Coverage for pygeodesy/datums.py: 97%
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2# -*- coding: utf-8 -*-
4u'''Datums and transformations thereof.
6Classes L{Datum} and L{Transform} and registries L{Datums} and L{Transforms}, respectively.
8Pure Python implementation of geodesy tools for ellipsoidal earth models, including datums
9and ellipsoid parameters for different geographic coordinate systems and methods for
10converting between them and to cartesian coordinates. Transcoded from JavaScript originals by
11I{(C) Chris Veness 2005-2016} and published under the same MIT Licence**, see U{latlon-ellipsoidal.js
12<https://www.Movable-Type.co.UK/scripts/geodesy/docs/latlon-ellipsoidal.js.html>}.
14Historical geodetic datums: a latitude/longitude point defines a geographic location on or
15above/below the earth’s surface, measured in degrees from the equator, from the International
16Reference Meridian, in meters above the ellipsoid and based on a given datum. The datum in turn
17is based on a reference ellipsoid and tied to geodetic survey reference points.
19Modern geodesy is generally based on the WGS84 datum (as used for instance by GPS systems),
20but previously various reference ellipsoids and datum references were used.
22The UK Ordnance Survey National Grid References are still based on the otherwise historical
23OSGB36 datum, q.v. U{"A Guide to Coordinate Systems in Great Britain", Section 6
24<https://www.OrdnanceSurvey.co.UK/docs/support/guide-coordinate-systems-great-britain.pdf>}.
26@var Datums.BD72: Datum(name='BD72', ellipsoid=Ellipsoids.Intl1924, transform=Transforms.BD72)
27@var Datums.DHDN: Datum(name='DHDN', ellipsoid=Ellipsoids.Bessel1841, transform=Transforms.DHDN)
28@var Datums.ED50: Datum(name='ED50', ellipsoid=Ellipsoids.Intl1924, transform=Transforms.ED50)
29@var Datums.GDA2020: Datum(name='GDA2020', ellipsoid=Ellipsoids.GRS80, transform=Transforms.WGS84)
30@var Datums.GRS80: Datum(name='GRS80', ellipsoid=Ellipsoids.GRS80, transform=Transforms.WGS84)
31@var Datums.Irl1975: Datum(name='Irl1975', ellipsoid=Ellipsoids.AiryModified, transform=Transforms.Irl1975)
32@var Datums.Krassovski1940: Datum(name='Krassovski1940', ellipsoid=Ellipsoids.Krassovski1940, transform=Transforms.Krassovski1940)
33@var Datums.Krassowsky1940: Datum(name='Krassowsky1940', ellipsoid=Ellipsoids.Krassowsky1940, transform=Transforms.Krassowsky1940)
34@var Datums.MGI: Datum(name='MGI', ellipsoid=Ellipsoids.Bessel1841, transform=Transforms.MGI)
35@var Datums.NAD27: Datum(name='NAD27', ellipsoid=Ellipsoids.Clarke1866, transform=Transforms.NAD27)
36@var Datums.NAD83: Datum(name='NAD83', ellipsoid=Ellipsoids.GRS80, transform=Transforms.NAD83)
37@var Datums.NTF: Datum(name='NTF', ellipsoid=Ellipsoids.Clarke1880IGN, transform=Transforms.NTF)
38@var Datums.OSGB36: Datum(name='OSGB36', ellipsoid=Ellipsoids.Airy1830, transform=Transforms.OSGB36)
39@var Datums.Potsdam: Datum(name='Potsdam', ellipsoid=Ellipsoids.Bessel1841, transform=Transforms.Bessel1841)
40@var Datums.Sphere: Datum(name='Sphere', ellipsoid=Ellipsoids.Sphere, transform=Transforms.WGS84)
41@var Datums.TokyoJapan: Datum(name='TokyoJapan', ellipsoid=Ellipsoids.Bessel1841, transform=Transforms.TokyoJapan)
