Selected to meet the stringent requirements of the Gripen swing-role combat aircraft, the Cobra Helmet Mounted Display
System, has been integrated as a key component to the Gripen weapon delivery system. Saab Aerosystems has since
2003 together with BAE System been developing the Cobra HMD and in parallel integrating the system in Gripen for
South Africa. Work is currently done to prepare other customer for the Cobra HMDS. This paper will highlight some
technical challenges and experiences with integrating a HMDS in a small cockpit environment as in Gripen and present
an overview of the Cobra HMD design and installation. Furthermore the paper will discuss the importance of having the
pilots and users involved during the design phase and throughout the development.
The development of data generating sensors and computers in a modern fixed wing aircraft is not met by an increase in sensorial performance by the operator to assimilate this data. No new sensor has been developed nor has any drastic increase in data perception been implemented in the human operator since the first manned flight by the Wright brothers. Consequently we have to refine the media and the way in which we present data to the pilot. This document describes a platform for test and evaluation of head mounted technology and some new technologies that can be used for decreasing the pilot's workload. Furthermore, the document describes initial tests done on image quality and design of reflective coatings on visors.
Although the realisation of femtosecond X-ray free electron laser (FEL) X-ray pulses is still some time away, X-ray diffraction experiments within the sub-picosecond domain are already being performed using both synchrotron and laser- plasma based X-ray sources. Within this paper we summarise the current status of some of these experiments which, to date, have mainly concentrated on observing non-thermal melt and coherent phonons in laser-irradiated semiconductors. Furthermore, with the advent of FEL sources, X-ray pulse lengths may soon be sufficiently short that the finite response time of monochromators may themselves place fundamental limits on achievable temporal resolution. A brief review of time-dependent X-ray diffraction relevant to such effects is presented.
Time-dependent x-ray diffraction has been measured from laser-irradiated semiconductor crystals. Laser pulses with 100 fs duration and 800 nm wavelength excite the sample inducing phase transitions. 5 keV x-rays from the Advanced Light Source are diffracted by a sagittally-focusing Si (111) crystal and then by the sample crystal, InSb (111), onto an avalanche photodiode. By detecting individual pulses of synchrotron radiation, which have a duration of 70 ps, the diffracted intensity is observed to decrease because of photoabsorption in a disordered surfaced layer. Rocking curves measured after the laser irradiation show a tail, which results from a strained region caused by expansion of the crystal lattice.