How to Determine Your Location in Latitude and Longitude

If you ever want to share your phenology records with others, or have them included in other databases, you need to have the location of your observations in latitude and longitude.   The easiest way to determine a location is to borrow a GPS and take a direct reading.  This would preferably be  in decimal form, to 4 decimal places.  However, if you have a topographic map for your area, you can calculate your position from the map.  Many shire councils or state government agencies in rural areas will have topographic maps which you can probably use.  Although maps only give degrees and minutes, another source for geographical information on the internet is Geoscience Australia's Place Name Search.

If you want to convert your  map longitude and latitude to decimal form, use the following formula:

       decimal notation =  DEGREES + (MINUTES +SECONDS/60)
                                                                         60
 

So, as an example,  Macquarie University's position is 33^o 46'S, 151^o 07'E.  (This reading was obtained from the university automatic weather station, and doesn't include seconds.)  To convert:

                                    33 + 46/60 = -33.76666 = latitude
                                   151 + 7/60 = 151.11667  = longitude

When using this formula to convert to decimal notation, you should ignore the minus sign for latitude if you obtained your location from  Geoscience Australia's webpage.  As Australia is in the southern hemisphere, latitude must be a  negative number and longitude is positive in decimal notation.
 

There is an excellent discussion of latitude and longitude on the Canadian PlantWatch site.  This is well worth looking at to learn how to calculate your position.  The principles are exactly the same here in Australia, but you have to remember that we are in the South and East parts of the globe, whereas they are in the North and West sections.