EAGER: Fiber-Optic Temperature Profiler for Long Duration Ballooning - Proof of Concept

EAGER：用于长时间热气球飞行的光纤温度分析仪 - 概念验证

• 批准号: 1419932
• 负责人: Lars Kalnajs
• 金额: $ 11.88万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-15 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1419932&HistoricalAwards=false
• 关键词: EAGER; Fiber; Optic; Temperature; Profiler

This is a project to develop a new technology for temperature profiling from super-pressure balloons that fly along constant density surfaces, typically in the stratosphere. The sensor is a fiber-optic temperature profiler (FTP), consisting of a 2-4km length of optical fiber suspended from the gondola of a balloon. Temperature is determined along the length of the fiber from the backscatter returned from a laser pulse injected at the top of the fiber. Changes in the temperature of the fiber lead to changes in Raman scattering (particularly the wavelengths of the stokes and anti-stokes lines), which can be inverted to retrieve temperature, and the timing of the laser pulses can be used to ascribe the temperature measurement to a specific linear position along the fiber. This technology is currently used for industrial applications (e.g. borehole temperature sensing in oil and gas drilling operations), and the sensors are commercially available. However, it requires substantial enhancement before it can be deployed from a balloon gondola.In addition to the core instrument, several other components must be developed to form a complete system. One of these is an end-of-fiber module which is weighted to make the fiber hang more or less vertically and contains a thermometer and a GPS receiver. The GPS receiver determines the position of the bottom end of the fiber, which is combined with a position fix from a GPS receiver in the gondola to estimate the altitudes of the temperature readings. Additional components include a data and control system and a fiber deployment system, the latter consisting of a spool that reels out the fiber once the balloon reaches altitude. Funds provided here will be used to develop a prototype and conduct a test flight.The work has scientific broader impacts due to the wide variety of potential applications of the system. The primary intended use of the system is for sounding the Tropical Tropopause Layer (TTL). There is considerable interest in the fine-scale temperature structure of the TTL, particularly as it relates to issues including the difference between cloud-top height and the height of the cold-point tropical tropopause, the minimum temperature of the TTL and its role in limiting the transport of water vapor into the stratosphere, and the temperature perturbations associated with vertically propagating gravity waves.

这是一个开发一种新技术的项目，通过沿恒定密度表面飞行的超压气球，通常在平流层中，来测量温度。该传感器是一个光纤温度分析器（FTP），由悬挂在气球吊斗上的2-4公里长的光纤组成。温度沿着光纤的长度由激光脉冲在光纤顶部注入后向散射返回确定。光纤温度的变化导致拉曼散射（特别是斯托克斯线和反斯托克斯线的波长）的变化，可以通过反转拉曼散射来获取温度，并且激光脉冲的定时可以用来将温度测量归因于沿光纤的特定线性位置。该技术目前用于工业应用（例如，石油和天然气钻井作业中的井眼温度传感），并且传感器已经商业化。然而，它需要大量的改进才能从气球贡多拉上部署。除了核心仪器外，还必须开发其他几个部件，以形成一个完整的系统。其中之一是一个光纤末端模块，它被称重以使光纤或多或少垂直悬挂，它包含一个温度计和一个GPS接收器。GPS接收器确定光纤底端的位置，并结合贡多拉GPS接收器的定位来估计温度读数的高度。附加组件包括一个数据和控制系统以及一个光纤展开系统，后者由一个线轴组成，一旦气球到达高度，该线轴就会卷出光纤。这里提供的资金将用于开发原型机和进行试飞。由于该系统的各种潜在应用，该工作具有更广泛的科学影响。该系统的主要用途是探测热带对流层顶层（TTL）。人们对TTL的精细尺度温度结构相当感兴趣，特别是因为它涉及的问题包括云顶高度和热带对流层冷点顶高度之间的差异，TTL的最低温度及其在限制水蒸气进入平流层的运输中的作用，以及与垂直传播重力波相关的温度扰动。