In order to report your observations, you will need to know the geographic coordinates for your location, your latitude and longitude (Lat/Lon).  Here are some suggestions for finding these coordinates:

See the frequently asked questions below for more help in finding your Lat/Lon.

Latitude describes your distance from the Earth’s equator and is measured in angular degrees, with 0 degrees being the equator.  The North Pole is +90 degrees and the South Pole is -90 degrees. Latitude is also described as being either “North” or “South,” depending on your position in relationship to the equator.  Positive latitude values are indicated by “North” and negative values are indicated by “South."

Longitude is the angular measurement either east or west from the Prime Meridian, which runs through Greenwich, England.  Longitude increases as you leave the Prime Meridian (0 degrees) going east (0 to 180 degrees) and decreases as you head west (0 to -180 degrees), until they meet at 180 degrees.  Positive longitude values are also indicated by “East” and negative values are indicated by “West."

It is very important that you use the correct directions in your coordinates!  Here are some guidelines:

General Location Latitude Longitude
North America North, + West, -
South America South, - West, -


Frequently Asked Questions:

“I have a GPS receiver or can borrow one.  How do I determine my location?”
Take the GPS receiver outside to the location where you are observing, and turn it on.  In a few seconds, the GPS receiver will display the coordinates.  You may need to refer to the Users’ Manual to set the receiver to display the coordinates, as some receivers also display your location on an electronic map.  Most receivers will display coordinates in either “Degrees, Minutes, and Seconds” or “Decimal Degrees.”  If you have a choice, select Decimal Degrees.  Be sure you understand which number is latitude and which is longitude!  When you record your location, it is critical to write down all the decimal places.  Your coordinates should have at least 4 or 5 decimal places.

“I don’t have a GPS receiver or access to a Web browser?  Can I still participate?
Sure!  Try to find a topographic map of your location.  You can then use a ruler and a little math to determine your location.  If your school doesn’t have one, try a nearby library.  Many libraries have topographic maps of the local area, or know where to get one. Show me how - Visit and