cdm/src/main/java/ucar/unidata/geoloc/projection/Stereographic.java
static public Stereographic factory(double latt, double lont, double latTrue) {
    double scale = (1.0 + Math.sin(Math.toRadians(latTrue))) / 2.0;
    return new Stereographic(latt, lont, scale);
  }
static public Stereographic factory(double latt, double lont, double latTrue) {
    double scale = (1.0 + Math.sin(Math.toRadians(latTrue))) / 2.0;
    return new Stereographic(latt, lont, scale);
  }
Construct a Stereographic Projection using latitude of true scale and calculating scale factor.
<p> Since the scale factor at lat = k = 2*k0/(1+sin(lat))  [Snyder,Working Manual p157]
then to make scale = 1 at lat, set k0 = (1+sin(lat))/2

@param latt    tangent point of projection, also origin of projection coord system
@param lont    tangent point of projection, also origin of projection coord system
@param latTrue latitude of true scale in degrees north; latitude where scale factor = 1.0
@return Stereographic projection