func (cs *CoordinateSystem) GeodeticToGeocentric(plh *globals.PLH) *globals.XYZ {
xyz := &globals.XYZ{}
if _, ok := cs.FloatParams["e2"]; !ok {
cs.SetGeocentricParameters()
}
e2 := cs.FloatParams["e2"]
a := cs.FloatParams["a_orig"]
if plh.Phi < -globals.PI_OVER_2 && plh.Phi > -1.001*globals.PI_OVER_2 {
plh.Phi = -globals.PI_OVER_2
} else if plh.Phi > globals.PI_OVER_2 && plh.Phi < 1.001*globals.PI_OVER_2 {
plh.Phi = globals.PI_OVER_2
}
if plh.Lam > globals.PI {
plh.Lam = plh.Lam - 2*globals.PI
}
sin_lat := math.Sin(plh.Phi)
cos_lat := math.Cos(plh.Phi)
sin2_lat := sin_lat * sin_lat
rn := a / (math.Sqrt(1.0 - e2*sin2_lat))
xyz.X = (rn + plh.Height) * cos_lat * math.Cos(plh.Lam)
xyz.Y = (rn + plh.Height) * cos_lat * math.Sin(plh.Lam)
xyz.Z = ((rn * (1 - e2)) + plh.Height) * sin_lat
return xyz
}
func StereaForward(params map[string]float64, plh *globals.PLH) *globals.XYZ { // lat, lon float64) (x, y float64) {
xyz := &globals.XYZ{}
// Gauss
// local_phi := lat * DEG_TO_RAD
// local_lam := lon * DEG_TO_RAD
plh.Phi = 2.0*math.Atan(params["K"]*math.Pow(math.Tan(0.5*plh.Phi+globals.PI_OVER_4), params["C"])*srat(params["e"]*math.Sin(plh.Phi), params["ratexp"])) - globals.PI_OVER_2
plh.Lam = params["C"] * plh.Lam
// Sterea
sinc := math.Sin(plh.Phi)
cosc := math.Cos(plh.Phi)
cosl := math.Cos(plh.Lam)
k := params["k"] * params["2R"] / (1.0 + params["sinc0"]*sinc + params["cosc0"]*cosc*cosl)
xyz.X = k * cosc * math.Sin(plh.Lam)
xyz.Y = k * (params["cosc0"]*sinc - params["sinc0"]*cosc*cosl)
return xyz
}