42@var Datums.WGS72: Datum(name='WGS72', ellipsoid=Ellipsoids.WGS72, transform=Transforms.WGS72)
43@var Datums.WGS84: Datum(name='WGS84', ellipsoid=Ellipsoids.WGS84, transform=Transforms.WGS84)
45@var Transforms.BD72: Transform(name='BD72', tx=106.86863, ty=-52.29778, tz=103.72389, rx=-0, ry=-0, rz=-0.00001, s=1.2727, s1=1, sx=-0.33657, sy=-0.45696, sz=-1.84218)
46@var Transforms.Bessel1841: Transform(name='Bessel1841', tx=-582, ty=-105, tz=-414, rx=-0.00001, ry=-0, rz=0.00001, s=-8.3, s1=0.99999, sx=-1.04, sy=-0.35, sz=3.08)
47@var Transforms.Clarke1866: Transform(name='Clarke1866', tx=8, ty=-160, tz=-176, rx=0, ry=0, rz=0, s=0, s1=1, sx=0, sy=0, sz=0)
48@var Transforms.DHDN: Transform(name='DHDN', tx=-591.28, ty=-81.35, tz=-396.39, rx=0.00001, ry=-0, rz=-0.00001, s=-9.82, s1=0.99999, sx=1.477, sy=-0.0736, sz=-1.458)
49@var Transforms.ED50: Transform(name='ED50', tx=89.5, ty=93.8, tz=123.1, rx=0, ry=0, rz=0, s=-1.2, s1=1, sx=0, sy=0, sz=0.156)
50@var Transforms.Identity: Transform(name='Identity', tx=0, ty=0, tz=0, rx=0, ry=0, rz=0, s=0, s1=1, sx=0, sy=0, sz=0)
51@var Transforms.Irl1965: Transform(name='Irl1965', tx=-482.53, ty=130.596, tz=-564.557, rx=0.00001, ry=0, rz=0, s=-8.15, s1=0.99999, sx=1.042, sy=0.214, sz=0.631)
52@var Transforms.Irl1975: Transform(name='Irl1975', tx=-482.53, ty=130.596, tz=-564.557, rx=-0.00001, ry=-0, rz=-0, s=-1.1, s1=1, sx=-1.042, sy=-0.214, sz=-0.631)
53@var Transforms.Krassovski1940: Transform(name='Krassovski1940', tx=-24, ty=123, tz=94, rx=-0, ry=0, rz=0, s=-2.423, s1=1, sx=-0.02, sy=0.26, sz=0.13)
54@var Transforms.Krassowsky1940: Transform(name='Krassowsky1940', tx=-24, ty=123, tz=94, rx=-0, ry=0, rz=0, s=-2.423, s1=1, sx=-0.02, sy=0.26, sz=0.13)
55@var Transforms.MGI: Transform(name='MGI', tx=-577.326, ty=-90.129, tz=-463.92, rx=0.00002, ry=0.00001, rz=0.00003, s=-2.423, s1=1, sx=5.137, sy=1.474, sz=5.297)
56@var Transforms.NAD27: Transform(name='NAD27', tx=8, ty=-160, tz=-176, rx=0, ry=0, rz=0, s=0, s1=1, sx=0, sy=0, sz=0)
57@var Transforms.NAD83: Transform(name='NAD83', tx=1.004, ty=-1.91, tz=-0.515, rx=0, ry=0, rz=0, s=-0.0015, s1=1, sx=0.0267, sy=0.00034, sz=0.011)
58@var Transforms.NTF: Transform(name='NTF', tx=-168, ty=-60, tz=320, rx=0, ry=0, rz=0, s=0, s1=1, sx=0, sy=0, sz=0)
59@var Transforms.OSGB36: Transform(name='OSGB36', tx=-446.448, ty=125.157, tz=-542.06, rx=-0, ry=-0, rz=-0, s=20.4894, s1=1.00002, sx=-0.1502, sy=-0.247, sz=-0.8421)
60@var Transforms.TokyoJapan: Transform(name='TokyoJapan', tx=148, ty=-507, tz=-685, rx=0, ry=0, rz=0, s=0, s1=1, sx=0, sy=0, sz=0)
61@var Transforms.WGS72: Transform(name='WGS72', tx=0, ty=0, tz=-4.5, rx=0, ry=0, rz=0, s=-0.22, s1=1, sx=0, sy=0, sz=0.554)
62@var Transforms.WGS84: Transform(name='WGS84', tx=0, ty=0, tz=0, rx=0, ry=0, rz=0, s=0, s1=1, sx=0, sy=0, sz=0)
63'''
64# make sure int/int division yields float quotient, see .basics
65from __future__ import division as _; del _ # PYCHOK semicolon
67from pygeodesy.basics import islistuple, isscalar, map2, neg, _xinstanceof
68from pygeodesy.constants import R_M, _float as _F, _0_0, _0_26, _1_0, _2_0, _8_0, _3600_0
