in 1989, Spectrum Technologies is a world leader in the design and manufacture of specialised state-of-the-art industrial laser systems. Spectrum,s flagship product is CAPRIS, a family of ultraviolet (UV) laser wire marking and processing systems, developed principally for the international aerospace market, for use in the manufacture and maintenance of complex aircraft electrical systems. The Company has almost every major aerospace manufacturer on its customer list. Spectrum is aiming at further growth and diversification after expanding its activities in 2001 through the acquisition of its main competitor, Vektronics Inc of Vista, USA, and also RtMc Inc of Phoenix, USA, which manufactures a range of complementary infrared laser wire stripping products, which are offered primarily to the medical and other non-aerospace industries including the IT and telecommunications, consumer electronics, and computer industries. The Company won three export awards in 2000, including the Queen,s Award for Enterprise for International Trade. Spectrum is 20% owned by BAE SYSTEMS.

For more information contact:
Warwick House
Po Box 87
Farnborough Aerospace Centre
GU14 6YU
United Kingdom
Tel:     + 44 1252 373232
Fax:     + 44 1252 383000



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