reduction of the ex-meridian altitude

简明释义

近中天高度订正

英英释义

例句

1.The pilot used the reduction of the ex-meridian altitude to adjust their flight path over the ocean.

飞行员使用经线外高度的修正来调整他们在海洋上的飞行路径。

2.During the celestial navigation class, we learned about the reduction of the ex-meridian altitude process.

在天文导航课程中，我们学习了经线外高度的修正过程。

3.The navigator performed the reduction of the ex-meridian altitude to accurately determine their position at sea.

导航员进行了经线外高度的修正以准确确定他们在海上的位置。

4.The reduction of the ex-meridian altitude is crucial for determining latitude when using a sextant.

在使用六分仪时，经线外高度的修正对于确定纬度至关重要。

5.In order to ensure accurate readings, the crew made a reduction of the ex-meridian altitude before taking measurements.

为了确保读数准确，船员在进行测量之前进行了经线外高度的修正。

作文

In the field of astronomy and navigation, the term reduction of the ex-meridian altitude refers to a crucial process used to determine the altitude of celestial bodies when they are not directly overhead. This concept is particularly important for navigators and astronomers who rely on accurate measurements to chart their courses or make observations. The reduction of the ex-meridian altitude involves adjusting the observed altitude of a celestial body based on its position relative to the observer's meridian. To understand this process, one must first grasp what 'ex-meridian' means. An ex-meridian altitude is the altitude of a celestial object measured at a time when it is not crossing the observer's local meridian. This situation often arises due to the time lag between the observation and the moment when the celestial body is at its highest point in the sky. The reduction process compensates for this delay by applying specific corrections based on the object's declination and the observer's latitude.The steps involved in the reduction of the ex-meridian altitude typically include calculating the zenith distance, which is the angle between the zenith (the point directly above the observer) and the celestial body. From there, navigators apply corrections based on the time difference from the meridian passage. This correction takes into account the Earth's rotation and the celestial body's apparent motion across the sky.For example, if a navigator measures the altitude of the sun at a certain time and finds it to be lower than expected, they would perform the reduction of the ex-meridian altitude to adjust their reading. By using tables of declination and latitude, they can accurately calculate the corrected altitude, which provides a more precise location fix.In practical terms, the importance of the reduction of the ex-meridian altitude cannot be overstated. For sailors navigating vast oceans, accurate celestial navigation is essential for ensuring safe passage. Similarly, astronomers depend on precise measurements to conduct their research and observations. The ability to reduce an ex-meridian altitude allows them to maintain accuracy even when conditions are less than ideal.Moreover, the principles behind the reduction of the ex-meridian altitude have applications beyond just traditional navigation and astronomy. Modern technologies, such as GPS and satellite positioning systems, also rely on similar concepts of positional accuracy and celestial mechanics. Understanding these foundational principles enriches our comprehension of how we navigate and observe the universe today.In conclusion, the reduction of the ex-meridian altitude is a vital technique in astronomy and navigation that enhances the accuracy of celestial observations. By correcting the altitude of celestial bodies based on their ex-meridian positions, navigators and astronomers can achieve reliable results. As technology advances, the relevance of these traditional methods remains significant, demonstrating the enduring nature of astronomical principles in our modern world.

在天文学和导航领域，术语外子午线高度的修正指的是一个关键过程，用于确定天体的高度，当它们不在正上方时。这个概念对于依赖准确测量来绘制航线或进行观测的导航员和天文学家尤为重要。外子午线高度的修正涉及根据天体相对于观察者子午线的位置调整观测到的高度。要理解这个过程，首先必须掌握“外子午线”的含义。外子午线高度是指在天体未穿过观察者当地子午线时测得的高度。这种情况通常由于观察与天体达到最高点之间的时间延迟而出现。修正过程通过基于天体的赤纬和观察者的纬度施加特定的修正来补偿这一延迟。在外子午线高度的修正中涉及的步骤通常包括计算天顶距离，即天顶（直接在观察者上方的点）与天体之间的角度。从那里，导航员根据从子午线经过的时间差施加修正。该修正考虑了地球的自转和天体在天空中的表观运动。例如，如果导航员在某个时间测量太阳的高度并发现其低于预期，他们将执行外子午线高度的修正来调整读数。通过使用赤纬和纬度的表格，他们可以准确计算出修正后的高度，从而提供更精确的位置修正。在实际操作中，外子午线高度的修正的重要性不容小觑。对于在浩瀚海洋中航行的水手而言，准确的天文导航对于确保安全航行至关重要。同样，天文学家依赖精确的测量来进行研究和观测。能够减少外子午线高度使他们即使在条件不理想时也能保持准确性。此外，外子午线高度的修正背后的原理不仅限于传统的导航和天文学。现代技术，例如GPS和卫星定位系统，也依赖于类似的定位准确性和天体力学概念。理解这些基础原理丰富了我们对当今如何导航和观察宇宙的理解。总之，外子午线高度的修正是天文学和导航中一项重要的技术，增强了天体观测的准确性。通过根据天体的外子午线位置修正高度，导航员和天文学家可以获得可靠的结果。随着技术的进步，这些传统方法的相关性仍然显著，证明了天文原理在我们现代世界中的持久性。