What is a tide gauge?
潮位计是干什么的？

Be it analog, acoustic, or microwave, a tide gauge measures changes in sea level relative to a datum (a height reference).
潮位计采用模拟，声学或微波等方法以测量记录海面相对于深度基准面的变化。

The rise and fall of the tides play an important role in the natural world and can have a marked effect on maritime-related activities. The image above shows the NOAA San Francisco Tide Station, in operation for more than 150 years.
潮汐的上升和下降在自然世界中起着重要作用，并且可以对与海洋有关的活动产生显着影响。上图显示了运行了150多年的NOAA（National Oceanic and Atmospheric Administration美国国家海洋和大气管理局）旧金山验潮站。

A tide gauge, which is one component of a modern water level monitoring station, is fitted with sensors that continuously record the height of the surrounding water level. This data is critical for many coastal activities, including safe navigation, sound engineering, and habitat restoration and preservation.
潮位计是现代水位监测站的组成部分，装有传感器，可连续记录周围水位的高度。这些数据对于许多沿海活动至关重要，包括安全航行，测深工程以及栖息地的恢复和保护。

Before computers were used to record water levels (especially tides), special "tide houses" sheltered permanent tide gauges. Housed inside was the instrumentation—including a well and a mechanical pen-and-ink (analog) recorder—while attached outside was a tide or tidal staff. Essentially a giant measuring stick, the tide staff allowed scientists to manually observe tidal levels and then compare them to readings taken every six minutes by the recorder. Tide houses and the data they recorded required monthly maintenance, when scientists would collect the data tapes and mail them to headquarters for manual processing.
在使用计算机记录水位（尤其是潮位）之前，特殊的“潮位站”用于保护永久性的潮汐仪。站内装有仪器，包括一口井和一台机械式笔墨（模拟）记录仪，而站外则安装有水尺。水尺实质上是一个巨大的竖尺，它使科学家能够人工观察潮位，然后将其与记录仪获取的六分钟间隔读数进行比较。潮位站和它们所记录的数据需要按月维护，同时科学家们将收集数据记录带并将其邮寄给总部以进行人工处理。

Before computers, special "tide houses" were constructed to shelter permanent water level recorders, protecting them from harsh environmental conditions. In this diagram, we can see how the analog data recorder is situated inside the house with the float, and the stilling well located directly beneath it. Attached to one of the piers' pilings is a tidal staff. This device would allow scientists to manually observe the tidal level and then compare it to the readings taken by the analog recorder.

在计算机出现之前，人们建造了特殊的“潮位站”来安置永久性的水位记录仪，以保护它们免受恶劣的环境条件的侵害。 在此图中，我们可以看到模拟数据记录仪是如何放置在带有浮子的站内，以及位于其正下方的静水井。 附在码头的一个桩上的是水尺。 该装置将使科学家能够人工观察潮位，然后将其与模拟记录仪的读数进行比对。

While similar in design to older tide houses, newer tide station enclosures are designed to protect sensitive electronics, transmitting equipment, and backup power and data storage devices. The older stilling well has been replaced with an acoustic sounding tube and the tidal staff with a pressure sensor. The new field equipment is designed to operate with the highest level of accuracy with a minimum of maintenance, transmitting data directly back to NOAA headquarters for analysis and distribution.

与旧潮位站设计类似，新型潮位站被设计用于保护敏感的电子设备，传输设备以及备用电源和数据存储设备。 较旧的静水井已被换成声学测深管，而水尺已被压力传感器所取代。 新的现场设备旨在以最低的维护成及最高的准确度运行，将数据直接传输回NOAA总部进行分析和发布。

The computer age led to tide gauges that use microprocessor-based technologies to collect sea-level data. While older tide-measuring stations used mechanical floats and recorders, modern monitoring stations use advanced acoustics and electronics. Today's recorders send an audio signal down a half-inch-wide "sounding tube" and measure the time it takes for the reflected signal to travel back from the water's surface. Data is still collected every six minutes, but while the old recording stations used mechanical timers to tell them when to take a reading, a Geostationary Operational Environmental Satellite (GOES) controls the timing on today's stations.

计算机时代导致潮位计使用基于微处理器的技术来收集海平面数据。较早的潮汐测量站使用机械浮标和记录仪，而现代化的监测站则使用先进的声学和电子设备。如今的记录仪发送音频信号向其下的半英寸宽“测深管”，并测量反射信号从水面传播回来所需的时间。仍然每六分钟收集一次数据，但与旧记录站使用的机械计时器相比，对地静止轨道环境卫星(Geostationary Operational Environmental Satellite (GOES))控制着今天的台站的时间。

In addition to measuring tidal heights more accurately, modern water level stations are capable of measuring 11 other oceanographic and meteorological parameters, including wind speed and direction, air and water temperature, and barometric pressure. NOAA uses this information for many purposes, among them to ensure safe navigation, record and predict sea-level trends and other oceanographic conditions via nowcasts and forecasts, and publish annual tide predictions.

除更准确地测量潮汐高度外，现代水位站还能够测量其他11种海洋和气象参数，包括风速和风向，空气和水温以及大气压。 NOAA将这些信息用于许多目的，其中包括确保安全航行，通过即时预报和近期预报记录和预测海平面趋势和其他海洋状况，以及发布年度潮汐预测。

译自：https://oceanservice.noaa.gov/facts/tide-gauge.html