- 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
- and arcsine functions
- A chart or map (optional)
- A GPS device (optional)