69from pygeodesy.ellipsoids import a_f2Tuple, Ellipsoid, Ellipsoid2, Ellipsoids, Vector3Tuple
70from pygeodesy.errors import _IsnotError, _xattr
71from pygeodesy.fmath import fdot, fmean, Fmt
72from pygeodesy.interns import NN, _a_, _Airy1830_, _AiryModified_, _Bessel1841_, _cartesian_, \
73 _Clarke1866_, _Clarke1880IGN_, _COMMASPACE_, _DOT_, _earth_, \
74 _ellipsoid_, _ellipsoidal_, _GRS80_, _Intl1924_, _Krassovski1940_, \
75 _Krassowsky1940_, _NAD27_, _NAD83_, _s_, _Sphere_, _spherical_, \
76 _sx_, _sy_, _sz_, _transform_, _tx_, _ty_, _tz_, _UNDER_, \
77 _WGS72_, _WGS84_, _UNDER
78from pygeodesy.lazily import _ALL_LAZY, _ALL_MODS as _MODS
79from pygeodesy.named import _NamedEnum, _NamedEnumItem, \
80 _lazyNamedEnumItem as _lazy, Property_RO
81# from pygeodesy.namedTuples import Vector3Tuple # from .ellipsoids
82# from pygeodesy.props import Property_RO # from .named
83# from pygeodesy.streprs import Fmt # from .fmath
84from pygeodesy.units import radians, Radius_
86# from math import radians # from .units
88__all__ = _ALL_LAZY.datums
89__version__ = '23.06.12'
91_a_ellipsoid_ = _UNDER_(_a_, _ellipsoid_)
92_BD72_ = 'BD72'
93_DHDN_ = 'DHDN'
94_ED50_ = 'ED50'
95_GDA2020_ = 'GDA2020'
96_Identity_ = 'Identity'
97_Inverse_ = 'Inverse'
98_Irl1965_ = 'Irl1965'
99_Irl1975_ = 'Irl1975'
100_MGI_ = 'MGI'
101_NTF_ = 'NTF'
102_OSGB36_ = 'OSGB36'
103_Potsdam_ = 'Potsdam'
104_TokyoJapan_ = 'TokyoJapan'
106_r_s1 = radians(1 / _3600_0) # 1 degree second to radians
109def _r_s2(s_):
110 '''(INTERNAL) rotation in C{radians} and C{degree seconds}.
111 '''
112 return _F(_r_s1 * s_), s_
115class Transform(_NamedEnumItem):
116 '''Helmert transformation.
118 @see: L{Helmert7Tuple}.
119 '''
120 tx = _0_0 # x translation (C{meter})
121 ty = _0_0 # y translation (C{meter})
122 tz = _0_0 # z translation (C{meter})
124 rx = _0_0 # x rotation (C{radians})
125 ry = _0_0 # y rotation (C{radians})
126 rz = _0_0 # z rotation (C{radians})
128 s = _0_0 # scale ppm (C{float})
129 s1 = _1_0 # scale + 1 (C{float})
131 sx = _0_0 # x rotation (degree seconds)
132 sy = _0_0 # y rotation (degree seconds)
133 sz = _0_0 # z rotation (degree seconds)
135 def __init__(self, name=NN, tx=0, ty=0, tz=0,
136 sx=0, sy=0, sz=0, s=0):
137 '''New L{Transform}.
139 @kwarg name: Optional, unique name (C{str}).
140 @kwarg tx: Optional X translation (C{meter}).
141 @kwarg ty: Optional Y translation (C{meter}).
142 @kwarg tz: Optional Z translation (C{meter}).
143 @kwarg s: Optional scale (C{float}), ppm.
144 @kwarg sx: Optional X rotation (C{degree seconds}).
145 @kwarg sy: Optional Y rotation (C{degree seconds}).
146 @kwarg sz: Optional Z rotation (C{degree seconds}).
148 @raise NameError: Transform with that B{C{name}} already exists.
149 '''
150 if tx:
151 self.tx = tx
152 if ty:
153 self.ty = ty
154 if tz:
155 self.tz = tz
156 if sx: # secs to rads
157 self.rx, self.sx = _r_s2(sx)
158 if sy:
159 self.ry, self.sy = _r_s2(sy)
160 if sz:
161 self.rz, self.sz = _r_s2(sz)
162 if s:
163 self.s = s
164 self.s1 = _F(s * 1e-6 + _1_0) # normalize ppm to (s + 1)
166 self._register(Transforms, name)
168 def __eq__(self, other):
169 '''Compare this and an other transform.
