def toNed(distance, bearing, elevation, Ned=Ned, name=NN):
'''Create an NED vector from distance, bearing and elevation
(in local coordinate system).
@arg distance: NED vector length (C{meter}).
@arg bearing: NED vector bearing (compass C{degrees360}).
@arg elevation: NED vector elevation from local coordinate
frame horizontal (C{degrees}).
@kwarg Ned: Optional class to return the NED (L{Ned}) or
C{None}.
@kwarg name: Optional name (C{str}).
@return: An NED vector equivalent to this B{C{distance}},
B{C{bearing}} and B{C{elevation}} (L{Ned}) or
if B{C{Ned=None}}, an L{Ned3Tuple}C{(north, east,
down)}.
@raise ValueError: Invalid B{C{distance}}, B{C{bearing}}
or B{C{elevation}}.
@JSname: I{fromDistanceBearingElevation}.
'''
d = Distance(distance)
sb, cb, se, ce = sincos2d(Bearing(bearing), Height(elevation=elevation))
n = cb * d * ce
e = sb * d * ce
d *= se
r = Ned3Tuple(n, e, -d) if Ned is None else \
Ned(n, e, -d)
return _xnamed(r, name)
def heightOf(angle, distance, radius=R_M):
'''Determine the height above the (spherical) earth after
traveling along a straight line at a given tilt.
@arg angle: Tilt angle above horizontal (C{degrees}).
@arg distance: Distance along the line (C{meter} or same units as
B{C{radius}}).
@kwarg radius: Optional mean earth radius (C{meter}).
@return: Height (C{meter}, same units as B{C{distance}} and B{C{radius}}).
@raise ValueError: Invalid B{C{angle}}, B{C{distance}} or B{C{radius}}.
@see: U{MultiDop geog_lib.GeogBeamHt<https://GitHub.com/NASA/MultiDop>}
(U{Shapiro et al. 2009, JTECH
<https://Journals.AMetSoc.org/doi/abs/10.1175/2009JTECHA1256.1>}
and U{Potvin et al. 2012, JTECH
<https://Journals.AMetSoc.org/doi/abs/10.1175/JTECH-D-11-00019.1>}).
'''
r = h = Radius(radius)
d = abs(Distance(distance))
if d > h:
d, h = h, d
if d > EPS:
d = d / h # PyChecker chokes on ... /= ...
s = sin(Phi_(angle, name='angle', clip=180))
s = fsum_(1, 2 * s * d, d**2)
if s > 0:
return h * sqrt(s) - r
raise InvalidError(angle=angle, distance=distance, radius=radius)
def _angular(distance, radius): # PYCHOK for export
'''(INTERNAL) Return the angular distance in radians.
@raise ValueError: Invalid B{C{distance}} or B{C{radius}}.
'''
return Distance(distance) / Radius_(radius)