# Section III: Latitude and Longitude

Section III of the Sight Reduction Form is used to find the Local Hour Angle (** LHA**) and

**of a celestial body. These are the two angles which define the position of a celestial body on the celestial sphere. Together with**

*Declination**, these will be used to find the values needed to plot a Line of Position.*

**Assumed Latitude**- We’ll look at Greenwich Hour Angle (
) in our first video.**GHA** - Our second video explains how to calculate the Local Hour Angle (
). This value will be used in the*LHA**Sight Reduction Tables*. - Our third video, Declination, covers this calculation which determines the celestial body’s position relative to the celestial equator.
- Our final video for Section III, Assumed Latitude, will walk through how to use
to determine whether we use “Same” or “Contrary” in the*Declination**Sight Reduction Tables*.

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