171 @arg other: The other transform (L{Transform}).
173 @return: C{True} if equal, C{False} otherwise.
174 '''
175 return self is other or (isinstance(other, Transform)
176 and self.tx == other.tx
177 and self.ty == other.ty
178 and self.tz == other.tz
179 and self.rx == other.rx
180 and self.ry == other.ry
181 and self.rz == other.rz
182 and self.s == other.s)
184 def __matmul__(self, other): # PYCHOK Python 3.5+
185 '''Helmert-transform a cartesian B{C{other}}.
187 @raise TypeError: Invalid B{C{other}}.
188 '''
189 try: # only CartesianBase
190 return other.toTransform(self)
191 except AttributeError:
192 pass
193 raise _IsnotError(_cartesian_, other=other)
195 def inverse(self, name=NN):
196 '''Return the inverse of this transform.
198 @kwarg name: Optional, unique name (C{str}).
200 @return: Inverse (Transform).
202 @raise NameError: Transform with that B{C{name}} already exists.
203 '''
204 return Transform(name=name or (self.name + _Inverse_),
205 tx=-self.tx, ty=-self.ty, tz=-self.tz,
206 sx=-self.sx, sy=-self.sy, sz=-self.sz, s=-self.s)
208 def toStr(self, prec=5, name=NN, **unused): # PYCHOK expected
209 '''Return this transform as a string.
211 @kwarg prec: Number of (decimal) digits, unstripped (C{int}).
212 @kwarg name: Override name (C{str}) or C{None} to exclude
213 this transform's name.
215 @return: Transform attributes (C{str}).
216 '''
217 return self._instr(name, prec, _tx_, _ty_, _tz_,
218 'rx', 'ry', 'rz', _s_, 's1',
219 _sx_, _sy_, _sz_)
221 def transform(self, x, y, z, inverse=False):
222 '''Transform a (geocentric) Cartesian point, forward or inverse.
224 @arg x: X coordinate (C{meter}).
225 @arg y: Y coordinate (C{meter}).
226 @arg z: Z coordinate (C{meter}).
227 @kwarg inverse: Optional direction, forward or inverse (C{bool}).
229 @return: A L{Vector3Tuple}C{(x, y, z)}, transformed.
230 '''
231 xyz1 = x, y, z, _1_0
232 s1 = self.s1
233 if inverse:
234 xyz1 = map2(neg, xyz1)
235 s1 -= _2_0 # = -(1 - s * 1e-6)) = -(1 - (s1 - 1)) = -(2 - s1)
236 # x', y', z' = (x * .s1 - y * .rz + z * .ry + .tx,
237 # x * .rz + y * .s1 - z * .rx + .ty,
238 # -x * .ry + y * .rx + z * .s1 + .tz)
239 return Vector3Tuple(fdot(xyz1, s1, -self.rz, self.ry, self.tx),
240 fdot(xyz1, self.rz, s1, -self.rx, self.ty),
241 fdot(xyz1, -self.ry, self.rx, s1, self.tz),
242 name=self.name)
245class Transforms(_NamedEnum):
246 '''(INTERNAL) L{Transform} registry, I{must} be a sub-class
247 to accommodate the L{_LazyNamedEnumItem} properties.
248 '''
249 def _Lazy(self, **name_tx_ty_tz_sx_sy_sz_s):
250 '''(INTERNAL) Instantiate the C{Transform}.
251 '''
252 return Transform(**name_tx_ty_tz_sx_sy_sz_s)
254Transforms = Transforms(Transform) # PYCHOK singleton
255'''Some pre-defined L{Transform}s, all I{lazily} instantiated.'''
