Developing a new calibrated pressure sensor for the Ocean Observatories Initiative Cabled Array and other applications

为海洋观测站计划电缆阵列和其他应用开发新型校准压力传感器

• 批准号: 1829486
• 负责人: William Wilcock
• 金额: $ 54.53万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1829486&HistoricalAwards=false
• 关键词: Developing; new; calibrated; pressure; sensor

Measurements of seafloor pressure are useful for understanding the earth and the ocean because they are sensitive to changes in the height of the seafloor and the weight of the overlying water and atmosphere. The best pressure sensors drift unpredictably so their output cannot be used to resolve long terms signals such as the steady buildup of strain between subduction zone earthquakes and long term changes in the mass of the oceans. Drift also makes existing pressure sensors less sensitive to shorter-term signals such as those from slow-slip earthquakes and ocean eddies. A new method has been developed to remove drift using the internal pressure inside the instrument housing as a reference and has been tested successfully with a seafloor prototype. This project will redesign the prototype so that the instrument is more robust, better calibrated, more compact and lower power. It will be attached to the Ocean Observatories Initiative Cabled Array on Axial Seamount, a volcano that is inflating rapidly following an eruption in 2015. The engineering effort will be led by a female engineer in a field where women are underrepresented and the project will train a graduate student in a technical project where they will learn to work with both engineers and scientists. The cruises that service and deploy instruments on the Ocean Observatories Initiative Cabled Array incorporate a large number of undergraduate students, and one will be engaged to conduct a project related to this instrument.The A-0-A method is a new approach to calibrating pressure sensors to remove drift. Periodically, a valve is used to switch the pressure sensor for a short interval from measuring the pressure in the ocean to measuring the pressure inside the instrument housing. The drift can then be determined by comparing the pressure readings to an accurate barometer. The A-0-A method has the potential to substantially reduce the drift of long-term seafloor pressure records in a much more economical way than current approaches. The first non-proprietary seafloor tests at 900 m in Monterey Bay on the MARS cabled observatory suggests that A-0-A calibrations may reduce pressure sensor drift to as little as 1-2 mm/year in 1000 m of water. However, design improvements are required to remove known sources of error and a side-by-side seafloor test is essential to verify the technique against established methods of drift removal. The first deployment of the redesigned instrument on Axial Seamount will allow comparisons with the absolute pressure measurements of the Scripps Institution of Oceanography Self-Calibrating Pressure Recorder (an instrument that uses a dead weight tester for periodic calibrations) and the relative pressure measurements obtained from repeat closed-loop mobile pressure recorder surveys, both of which have an uncertainty of ~1 cm of water. The cabled sensor can then be used for future vertical geodetic studies of the Cascadia subduction zone megathrust aimed at understanding patterns of fault locking, creep and slow slip.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

海底压力的测量有助于了解地球和海洋，因为它们对海底高度的变化以及上覆水和大气的重量很敏感。 最好的压力传感器会发生不可预测的漂移，因此它们的输出无法用于解析长期信号，例如俯冲带地震之间的应变稳定积累和海洋质量的长期变化。 漂移也使得现有的压力传感器对诸如慢滑地震和海洋漩涡等短期信号不太敏感。开发了一种新方法，以仪器外壳内的内部压力为参考，消除漂移，并已成功地与海底原型进行了测试。 该项目将重新设计原型，使仪器更强大，更好地校准，更紧凑，更低的功耗。 它将连接到轴向海山上的海洋观测站倡议电缆阵列，该火山在2015年爆发后正在迅速膨胀。 工程方面的工作将由一名女性工程师领导，该领域的妇女代表性不足，该项目将在一个技术项目中培训一名研究生，他们将学习与工程师和科学家一起工作。 为海洋观测站倡议电缆阵列提供服务和部署仪器的巡航考察包括大量本科生，其中一名学生将从事与该仪器有关的项目。A-0-A方法是一种校准压力传感器以消除漂移的新方法。 周期性地，阀用于在短时间间隔内将压力传感器从测量海洋中的压力切换到测量仪器壳体内部的压力。 然后，通过将压力读数与精确的气压计进行比较，可以确定漂移。A-0-A方法有可能大大减少长期海底压力记录的漂移，其方式比目前的方法经济得多。 在蒙特利湾900 m处的MARS电缆观测站进行的首次非专有海底测试表明，A-0-A校准可以将1000 m水下的压力传感器漂移降低至1-2 mm/年。 然而，需要改进设计，以消除已知的误差来源，并排海底试验是必不可少的，以验证该技术对既定的漂移消除方法。 重新设计的仪器首次部署在轴向海山后，将可与斯克里普斯海洋学研究所自校准压力记录仪（一种使用静重测试仪进行定期校准的仪器）的绝对压力测量值和通过重复闭环移动的压力记录仪勘测获得的相对压力测量值进行比较，这两种测量值的不确定度都在水深约1厘米处。电缆传感器可用于未来卡斯卡迪亚俯冲带巨型逆冲断层的垂直大地测量研究，旨在了解断层锁定，蠕变和缓慢滑动的模式。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。