EAGLE (Evolutionary Air & Space Global Laser Engagement) is the proposed high power weapon system with a high power laser source, a relay mirror constellation, and the necessary ground and communications links. The relay mirror itself will be a satellite composed of two optically-coupled telescopes/mirrors used to redirect laser energy from ground, air, or space based laser sources to distant points on the earth or space. The receiver telescope captures the incoming energy, relays it through an optical system that cleans up the beam, then a separate transmitter telescope/mirror redirects the laser energy at the desired target. Not only is it a key component in extending the range of DoD's current laser weapon systems, it also enables ancillary missions. Furthermore, if the vacuum of space is utilized, then the atmospheric effects on the laser beam propagation will be greatly attenuated. Finally, several critical technologies are being developed to make the EAGLE/Relay Mirror concept a reality, and the Relay Mirror Technology Development Program was set up to address them. This paper will discuss each critical technology, the current state of the work, and the future implications of this program.
Pointing the line-of-sight of an acquisition, tracking and pointing (ATP) system at a target requires designation of a reference line of sight (LOS) based principally on the target image. For many system, this will also include registration of a specific fiducial on the target for precision pointing. It is difficult to select a track reference because of algorithm sensitivity to modeling of the image. The selection of a track reference ins further complicated by image variations associated with changes in the viewing geometry and target characteristics. This paper compares several image-processing algorithms for the precision pointing of a near-space ATP platform that is viewing missile targets. The platform has state-of-the-art alignment, stabilization and tracking functions. The algorithms are tested in a full imaging and control system simulation that models an illuminating laser beam, target reflectance, optical effects, the sensor, a high order control system and pointing dynamics. The target models are based on flight dynamics, orientation, measured drawings and surface reflectivity. The simulation results are compared by calculating bias, drift and jitter characteristics of the error incurred when attempting to point the optical line-of- sight at the target. Several algorithms have been identified that provide a pointing reference capable of sustaining sub- microradian error. This paper describes the calculation of the fiducials for the algorithms and compares their relative merits.
Successful tracking of a target from the High Altitude Balloon Experiment (HABE) requires selecting an initial position for the HABE platform so the greatest quantity and quality of imagery can be gathered for the longest duration. During the engagement period, a target typically covers a large distance while HABE drifts with the wind. The parameters of the engagement used to measure potential success depend directly on the capabilities of the tracking hardware and software. An engagement analysis technique has been developed which allows optimization of important engagement parameters. This technique can support a wide variety of tracking platforms which require pointing to specific locations or targets. Two methodologies are described in this paper which predict those positions for HABE where the most desirable engagements will be achieved against a nominal target. The desired objective is a long period of continuous maintainable track.