Guide for Converting Latitude/Longitude Coordinates

Fractions of degrees are broken down into minutes and seconds. Each minute represents 1/60th of a degree and each second represents 1/60th of a minute (or 1/3600th of a degree). Below are the steps of converting from an angle in degrees-minutes-seconds to decimal degrees and back to degrees-minutes-seconds.

         EXAMPLES:

D = Degrees
M = Minutes
S = Seconds
.m = Decimal Minutes
.s = Decimal Seconds
         
DM.m = Degrees, Minutes, Decimal Minutes (ex. 45o22.6333);
D.d = Degrees, Decimal Degrees (ex. 45.3772o);
DMS = Degrees, Minutes, Seconds (ex. 45o22'38");
         

Process for Converting Latitude/Longitude Coordinates:

1) DMS --> DM.m  (45o22'38" --> 45o22.6333):
         
     - Divide S by 60 to get .m (38/60=.6333)
     - Add .m to M to get M.m (22+.6333=22.6333)
         
2) DM.m --> D.d  (45o 22.6333 --> 45.3772):
         
     - Divide M.m by 60 to get .d (22.6333/60=.3772)
     - Add .d to D to get D.d (45+.3772=45.3772)
         
3) D.d --> DM.m  (45.3772 --> 45o22.6333):
         
     - Multiply .d by 60 to get M.m (.3772*60=22.6333)
         
4) DM.m --> DMS  (45o22.6333 --> 45o22'38"):
         
     - Multiply .m by 60 to get S(.6333*60=38)
         

Notes specific to latitude/longitude coordinates and Satloc:

1) For manual entry of coordinates into the airplane's Satloc equipment, make sure the input coordinates are in DM.m format.

2) To create a file for uploading to Satloc, the coordinates need to be in D.d format. Make sure the longitude is preceeded by a minus sign.

Virginia Gypsy Moth Information Systems Lab roberts@vt.edu