# File lib/jpmobile/datum_conv.rb, line 15
  def self.blh2xyz(b_deg,l_deg,he,datum)
    a = datum[0].to_f
    f = 1.0/datum[1]
    b = b_deg * Deg2Rad
    l = l_deg * Deg2Rad

    e2 = f * (2 - f)
    n = a / Math.sqrt(1 - e2 * Math.sin(b)**2 )

    x = (n+he)*Math.cos(b)*Math.cos(l)
    y = (n+he)*Math.cos(b)*Math.sin(l)
    z = (n*(1-e2)+he)*Math.sin(b)
    return x,y,z
  end