The prime vertical is the reference point...

Question 1 / 2707066636ee928f7522a1c519ecb

Question 1 of 2707066636ee928f7522a1c519ecb

The prime vertical is the reference point from which the angle of which type of observation is measured?

Question 1 of 27070

The prime vertical is the reference point from which the angle of which type of observation is measured?

🔍 Key Concepts

• Prime vertical as a great circle on the celestial sphere • Difference between azimuth and amplitude in celestial navigation • When observations are made: at sunrise/sunset vs any time the body is visible

💭 Think About

• Ask yourself: along which circle on the horizon or sky do we measure this quantity—from north/south points or from east/west points? • Which of these options is specifically connected with sunrise and sunset, and which can be taken at any time a celestial body is visible? • Which quantity is defined as an angle between the celestial body and the true horizon, and which one is the angle measured at the time of rising/setting?

✅ Before You Answer

• Be clear on the definition of prime vertical (it passes through the east and west points of the horizon and the zenith). • Review the standard definition of azimuth vs amplitude in basic celestial navigation texts. • Verify which of the listed observations is explicitly defined as being measured from the prime vertical.

Question 1 of 27070

The prime vertical is the reference point from which the angle of which type of observation is measured?

Sextant angle

Azimuth

Amplitude

Local apparent noon