What are Altitude and Azimuth?
I have just received a GeoClock program that runs on my PC. It graphically shows the position of the sun and gives figures for Azimuth and Elevation. I'm confused about what Azimuth and Elevation mean in reference to plotting the sun's course across the sky. Does one represent the position from North to South and the other represent the position East to West? This is very basic, but its been so long that I have used this information that I've lost track. Thanks for your help!
Azimuth represents the cardinal direction in which the object (in this case, the sun) can be found. It varies between 0 and 360 degrees. 0 degrees would be north, 90 east, 180 south, and 270 west.
Once you know in which direction the object is located, you need to know how high in the sky to look for it. That's where Altitude comes in. Altitude ranges from 0 to 90 degrees, and measures the angle between the horizon, you, and the object. An object with 0 degrees altitude is right on the horizon, while an object at 90 degrees altitude is directly overhead. If you stretch out your arm and make a fist, then your fist covers about 10 degrees on your field of vision, so if the sun is at 40 degrees altitude, it is about 4 outstretched fists above the horizon.
Occasionally, you will see altitudes less than zero, e.g. "At 9:30 PM, the sun will be at -20 degrees altitude." In this case, the sun would be 20 degrees below the horizon, you would be unable to see it, and it would be night time.
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist
This page has been accessed 65276 times since May 21, 2002.
Last modified: September 20, 2002 4:51:27 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)