256# <https://WikiPedia.org/wiki/Helmert_transformation> from WGS84
257Transforms._assert(
258 BD72 = _lazy(_BD72_, tx=_F(106.868628), ty=_F(-52.297783), tz=_F(103.723893),
259 # <https://www.NGI.Be/FR/FR4-4.shtm> ETRS89 == WG84
260 # <https://EPSG.org/transformation_15929/BD72-to-WGS-84-3.html>
261 sx=_F(-0.33657), sy=_F( -0.456955), sz=_F( -1.84218),
262 s=_F( 1.2727)),
263 Bessel1841 = _lazy(_Bessel1841_, tx=_F(-582.0), ty=_F(-105.0), tz=_F(-414.0),
264 sx=_F( -1.04), sy=_F( -0.35), sz=_F( 3.08),
265 s=_F( -8.3)),
266 Clarke1866 = _lazy(_Clarke1866_, tx=_F(8), ty=_F(-160), tz=_F(-176)),
267 DHDN = _lazy(_DHDN_, tx=_F(-591.28), ty=_F(-81.35), tz=_F(-396.39),
268 sx=_F( 1.477), sy=_F( -0.0736), sz=_F( -1.458),
269 s=_F( -9.82)), # Germany
270 ED50 = _lazy(_ED50_, tx=_F(89.5), ty=_F(93.8), tz=_F(123.1),
271 # <https://GeoNet.ESRI.com/thread/36583> sz=_F(-0.156)
272 # <https://GitHub.com/ChrisVeness/geodesy/blob/master/latlon-ellipsoidal.js>
273 # <https://www.Gov.UK/guidance/oil-and-gas-petroleum-operations-notices#pon-4>
274 sz=_F( 0.156), s=_F(-1.2)),
275 Identity = _lazy(_Identity_),
276 Irl1965 = _lazy(_Irl1965_, tx=_F(-482.530), ty=_F(130.596), tz=_F(-564.557),
277 sx=_F( 1.042), sy=_F( 0.214), sz=_F( 0.631),
278 s=_F( -8.15)),
279 Irl1975 = _lazy(_Irl1975_, tx=_F(-482.530), ty=_F(130.596), tz=_F(-564.557),
280 # XXX rotation signs may be opposite, to be checked
281 sx=_F( -1.042), sy=_F( -0.214), sz=_F( -0.631),
282 s=_F( -1.1)),
283 Krassovski1940 = _lazy(_Krassovski1940_, tx=_F(-24.0), ty=_F(123.0), tz=_F(94.0),
284 sx=_F( -0.02), sy= _0_26, sz=_F( 0.13),
285 s=_F( -2.423)), # spelling
286 Krassowsky1940 = _lazy(_Krassowsky1940_, tx=_F(-24.0), ty=_F(123.0), tz=_F(94.0),
287 sx=_F( -0.02), sy= _0_26, sz=_F( 0.13),
288 s=_F( -2.423)), # spelling
289 MGI = _lazy(_MGI_, tx=_F(-577.326), ty=_F(-90.129), tz=_F(-463.920),
290 sx=_F( 5.137), sy=_F( 1.474), sz=_F( 5.297),
291 s=_F( -2.423)), # Austria
292 NAD27 = _lazy(_NAD27_, tx=_8_0, ty=_F(-160), tz=_F(-176)),
293 NAD83 = _lazy(_NAD83_, tx=_F( 1.004), ty=_F(-1.910), tz=_F(-0.515),
294 sx=_F( 0.0267), sy=_F( 0.00034), sz=_F( 0.011),
295 s=_F(-0.0015)),
296 NTF = _lazy(_NTF_, tx=_F(-168), ty=_F(-60), tz=_F(320)), # XXX verify
297 OSGB36 = _lazy(_OSGB36_, tx=_F(-446.448), ty=_F(125.157), tz=_F(-542.060),
298 sx=_F( -0.1502), sy=_F( -0.2470), sz=_F( -0.8421),
299 s=_F( 20.4894)),
300 TokyoJapan = _lazy(_TokyoJapan_, tx=_F(148), ty=_F(-507), tz=_F(-685)),
301 WGS72 = _lazy(_WGS72_, tz=_F(-4.5), sz=_F(0.554), s=_F(-0.22)),
302 WGS84 = _lazy(_WGS84_), # unity
303)
306class Datum(_NamedEnumItem):
307 '''Ellipsoid and transform parameters for an earth model.
308 '''
309 _ellipsoid = Ellipsoids.WGS84 # default ellipsoid (L{Ellipsoid}, L{Ellipsoid2})
310 _transform = Transforms.WGS84 # default transform (L{Transform})
312 def __init__(self, ellipsoid, transform=None, name=NN):
313 '''New L{Datum}.
315 @arg ellipsoid: The ellipsoid (L{Ellipsoid} or L{Ellipsoid2}).
316 @kwarg transform: Optional transform (L{Transform}).
317 @kwarg name: Optional, unique name (C{str}).
319 @raise NameError: Datum with that B{C{name}} already exists.
