Longitude Latitude

Latitude/Longitude A way to describe our location on the earth Tells how far north/south and east/west These are called coordinates N W E S

Latitude Lines Equator – 0o The lines run east and west, but they measure degrees north or south of the equator.

Run north and south. Where do all the lines meet? Longitude Lines Instead of measuring from the equator, longitude is measured from the prime meridian, a line running through Greenwich, England. Prime Meridian – 0o Run north and south. Where do all the lines meet?

By combining latitude and longitude We can pinpoint any location on Earth.

We measure latitude and longitude in degrees. There are 360 degrees in a circle. One degree is 1/360th the way around the earth.

We identify points on the Earth by specifying how many degrees North or South (of the equator) And how many degrees East or West (of the prime meridian) the points are located.

Many computer programs, such as GIS software, use this method. Another way to describe coordinates is to use a “+” or “-” instead of north, south, east, or west. North is “+” East is “+” South is “-” West is “-” Many computer programs, such as GIS software, use this method.

If you are inputting data into a GIS program, you will need to use “+” or “-” . Huntsville, Alabama is at: 34.72o North 86.62o West The answer: +34.72 degrees and -86.62 degrees. When inputting to a GIS, the + is assumed. How would you write this using “+” and “-”?

So you don’t have to worry about “+” or “-” The GLOBE website has buttons to click for North and South, when creating your Study Site definition. So you don’t have to worry about “+” or “-”

Fractions of a degree X Decimal Degrees = XX.xxxxxo Degree/minute/second = XXo xx’ xx’’ A minute is 1/60th of a degree – a second is 1/60th of a minute. Decimal Degrees = XX.xxxxxo We use… 86o 28’ 32” is NOT EQUAL to 86.2832o Be sure your GPS is set for decimal degrees!

Need help? Check out “Setting up your GPS” at www.globeinalabama.org - go to “Teaching Materials” Your GLOBE in Alabama specialists: Jerry Cobbs jerry@globeinalabama.org (256) 961-7864 Lynn Vaughan lynn@globeinalabama.org