# Orientation Layer Values in QGIS, What represents North? [closed]

I have an orientation raster layer in QGIS. In band 1 I have the orientation values, wich are between 0º and 360º. Is 0º the North orientation an 180º south??

## closed as unclear what you're asking by underdark♦Sep 14 '16 at 18:07

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• Welcome to gis.stackexchange! Please edit the title of your question to include enough information for future visitors to be able to find this thread when looking for the same problem. – underdark Sep 13 '16 at 20:06
• Unless I'm missing something, it's impossible for us to answer this question because we don't know anything about your raster layer. You would need to look at the metadata for it to be absolutely sure what those values represent. – Dan C Sep 14 '16 at 16:19

## 1 Answer

I would have assumed the same as you did, that 0 degrees is north and 180 degrees is south, just as it works on a compass. But according to Wikipedia,

Modern digital GIS maps such as ArcMap typically project north at the top of the map, but use math degrees (0 is east, degrees increase counter-clockwise), rather than compass degrees (0 is north, degrees increase clockwise) for orientation of transects. Compass decimal degrees can be converted to math degrees by subtracting them from 450; if the answer is greater than 360, subtract 360.