321 @raise TypeError: If B{C{ellipsoid}} is not an L{Ellipsoid}
322 nor L{Ellipsoid2} or B{C{transform}} is
323 not a L{Transform}.
324 '''
325 self._ellipsoid = ellipsoid or Datum._ellipsoid
326 _xinstanceof(Ellipsoid, ellipsoid=self.ellipsoid)
328 self._transform = transform or Datum._transform
329 _xinstanceof(Transform, transform=self.transform)
331 self._register(Datums, name or self.transform.name or self.ellipsoid.name)
333 def __eq__(self, other):
334 '''Compare this and an other datum.
336 @arg other: The other datum (L{Datum}).
338 @return: C{True} if equal, C{False} otherwise.
339 '''
340 return self is other or (isinstance(other, Datum) and
341 self.ellipsoid == other.ellipsoid and
342 self.transform == other.transform)
344 def __matmul__(self, other): # PYCHOK Python 3.5+
345 '''Convert cartesian or ellipsoidal B{C{other}} to this datum.
347 @raise TypeError: Invalid B{C{other}}.
348 '''
349 try: # only CartesianBase and EllipsoidalLatLonBase
350 return other.toDatum(self)
351 except AttributeError:
352 pass
353 raise _IsnotError(_cartesian_, _ellipsoidal_, other=other)
355 def ecef(self, Ecef=None):
356 '''Return U{ECEF<https://WikiPedia.org/wiki/ECEF>} converter.
358 @kwarg Ecef: ECEF class to use, default L{EcefKarney}.
360 @return: An ECEF converter for this C{datum}.
362 @raise TypeError: Invalid B{C{Ecef}}.
364 @see: Module L{pygeodesy.ecef}.
365 '''
366 return _MODS.ecef._4Ecef(self, Ecef)
368 @Property_RO
369 def ellipsoid(self):
370 '''Get this datum's ellipsoid (L{Ellipsoid} or L{Ellipsoid2}).
371 '''
372 return self._ellipsoid
374 @Property_RO
375 def exactTM(self):
376 '''Get the C{ExactTM} projection (L{ExactTransverseMercator}).
377 '''
378 return _MODS.etm.ExactTransverseMercator(datum=self)
380 @Property_RO
381 def isEllipsoidal(self):
382 '''Check whether this datum is ellipsoidal (C{bool}).
383 '''
384 return self._ellipsoid.isEllipsoidal
386 @Property_RO
387 def isOblate(self):
388 '''Check whether this datum's ellipsoidal is I{oblate} (C{bool}).
389 '''
390 return self._ellipsoid.isOblate
392 @Property_RO
393 def isProlate(self):
394 '''Check whether this datum's ellipsoidal is I{prolate} (C{bool}).
395 '''
396 return self._ellipsoid.isProlate
398 @Property_RO
399 def isSpherical(self):
400 '''Check whether this datum is (near-)spherical (C{bool}).
401 '''
402 return self._ellipsoid.isSpherical
404 def toStr(self, sep=_COMMASPACE_, name=NN, **unused): # PYCHOK expected
405 '''Return this datum as a string.
407 @kwarg sep: Separator to join (C{str}).
408 @kwarg name: Override name (C{str}) or C{None} to exclude
409 this datum's name.
411 @return: Datum attributes (C{str}).
412 '''
413 t = [] if name is None else \
414 [Fmt.EQUAL(name=repr(name or self.named))]
415 for a in (_ellipsoid_, _transform_):
416 v = getattr(self, a)
417 t.append(NN(Fmt.EQUAL(a, v.classname), _s_, _DOT_, v.name))
418 return sep.join(t)
420 @Property_RO
421 def transform(self):
422 '''Get this datum's transform (L{Transform}).
423 '''
424 return self._transform
427def _En2(earth, name):
428 '''(INTERNAL) Helper for C{_ellipsoid} and C{_ellipsoidal_datum}.
429 '''
430 if isinstance(earth, (Ellipsoid, Ellipsoid2)):
431 E = earth
432 n = _UNDER(name or E.name)
433 elif isinstance(earth, Datum):
434 E = earth.ellipsoid
435 n = _UNDER(name or earth.name)
436 elif isinstance(earth, a_f2Tuple):
437 n = _UNDER(name or earth.name)
438 E = Ellipsoid(earth.a, earth.b, name=n)
439 elif islistuple(earth, minum=2):
440 a, f = earth[:2]
441 n = _UNDER(name or _xattr(earth, name=NN))
442 E = Ellipsoid(a, f=f, name=n)
443 else:
444 E, n = None, NN
445 return E, n
448def _a_ellipsoid(a_ellipsoid, f=None, name=NN, raiser=_a_ellipsoid_): # in .karney, .trf, ...
