High Energy Laser weapons (HEL) have unique attributes which distinguish them from limitations of kinetic energy
weapons. HEL weapons engagement process typical starts with identifying the target and selecting the aim point on the
target through a high magnification telescope. One scenario for such a HEL system is the countermeasure against
rockets, artillery or mortar (RAM) objects to protect ships, camps or other infrastructure from terrorist attacks.
For target identification and especially to resolve the aim point it is significant to ensure high resolution imaging of
RAM objects. During the whole ballistic flight phase the knowledge about the expectable imaging quality is important to
estimate and evaluate the countermeasure system performance. Hereby image quality is mainly influenced by
unavoidable atmospheric turbulence.
Analytical calculations have been taken to analyze and evaluate image quality parameters during an approaching RAM
object. In general, Kolmogorov turbulence theory was implemented to determine atmospheric coherence length and
isoplanatic angle. The image acquisition is distinguishing between long and short exposure times to characterize tip/tilt
image shift and the impact of high order turbulence fluctuations. Two different observer positions are considered to show
the influence of the selected sensor site. Furthermore two different turbulence strengths are investigated to point out the
effect of climate or weather condition.
It is well known that atmospheric turbulence degenerates image sharpness and creates blurred images. Investigations are
done to estimate the effectiveness of simple tip/tilt systems or low order adaptive optics for laser based C-RAM systems.
The realization of a high-energy laser weapon system by coupling a large number of industrial high-power fiber lasers is investigated. To perform the combination of the individual beams of the different fiber lasers within the optical path of the laser weapon, a special optical set-up is used. Each optical component is realized either as reflective component oras refractive optics. Both possibilities were investigated by simulations and experiments. From the results, the general aspects for the layout of the beam-guidance optics for a high-power fiber laser system are derived.
At MBDA Germany a concept for a high-energy laser weapon system is investigated, which is based on existing
industrial laser sources. Due to the enormous progress in the field of high-power fiber lasers, commercial industrial
fiber lasers are now available delivering a nearly-diffraction limited beam quality with power levels of up to 10 kW. By
using a geometric beam coupling scheme, a number of individual high-power fiber laser beams are combined together
using one common beam director telescope. A total laser beam power of more than 100 kW can be achieved, which is
sufficient for an operational laser weapon system.
The individual beams from the different lasers are steered by servo-loops using fast tip-tilt mirrors. This principle
enables the concentration of the total laser beam power at one common focal point on a distant target, also allowing
fine tracking of target movements and first-order compensation of turbulence effects on laser beam propagation. The
proposed beam combination concept was demonstrated by using different experimental set-ups. A number of
experiments were performed successfully to investigate laser beam target interaction and target fine tracking, also at
large distances and at moving targets. Content and results of these investigations are reported, which demonstrate the
complete engagement sequence for a C-RAM scenario. This includes subsequent steps of target acquisition by radar
and IR optics, followed by large angle coarse tracking, active fine tracking and destruction of the target by the laser
system. This successful implementation of geometric beam combining is an important step for the realization of a laser
weapon system in the near future.
Due to the enormous progress in the field of high-power fiber lasers during the last years commercial industrial fiber
lasers are now available, which deliver a near-diffraction limited beam with power levels up to10kW. For the realization
of a future laser weapon system, which can be used for Counter-RAM or similar air defence applications, a laser source
with a beam power at the level of 100kW or more is required. At MBDA Germany the concept for a high-energy laser
weapon system is investigated, which is based on such existing industrial laser sources as mentioned before. A number of individual high-power fiber laser beams are combined together, using one common beam director telescope. By this ‛geometric‛ beam coupling scheme, sufficient laser beam power for an operational laser weapon system can be achieved. The individual beams from the different lasers are steered by servo-loops, using fast tip-tilt mirrors. This principle enables the concentration of the total laser beam power at the common focal point on a distant target, also allowing fine tracking of target movements and first order compensation of turbulence effects on laser beam propagation. The proposed beam combination concept was demonstrated using several experimental set-ups. Different experiments were performed, to investigate laser beam target interaction and target fine tracking also at large distances. Content and results of these investigations are reported. An example for the lay-out of an Air Defence High Energy Laser Weapon (ADHELW ) is given. It can be concluded, that geometric high-power beam combining is an important step for the realization of a laser weapon system in the near future.
We propose a method for 3D-structure extraction from the image data of a flying platform equipped with an IR-camera.
Due to the large distance of the camera to the target, trajectories with limited perspective variation and low resolution
cameras the task is challenging. Our method is based on the extraction and tracking of line segments together with
junction points of line segments. These tracks are afterwards used for 3D-reconstruction. In a second step knowledge
about typical properties of man made objects is incorporated in the reconstruction results to generate intrinsically