Shipborne Laser Research Articles

From the development of shipborne laser weapon of U.S. navy to analyze the military requirements and countermeasures of navy

In recent years, U.S. navy is exposing frequently some tests and development about shipborne laser weapon, which have attracted aboard attention and passionate discussion. In this paper, the review on shipborne laser weapon of U.S. navy from the 21th century is summed up. Some oppugns or baffles are also analyzed in this process. The meaning on developing shipborne laser weapon is discussed more deeply. Furthermore, some advices are put forward.

Technology readiness level assessment on ship-borne laser weapon system

Technology readiness level assessment on ship-borne laser weapon system

Nonlinear and Robust Location for Low-cost Shipborne Laser Ranging Positioning

ABSTRACTWithout landing on islands, reefs, or facilities, fast locating targets by the reflectorless ranging integrated with Global Navigation Satellite System (GNSS) has a wide range of application. We propose a nonlinear robust location method and modify current nonlinear estimators for achieving shipborne laser ranging positioning of high precision. The Newton method is recommended as a nonlinear estimator for shipborne ranging positioning since the Gauss–Newton method occasionally fails in critical cases when the control points and the unknown point are approximately coplanar. However, it shows that the vertical positioning based on the shipborne laser ranging is generally of low precision, while the vertical angle measurement is used to further remedy this deficiency. The positioning precision and reliability might be significantly decreased with the increased number of gross errors in the observations that are dynamically implemented on a moving shipborne platform; thus a weighting scheme with high breakdown point is recommended to set the preliminary weights, and then Scheme III of the Institute of Geodesy and Geophysics of China (IGGIII) is applied to iteratively updating the weights of distance observations. It shows that the proposed method based on the angle-distance observational data fusion can be used to achieve a three-dimensional positioning of high precision.

美国海军舰载激光武器研究进展

美国海军舰载激光武器研究进展

舰载激光武器的发展历程及趋势分析

Shipborne laser weapons provide complements for traditional shipborne weapons and they have been given much attention by many countries in the world.This paper introduces the history of shipborn laser weapons,and analyzes their compositions,functions and key technologies.Then,it points out that the development of shipborne laser weapons will focus on the free electron lasers and optical fiber lasers,and the low-energy lasers with small weights and volumes are expected to used in shipborne laser weapons.Actually,the shipborne laser weapons will develop toward the direction of miniaturization and high efficiency.

Scatterings

Boosting precision and stability of optical lattice clocks; metallic beetles bring bling; ship-borne laser zaps target a mile away; better nanoparticle detection sensitivity with optical microcavities.

Research on Laser Weapon Soft Damage to IR Seeker

Aiming at ship-borne laser weapon damage to anti-ship missile, laser soft damage to IR seeker was researched. First, link model on laser disturbance to anti-ship missile IR detector was set up. Laser atmospheric transmittance on the sea was deduced. 1.06μm laser atmospheric transmittance on the sea was calculated. The relationship was obtained among atmospheric transmittance and visibility and elevation. Then 10.6μm laser atmospheric transmittance curve was described. The curve is changed by visibility and propagation distance. And then the experiment on laser disturbing CCD imaging system was accomplished. Pixel saturation threshold was measured. CCD saturation power density threshold was also measured. The curve was described. The curve is changed by laser incident energy and CCD saturation area ratio. Saturated area is increasing rapidly with the laser energy increasing; when laser energy is low. Saturated area is increasing slowly with the laser energy increasing; when laser energy is large. Finally, 1.06μm laser was given as an example, the necessary laser energy which can disturb effectively anti-ship missile IR detector was calculated. Some valuable data and conclusions were gained.

美国海军舰载激光武器研发进展与趋势

美国海军舰载激光武器研发进展与趋势

Continuous measurements of chlorophyll-a concentration in the Pacific Ocean by shipborne laser fluorometer and radiometer: Comparison with SeaWiFS data

The results of comparisons of chlorphyll-a concentrations, measured using different methods in various regions of the Pacific, are presented. The measurements were made simultaneously from a moving ship using both a laser fluorometer and a spectrometer for measurements of the spectral distribution of the upwelling radiation. Two-band and multispectral algorithms were used to derive the pigment concentration from the upwelling radiation. The chlorophyll a concentrations measured by the shipborne instruments are compared with data obtained by SeaWiFS (the Sea-viewing Wide Field-of-View Sensor).

A Shipborne Laser Fluorimeter for Studying Sea-Water Fluorescence Spectra

A shipborne laser fluorimeter making it possible to determine promptly the concentration of chlorophyll A in sea water is described. The measurement error is ∼35% at chlorophyll concentrations of ∼0.1–3 μg/l, and the single-measurement duration is ∼1 min.

Shipborne Laser Beam Weapon System for Defence against Cruise Missiles

Sea-skim~ing cruise missiles pose the greatest threat to a surface ship in the present-day war scenario. The convenitional close-in-weapon-systems (CIWSs) are becoming less reliable against these new challenges requiring extremely fast reaction time. Naval Forces see a high energy laser as a feasible andjeffective directed energy weapon against sea-skimming antiship cruise missiles becauseof its .ability to deliver destructive energy at the speed of light on to a distant target. The paper comparesthe technology and capability of deuterium fluoride (DF) and chemical-oxygen-iodine laser (COIL) in effectively performing the role of a shipborne CIWS altainst sea-skimming missiles. Out of these twolasers, it is argued that DF laser wo.uld be more effective a,s a shipborne weapon for defence against sea-skimmin,g cruise missiles. Besides the high energy laser as the primary (killing) laser, othersub-systems required in the complete weapon system would be: A beacon laser to sense phase distor'ions in the primary laser, adaptive optics to compensate the atmospheric distortions, beam-directing optics, illuminating lasers, IRST sensors, surveillance and tracking radars, interfacing system, etc.

Use of a ship-borne laser fluorosensor for remote sensing of chlorophyll a in a coastal environment

In vivo fluorescence of chlorophyll a (chl a) was measured, with a ship-borne lidar (light detecting and ranging) system and with an in situ fluoroineter and a laboratory spectrofluoronwter, in a frontal region separating the runoff plume of the Gripe Current and marine waters of the Anticosti Gyre in the St. Lawrence Estuary, during daytime and nighttime. These fluorescence measurements were compared with extracted chl a concentrations from water samples. The results showed that lidar can. produce accurate synoptic estimates of surface chl a concentrations. The lidar instrument measured a variable fluorescence intensity F, which lies between the ground (F 0) and maximum ( F m) fluorescence intensity of chl a.8 The slope of the linear regression of lidar F against extracted chl a was steeper and less variable during the night than during the day. Monitoring of all variables over a 24-h period showed that photosynthetically available radiation (PAR) up to 100 W m −2 did not significantly reduce lidar fluorescence-that is, up to 90 min after sunrise tinder cloud free conditions. In the context of lidar remote sensing from an. aircraft, dawn flights will allow measurements of F that lie close to dark-adapted values and that are little affected by PAR. At this time of day, light conditions would be adequate for safe low-attitude flights.