Numbers used to define location are scientific measurements in the same sense as any measured variable. The rules governing the accuracy and precision of numeric information apply. Regardless of the notation used (DD vs DM vs DMS), the precision of a GCS coordinate pair should reflect the accuracy of the method used to determine the values. The table below shows the range of coordinate pair precision generally encountered in our work. The table also includes application examples associated with various levels of precision.
Notation
|
Rounded To Nearest
|
N-S Dist
|
|---|---|---|
Decimal degree
DD |
hundredth degree
ddd.dd |
1,110 m
|
thousandth degree
ddd.ddd |
111 m
|
|
10-thousandth degree
ddd.dddd |
11.1 m
|
|
100-thousandth degree
ddd.ddddd |
1.1m
|
|
one millionth degree
ddd.dddddd |
0.1m
|
|
Degree minute
DM |
whole minute (degree/60)
ddd° mm’ |
1,850 m
|
tenth minute
ddd° mm.m’ |
185 m
|
|
hundredth minute
ddd° mm.mm’ |
18.5 m
|
|
thousandth minute
ddd° mm.mmm’ |
1.9 m
|
|
Deg minute second
DMS |
whole second (minute/60 or degree/3600)
ddd° mm’ ss” |
30.8 m
|
tenth second
ddd° mm’ ss.s” |
3.1 m
|
|
hundredth second
ddd° mm’ ss.ss” |
0.3 m
|
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