Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

Many scientific articles report site location in units of degree/min/sec, but for analysis in with non-GIS software, it is easier to use decimal degrees. Is there a reason for degrees / min / sec to be the more frequently used convention? What are the advantages and disadvantages to using one or the other?

clarification While I am generally interested in the advantages and disadvantages to using one or the other, my particular interest is in the context of reporting location in a scientific paper.

share|improve this question

5 Answers 5

up vote 6 down vote accepted

IMHO, the main reasons for DMS to be used in scientific publications is that it is what people are used to read. It is slightly easier for people to get a sense of distance and scale when speaking of minutes and seconds, instead of 0.37 decimal degrees. Many humans are well used to work with these coordinates and paper maps. That is changing.

Other than that, I agree with the other comments that it is a lot easier for machines to process DD.

share|improve this answer
    
Thats the only rationale that makes sense to me so far, and that this is ingrained into some journal style requirements. –  David Nov 17 '10 at 5:26

Degrees°/minutes′/seconds″ (DMS) also requires N E S W to be known i.e. which hemisphere you are working in.

wiki:"The tricky part comes in when you need to differentiate North/South latitude or West/East longitude"

Decimal Degrees require + or - to indicate this
Computers/Databases prefer this to DMS. Storage is minimised if you base it on 6 decimal places

share|improve this answer
    
is it also acceptable to report (as in a written report) decimal degrees with NESW instead of +/-? –  David Nov 15 '10 at 19:00
3  
sure, but coming from a technical angle, users get frustrated using DMS in GIS (not GPS) environments. takes longer to type ° ′ ″ than +/- (or even + is removed) so productivity is improved (slightly) –  Mapperz Nov 15 '10 at 19:12

Advantage DD: Programmatically, it is much simpler to store & use decimal degrees because you can simply use floating point or double types, as opposed to creating a custom type/class or parsing characters as you'd need to when using DMS.

share|improve this answer

The only time I have found DMS useful is when working directly with navigation charts, where the graticule is denominated in minutes/seconds. And I find myself on a sailboat so rarely these days. In all other cases I have cursed every interaction with DMS, which lends itself to a huge variety of syntactical forms (DD MM'SS" ? DD MM SS? DDMMSS? DD MM.MM? DD MM SS.SS?) and seems to be read by a fairly limited number of apps compared to decimal degrees.

share|improve this answer

advantages for either would be for specific use of the values. It is most likely possible in your gis software to maintain two or more "sets" of fields for each value you need (using the geometry calculator in arcgis). I know that I have maintained two in one layer I had for exporting to GPS and or as a track for a pilot to input dms (degree, minute, second) (e.i. helicopter pilots for locate observation, call for municipal flyover, etc.) there is also dd (decimal degrees) ddm (decimal minutes).

share|improve this answer
    
Legacy in another user interface (your pilot GPS) is not exactly an advantage of the system. ;) It may be arguably an advantage of your new system to support other formats. –  relet Nov 16 '10 at 9:36

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.