Introduction

Meridian passage of an observed heavenly body, ie the sun, occurs when the body is directly over the observer’s meridian and the local hour angle (LHA) is zero. During this course we will only be covering the meridian passage (mer pass) of the sun. Those who wish to become navigating officers will cover the mer pass of the other heavenly bodies when they further their studies at the Cape Peninsula University of Technology (CPUT).

We use the data obtained during mer pass in order to determine the observer’s latitude. In order to do this we need the precise time of mer pass on the observe r’s meridian, the true altitude and the declination of the sun, both at that time. How do we go about it?