I'm new to QGIS and I have to calculate the slope of a DEM (I use srtm-data). I already detected the geoalgorithms toolbox and I also produced a raster layer with the slope using the tool "slope, aspect, curvature" (One can find it in Domain specific algorithms - Terrain analysis and geomorphometry). I used the 2. Degree Polynom (Zevenbergen & Thorne), which is the default. A visual check shows that the general location of slopes seems to fit (I compared it to Google Earth).
Now my problem is: I have no clue about the unit of the output. The pixels at the steepest slopes have values around 0.3.... I have never been to that area, but it is located in Southern Germany, in an area that is usually quite hilly. So I strongly doubt that the slope is only 0.3° in the steepest area. I have the assumption that it is just 30°, but I would like to check somewhere to be absolutely sure how to interpret the result (since it could also be percentage values). I find a lot of information about what the tool does, but never any site where the units of the output are clearly stated.
Does anybody know how I can find out the unit of this output?