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This Defense Intelligence Reference Document was prepared by the Defense Intelligence Agency's Defense Warning Office and dated 31 March 2010. It was produced under the Advanced Aerospace Weapon System Applications Program. It reviews chemical, solid-state, fiber, ultra-short pulse and free-electron lasers, as well as beam control, atmospheric propagation, DoD laser history and how spacecraft could be damaged by lasers. It projects that electrically powered lasers could enable MW-class weapons and spacecraft laser weapons within 20 years. It ends with shielding recommendations for spacecraft.
From the source:Release of 2026-09-18 Incident: 3/31/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD surveys the development of high-energy laser weapons and notes that, although lasers had already become important military tools for ranging, guidance, and other lower-power uses, true weapon-class systems remained limited by power generation, beam control, atmospheric propagation, and logistics. The report reviews major laser types along with the optical, tracking, and thermal-management systems needed to make them militarily useful. It argues that high-energy lasers can offer important advantages over kinetic weapons in speed, precision, and low collateral damage, especially against softer or fast-moving targets, while also emphasizing that practical deployment has long been hindered by hazardous chemical fuels, thermal blooming in the atmosphere, power-supply constraints for mobile systems, and waste-heat removal.
UNCLASSIFIED/ fFOA. OFFICIAL WSE er•tv completely in the vacuum of space, there is obviously no need for target loop adaptive optics. The measure of a beam control system's performance is its ability to maximize the HEL beam's average irradiance (watts/cm 2 ) in the focused spot on the aim point and maintain it there while sufficient fluence (watts/cm 2 x time or joules/cm 2) is accumulated. The total power in this focused spot is typically about one-half of the laser's output power further reduced by losses in the beam control system's optical train and the atmosphere. The laser beam's spot size on the target has many contributors. Optical diffraction establishes the spot's minimum area at approximately (RA/D)2 where R is the range to the target, 'A, is the laser beam's wavelength and D is the diameter of the pointing telescope. Improvement can be only achieved by reducing the range to the target, using a laser with shorter wavelength or increasing the pointing telescope's size. This ideal (diffraction limited) spot area, is unachievable in a real system. Additional contributors to the actual spot area include a less-than-perfect laser beam (beam quality greater than one), mechanical jitter of the beam control system from the tracker, the alignment systems, or base motion disturbance and atmospheric distortions from turbulence or thermal blooming. Each of these contributors to the laser beam spot's area serve to reduce the irradiance by spreading the laser power over a larger area. Figure 10 is a cartoon of the gimbaled portion of a beam control system and is used to illustrate basic servo control functions. A tracking telescope and optical sensor are mounted on the elevation over azimuth gimbal. Their purpose is to generate an electronic image of the target and send it to the tracker. This tracker is a special purpose computer which then processes the target image, identifies the desired aim point and measures the angle between it and the optical boresight of the telescope. Its output is a command to the gimbals to rotate until the optical axis of the tracking telescope is following the target and pointing at the aim point. If the gimbals are mounted on a moving or vibrating platform, these disturbances introduce additional tracking errors. Unlike target motion, this base motion disturbance can be directly measured using gyros and accelerometers which are attached to the telescope. This package, called an Inertial Reference Unit (IRU), provides an additional command to the gimbals which stabilizes the telescope and improves the tracker's ability to measure target motion errors. The HEL, shown simply in this cartoon as a box, provides the weapon beam to a pointing telescope which is then mechanically boresighted (optical axis made parallel) to the tracking telescope. Finally, the range to the target must be measured so that a parallax correction can be applied to the pointing telescope. This slightly tilts its optical axis to intersect the tracking telescope's optical axis at the range of the target and thus place the HEL beam on the aim point. UNCLASSIFIED/ fFOA QFFl€1AL WSE 8NLY 13
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 31 pages are in the text index: search them above, or from the library's search.