# http://pyrocko.org - GPLv3
#
# The Pyrocko Developers, 21st Century
# ---|P------/S----------~Lg----------
'''
Representation of a geographical location, base class for stations, events,
etc.
'''
import numpy as num
import math
from pyrocko import orthodrome
from pyrocko.guts import Object, Float
guts_prefix = 'pf'
d2r = math.pi / 180.
r2d = 1.0 / d2r
km = 1000.
def latlondepth_to_cartesian(lat, lon, depth):
return orthodrome.geodetic_to_ecef(lat, lon, -depth)
[docs]class Location(Object):
'''
Geographical location.
The location is given by a reference point at the earth's surface
(:py:attr:`lat`, :py:attr:`lon`, :py:attr:`elevation`) and a cartesian
offset from this point (:py:attr:`north_shift`, :py:attr:`east_shift`,
:py:attr:`depth`). The offset corrected lat/lon coordinates of the location
can be accessed though the :py:attr:`effective_latlon`,
:py:attr:`effective_lat`, and :py:attr:`effective_lon` properties.
'''
lat = Float.T(
default=0.0,
optional=True,
help='Latitude of reference point [deg].')
lon = Float.T(
default=0.0,
optional=True,
help='Longitude of reference point [deg].')
north_shift = Float.T(
default=0.,
optional=True,
help='Northward cartesian offset from reference point [m].')
east_shift = Float.T(
default=0.,
optional=True,
help='Eastward cartesian offset from reference point [m].')
elevation = Float.T(
default=0.0,
optional=True,
help='Surface elevation, above sea level [m].')
depth = Float.T(
default=0.0,
help='Depth, below surface [m].')
def __init__(self, **kwargs):
Object.__init__(self, **kwargs)
self._latlon = None
def __setattr__(self, name, value):
if name in ('lat', 'lon', 'north_shift', 'east_shift'):
self.__dict__['_latlon'] = None
Object.__setattr__(self, name, value)
@property
def effective_latlon(self):
'''
Property holding the offset-corrected lat/lon pair of the location.
'''
if self._latlon is None:
if self.north_shift == 0.0 and self.east_shift == 0.0:
self._latlon = self.lat, self.lon
else:
self._latlon = tuple(float(x) for x in orthodrome.ne_to_latlon(
self.lat, self.lon, self.north_shift, self.east_shift))
return self._latlon
@property
def effective_lat(self):
'''
Property holding the offset-corrected latitude of the location.
'''
return self.effective_latlon[0]
@property
def effective_lon(self):
'''
Property holding the offset-corrected longitude of the location.
'''
return self.effective_latlon[1]
[docs] def same_origin(self, other):
'''
Check whether other location object has the same reference location.
'''
return self.lat == other.lat and self.lon == other.lon
[docs] def distance_to(self, other):
'''
Compute surface distance [m] to other location object.
'''
if self.same_origin(other):
other_north_shift, other_east_shift = get_offset(other)
return math.sqrt((self.north_shift - other_north_shift)**2 +
(self.east_shift - other_east_shift)**2)
else:
slat, slon = self.effective_latlon
rlat, rlon = get_effective_latlon(other)
return float(orthodrome.distance_accurate50m_numpy(
slat, slon, rlat, rlon)[0])
[docs] def distance_3d_to(self, other):
'''
Compute 3D distance [m] to other location object.
All coordinates are transformed to cartesian coordinates if necessary
then distance is:
.. math::
\\Delta = \\sqrt{\\Delta {\\bf x}^2 + \\Delta {\\bf y}^2 + \
\\Delta {\\bf z}^2}
'''
if self.same_origin(other):
other_north_shift, other_east_shift = get_offset(other)
return math.sqrt((self.north_shift - other_north_shift)**2 +
(self.east_shift - other_east_shift)**2 +
(self.depth - other.depth)**2)
else:
slat, slon = self.effective_latlon
rlat, rlon = get_effective_latlon(other)
sx, sy, sz = latlondepth_to_cartesian(slat, slon, self.depth)
rx, ry, rz = latlondepth_to_cartesian(rlat, rlon, other.depth)
return math.sqrt((sx-rx)**2 + (sy-ry)**2 + (sz-rz)**2)
def offset_to(self, other):
if self.same_origin(other):
other_north_shift, other_east_shift = get_offset(other)
return (
other_north_shift - self.north_shift,
other_east_shift - self.east_shift)
else:
azi, bazi = self.azibazi_to(other)
dist = self.distance_to(other)
return dist*math.cos(azi*d2r), dist*math.sin(azi*d2r)
[docs] def azibazi_to(self, other):
'''
Compute azimuth and backazimuth to and from other location object.
'''
if self.same_origin(other):
other_north_shift, other_east_shift = get_offset(other)
azi = r2d * math.atan2(other_east_shift - self.east_shift,
other_north_shift - self.north_shift)
bazi = azi + 180.
else:
slat, slon = self.effective_latlon
rlat, rlon = get_effective_latlon(other)
azi, bazi = orthodrome.azibazi(slat, slon, rlat, rlon)
return float(azi), float(bazi)
def set_origin(self, lat, lon):
lat = float(lat)
lon = float(lon)
elat, elon = self.effective_latlon
n, e = orthodrome.latlon_to_ne(lat, lon, elat, elon)
self.lat = lat
self.lon = lon
self.north_shift = float(n)
self.east_shift = float(e)
self._latlon = elat, elon # unchanged
@property
def coords5(self):
return num.array([
self.lat, self.lon, self.north_shift, self.east_shift, self.depth])
def get_offset(obj):
try:
return obj.north_shift, obj.east_shift
except AttributeError:
return 0.0, 0.0
def get_effective_latlon(obj):
try:
return obj.effective_latlon
except AttributeError:
return obj.lat, obj.lon
