In the Altitude-Intercept Method, what does Ho represent?

In the Altitude-Intercept Method, Ho represents the Height Observed, which is the actual celestial altitude measured with a sextant. This measurement is taken at a specific moment while navigating at sea, and it reflects the angle of a celestial body (like the sun or stars) above the horizon as seen from the observer's position.

The Height Observed is key in determining one's position on the earth's surface since it is used in calculations to compare against the calculated altitude (often represented as Hc) derived from navigational data. By comparing these two altitudes—Ho and Hc—navigators can assess their position and correct their course accordingly. Understanding this concept is fundamental in celestial navigation as it forms the basis for determining an accurate fix on the position at sea.