ATI: Backscattering and chirping laser guide star experiments at Palomar Observatory

ATI：帕洛马天文台的反向散射和啁啾激光导星实验

• 批准号: 0837646
• 负责人: Edward Kibblewhite
• 金额: $ 9.06万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-12-01 至 2009-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0837646&HistoricalAwards=false
• 关键词: ATI; Backscattering; chirping; laser; guide

Telescopes on the ground must observe objects in deep space through the interference of the earth's atmosphere. As light passes through the atmosphere it gets spread out by turbulence due to wind shear and changes in temperature and pressure within the atmospheric layers which effectively diminishes the resolving power of earth-based telescopes. This difficulty can be overcome to a large extent by relatively new techniques employing "Laser Guide Stars" and "Adaptive Optics." A bright laser illuminates a patch of sky near the target object. The laser's light is absorbed and then re-emitted by atoms in the upper atmosphere, above much of the interfering lower atmosphere. The return signal can then be used to track the time-dependent scattering of the light. Adaptive Optics uses this information to adjust optics in the telescope's instrumentation to restore the image to what would be seen from above the atmosphere. Unfortunately, Laser Guide Star technology is complex and expensive. Dr. Kibblewhite is pursuing a theoretical idea, confirmed by his computer simulations, that would significantly increase the amount of light returned from the atmosphere. This enhanced signal could then lead to better signal-to-noise and/or more rapid response to the atmosphere's changes, all at a lower cost. Dr. Kibblewhite will modify a laser and then use it on the Palomar Observatory's 5-meter Hale telescope to test his idea.

地面望远镜必须通过地球大气层的干扰来观察深空物体。 当光线穿过大气层时，由于风切变和大气层内温度和压力的变化，光线会被湍流扩散，这会有效地降低地球望远镜的分辨率。这种困难可以在很大程度上克服相对较新的技术，采用“激光导星”和“自适应光学”。“一束明亮的激光照亮了目标物体附近的一片天空。激光的光被吸收，然后被高层大气中的原子重新发射，高层大气中的原子位于大部分干扰的低层大气之上。 然后，返回信号可以用于跟踪光的时间依赖性散射。自适应光学利用这些信息来调整望远镜仪器中的光学器件，以将图像恢复到从大气层上方看到的图像。 不幸的是，激光引导星星技术复杂且昂贵。 Kibblewhite博士正在追求一个理论上的想法，他的计算机模拟证实了这一点，这将大大增加从大气层返回的光量。 然后，这种增强的信号可以导致更好的信噪比和/或对大气变化的更快响应，所有这些都以更低的成本进行。Kibblewhite博士将修改激光器，然后将其用于Palomar天文台的5米黑尔望远镜来测试他的想法。