Meridian Passage occurs when a celestial body crosses the observer’s meridian of longitude and at that instant, it will reach its greatest altitude above the observer’s horizon.

Sep 10, 2018 · We use the Sun’s Meridian passage to get the second position line. In Mer-Pass, we measure the sextant altitude of the body when it is on the observer’s Meridian, i.e directly above the head of the observer.

Understanding Meridian Passage (Mer. Pas.). Applying the Equation of Time when calculating longitude at the Sun’s meridian Passage. Meridian Passage Short Method; Meridian Passage Long Method; Altitude Correction for Parallax; Altitude Correction for Semi-Diameter; Altitude Correction for Dip; The Astronomical Position Line

The short method involves calculating the time of local meridian passage at the vessel’s present geographical position shortly before noon and then measuring the Sun’s altitude as that time approaches. Outline of the Six-Step Proforma for the Meridian Passage Short Method.

A Meridian Passage is a quick method of getting a position line that happens to be your Latitude. This occurs once a day at your local noon, when the sun is directly overhead. In fact, its GHA will be the same as your Longitude. It is a lot simpler to work out, and does not require precise time. The first step is to find the time of the ‘mer pas’.

Meridian Passage Meridian passage of a heavenly body occurs when the body is on the same great circle of meridian as the observer’s. As all heavenly bodies circle around the pole, they will cross the observer’s meridian and also the observer’s anti …

The meridian passage of a celestial body is the time where it is at its highest point in the sky according to an observer. You can aim your sextant at the sun before merpass and keep watching it as it rises higher in the sky.