Development of a Seafloor Piston Pressure Gauge for Vertical Marine Geodesy

PIs要求资助开发和测试用于海底的参考压力表。该仪器将以市售活塞计校准系统为基础，对其进行了修改，以适应海底的自动化操作。活塞计校准系统将校准质量加载到液压活塞上以产生压力；通过确定质量值、活塞尺寸和局部重力加速度，可以在绝对意义上准确地知道压力。这样的系统可以转换成一个压力基准，一个单值压力源。通过将海底压力表与参考压力进行原位比较，可以明确地确定并从时间序列中去除压力表漂移。压力基准只需要稳定和高度可重复性，这具有显著的计量优势。基于商用仪器的参考可以实现漂移控制，不确定度仅为百万分之几，或在2000米深处每年1厘米。更广泛的影响拟议的工作可能会导致海底压力仪器的重要进展，以测量深海深处的地壳（海底）运动。海底传感器的漂移问题一直是这些设备用于精确测量垂直运动的一个限制。这种方法如果成功，将有助于大地测量学、构造学、海洋地质学、物理海洋学和气候研究的研究人员。通过提供一个参考压力信号来校准和消除压力表漂移，提高长期海底压力表测量的绝对精度，这将允许使用易于部署的海底压力表进行长期大地测量，并且还将在海底和海底观测站中有其他应用。通过在会议上发表报告和发表同行评议的论文，这些机构在与海洋学界分享其研究和仪器开发成果方面有着良好的记录。

The PIs request funding to develop and test a pressure gauge reference for use on the sea floor. This instrument will be based on commercially available piston gauge calibrations systems, modified for automated operation on the seafloor. A piston gauge calibration system uses a calibrated mass loaded onto a hydraulic piston to generate a pressure; the pressure can be accurately known in an absolute sense by determining the mass values, piston dimensions and the local acceleration of gravity. Such a system can be transformed into a pressure reference, a single-valued pressure source. By in-situ comparing a sea-floor pressure gauge with a pressure reference, the pressure gauge drift can be unambiguously determined and removed from the time series. The pressure reference need only be stable and highly reproducible, which presents significant metrological advantages. A reference based on commercially available instruments could achieve drift control with uncertainties of only a few parts per million, or 1 cm/year at depths of 2000 meters. Broader ImpactsThe proposed work could potentially lead to an important advance in bottom pressure instrumentation to measure crustal (ocean bottom) movement in at deep ocean depths. The drift issue of bottom ocean sensors depth sensors have been a limitation in these devices uses to measure accurately vertical movements. This approach if successful will help researchers in geodesy, tectonics, marine geology, physical oceanography, and climate studies. Increasing the absolute accuracy of long-term seafloor pressure gauge measurements by providing a reference pressure signal to calibrate and allow removal of gauge drift would allow for usage of easily deployed seafloor pressure gauges for long-term geodetic measurements and would also have other applications in seafloor and subseafloor observatories. The PIs have an excellent record of sharing the results of their research and instrument development with the oceanographic community through presentations at meeting and publication of peer-reviewed papers.