Fairly easy process to describe: The letter, degrees and minutes will be the same in either notation, the decimal minutes are in 'milliminutes', and need to be separated from the left part of each coordinate, divided by 1000, then multiplied by 60.
Since dividing by 1000 then multiplying by 60 gives the same result as multiplying by 60/1000, and 60/1000 is the same as 0.060, which is equal to 0.06, we can skip the division and just multiply the decimal minute part by 0.06.
Expressed as a formula, that can be done as shown below:
The longitude and latitude of the GPS coordinates are entered into separate cells (B2 and C2).
The formula shown is entered in D2, then filled right to E2. The text copy below can be pasted into the formula editor for D2.
LEFT(B2,LEN(B2)−5)&"' "&ROUND(VALUE(MID(B2,FIND(".",B2)+1,3))×0.06,0)&""""
LEFT(B2,LEN(B2)−5)
This part gets left left part of the coordinate up to, but not including the decimal, last three digits and the minute sign at the end of the coordinate.
&"' "&
The ampersand is the concatenation operator. It connects the string on the left to the text (a minute sing and a space character) between the double quotes. The second ampersand connects the result of the rest of the formula to the string being built.
ROUND(VALUE(MID(B2,FIND(".",B2)+1,3))×0.06,0)
FIND finds the decimal point in the coordinate in B2, + adds 1, and the result is handed to MID
MID goes to the character determined by that number (the first digit after the decimal) and gets the three characters, starting at that position, and passes them (in order) to VALUE
VALUE converts the three character string to a number,
and ×0.06 multiplies that number by 0.06 to convert it to the equivalent number of seconds. and the result is handed to ROUND
ROUND rounds the result to the nearest whole second. and
&""""
The last concatenation operator attaches the seconds sign to the end of the string displayed in the cell.
Regards,
Barry
PS: If the GPS coordinates do not include a minute sign after the decimal minutes, change the -5 in the LEN function arguments to -4.
B.