星载激光对水下目标探测中的激光传播损耗与可探测深度研究

Study on Laser Propagation Loss and Detectable Depth of Spaceborne Laser in Underwater Target Detection

摘要:

星载蓝绿激光对水下目标探测不受地理位置限制，通过反射的蓝绿激光信号实现有效探测，增强水下目标的隐蔽性。为解决激光能量衰减问题，本文建立完整的能量传输模型，涵盖自由空间、大气、大气-海水交界、水下及目标表面衰减，分析各部分衰减的影响因素。通过分析蓝绿激光在传输过程中的五步衰减，激光器发射峰值功率需达到20GW以满足链路能量需求。深入分析探测深度与卫星轨道高度、海水衰减系数、水面风速、激光发射能量之间的关系。随着轨道高度增加，探测深度逐渐减小，在100km至2000km的轨道高度范围内，探测深度急剧下降；超过2000km后，减小程度放缓。在600km、2000km、15000km和36000km的轨道高度下，探测极限深度分别为154.92m、144.89m、128.10m和120.80m。本研究为星载激光水下探测系统设计提供了理论依据。

Abstract:

Satellite-based blue-green laser underwater target detection is not limited by geographical location and enables effective detection through reflected blue-green laser signals, enhancing the concealment of underwater targets. To address the issue of laser energy attenuation, this paper establishes a comprehensive energy transmission model that includes free-space, atmospheric, air-water interface, underwater, and target surface attenuation, analyzing the influencing factors for each type of attenuation. By analyzing the five-step attenuation process of blue-green laser transmission, it is determined that the laser emitter’s peak power must reach 20 GW to meet the energy requirements for the communication link. The relationship between detection depth and satellite orbit altitude, seawater attenuation coefficient, sea surface wind speed, and laser emission energy is also thoroughly analyzed. As the orbit altitude increases, the detection depth gradually decreases. In the range of 100 km to 2000 km, the detection depth sharply declines; beyond 2000 km, the decrease in depth slows down. Specifically, at orbital altitudes of 600 km, 2000 km, 15000 km, and 36000 km, the maximum detection depths are 154.92 m, 144.89 m, 128.10 m, and 120.80 m, respectively. This study provides a theoretical basis for the design of satellite-based laser underwater detection systems.