Before moving on, try the following exercises:

1. A star's observed altitude (Ho) is 19 degrees 17.1 minutes and the computed altitude (Hc) is 19 degrees 30.2 minutes. Where along the azimuth line do you mark your intercept?

The correct answer is b.

Because Ho < Hc, your intercept will be away from the GP.

2. On a plot, the line of position is perpendicular to the azimuth line. (Select True or False.)

The correct answer is a.

This statement is True. A line of position (LOP) is always perpendicular to the azimuth line.

3. Your position is located at the intercept of the line of position and the azimuth line. (Select True or False.)

The correct answer is b.

This statement is False. Your position is located somewhere along the line of position (LOP), but not necessarily at the intercept. Determining a location requires more than one LOP. Your location will be the intersection of the LOPs. This is why a minimum of three LOPs are often needed to obtain an accurate position.