I'm trying to georeference some maps of Namibia and am having trouble. The projection stated on the map is the "Gauss Conform Central Meridian 15deg E. Bessel's Spheroid". I've tried using South African CRS : HBK_NO_15 and CAPE_NO_15 on the assumption that perhaps the "NO_15" refers to the central meridian. These are the closest I could find to the projection listed on the map.
Is this the right coordinate reference system, and if not does anyone have any idea what is?
I have also asked a related question as Upside down result when I use QGis to georeference 1977 S. African Land Survey Maps of Namibia
Answer
_NO_15 means North orientated. The CRS mostly used in South Africa and Namibia are South orientated, marked Lo. Positive Locoordinates go to the West and South.
I suggest Schwarzeck / Lo22/15 for your data, since HBK and CAPE use a different ellipsoid that is used only in South Africa.
Looking at your sample map, I see projected coordinates only as small map ticks at the border. So I suggest to better georeference using the degree coordinates of the corners (and maybe more points on the edges) and EPSG:4293 Schwarzeck. That CRS uses the same ellipsoid as Lo22/15. Note that South latitudes must be entered negative.
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