# How to Calculate Azimuth

Yes, it's spherical trigonometry – but it's not rocket science! Azimuth is simply the angle of an object in the sky along the horizon.

### Instructions

- Step 1:
**Determine latitude and longitude**Determine the latitude and longitude of the starting point, or observation point, from which you'll calculate the angle. Use L to represent the starting point latitude. - TIP: Find latitude and longitude by going to the location with a GPS device.
- Step 2:
**Find object's coordinates**Find the latitude and longitude of the celestial object. Use D to represent the latitude of the point on the earth where the desired object is straight overhead. - Step 3:
**Find t**Find the meridian angle, represented by t, also known as the local hour angle – or LHA. It is the difference between the observer's longitude and the longitude of the celestial object. - Step 4:
**Calculate the altitude**Calculate the altitude of the object, called H. Multiply the sine of L by the sine of D. Then multiply the cosine of L by the cosine of D, by the cosine of t. Add these two products and determine the arcsine of the sum. - Step 5:
**Compute azimuth**Find the azimuth angle, Z, by multiplying the cosine of D by the sine of t, and dividing the product by the cosine of H. Then determine the arcsine of the result, which will give you the azimuth angle. - FACT: The distance between Earth and our moon is, on average, 238,900 miles.

### You Will Need

- The latitude and longitude of starting point
- The latitude and longitude of the celestial object
- A calculator with sine
- cosine
- and arcsine functions
- A chart or map (optional)
- A GPS device (optional)