449 '''(INTERNAL) Get an ellipsoid from C{(B{a_..}, B{f})} or C{B{.._ellipsoid}},
450 an L{Ellipsoid} or L{Ellipsoid2} from L{Datum} or C{a_f2Tuple}.
451 '''
452 if f is None:
453 E, _ = _En2(a_ellipsoid, name)
454 if raiser and not E:
455 _xinstanceof(Ellipsoid, Ellipsoid2, a_f2Tuple, Datum, **{raiser: a_ellipsoid})
456 else:
457 E = Ellipsoid2(a_ellipsoid, f, name=name)
458 return E
461def _ellipsoidal_datum(earth, Error=TypeError, name=NN, raiser=NN):
462 '''(INTERNAL) Create a L{Datum} from an L{Ellipsoid} or L{Ellipsoid2},
463 C{a_f2Tuple}, 2-tuple or 2-list B{C{earth}} model.
465 @kwarg raiser: If not C{NN}, raise an B{C{Error}} if not ellipsoidal.
466 '''
467 if isinstance(earth, Datum):
468 d = earth
469 else:
470 E, n = _En2(earth, name)
471 if not E:
472 n = raiser or _earth_
473 _xinstanceof(Datum, Ellipsoid, Ellipsoid2, a_f2Tuple, **{n: earth})
474 d = Datum(E, transform=Transforms.Identity, name=n)
475 if raiser and not d.isEllipsoidal:
476 raise _IsnotError(_ellipsoidal_, Error=Error, **{raiser: earth})
477 return d
480def _mean_radius(radius, *lats):
481 '''(INTERNAL) Compute the mean radius of a L{Datum} from an L{Ellipsoid},
482 L{Ellipsoid2} or scalar earth C{radius} over several latitudes.
483 '''
484 if radius is R_M:
485 r = radius
486 elif isscalar(radius):
487 r = Radius_(radius, low=0, Error=TypeError)
488 else:
489 E = _ellipsoidal_datum(radius).ellipsoid
490 r = fmean(map(E.Rgeocentric, lats)) if lats else E.Rmean
491 return r
494def _spherical_datum(earth, Error=TypeError, name=NN, raiser=NN):
495 '''(INTERNAL) Create a L{Datum} from an L{Ellipsoid}, L{Ellipsoid2},
496 C{a_f2Tuple}, 2-tuple, 2-list B{C{earth}} model or C{scalar} radius.
498 @kwarg raiser: If not C{NN}, raise an B{C{Error}} if not spherical.
499 '''
500 if isscalar(earth):
501 E = Datums.Sphere.ellipsoid
502 if earth == E.a == E.b and not name:
503 d = Datums.Sphere
504 else:
505 r = Radius_(earth, Error=Error) # invalid datum
506 n = _UNDER(name)
507 E = Ellipsoid(r, r, name=n)
508 d = Datum(E, transform=Transforms.Identity, name=n)
509 else:
510 d = _ellipsoidal_datum(earth, Error=Error, name=name)
511 if raiser and not d.isSpherical:
512 raise _IsnotError(_spherical_, Error=Error, **{raiser: earth})
513 return d
516class Datums(_NamedEnum):
517 '''(INTERNAL) L{Datum} registry, I{must} be a sub-class
518 to accommodate the L{_LazyNamedEnumItem} properties.
519 '''
520 def _Lazy(self, ellipsoid_name, transform_name, name=NN):
521 '''(INTERNAL) Instantiate the L{Datum}.
522 '''
523 return Datum(Ellipsoids.get(ellipsoid_name),
524 Transforms.get(transform_name), name=name)
526Datums = Datums(Datum) # PYCHOK singleton
527'''Some pre-defined L{Datum}s, all I{lazily} instantiated.'''
528# Datums with associated ellipsoid and Helmert transform parameters
529# to convert from WGS84 into the given datum. More are available at
530# <https://Earth-Info.NGA.mil/GandG/coordsys/datums/NATO_DT.pdf> and
531# <XXX://www.FieldenMaps.info/cconv/web/cconv_params.js>.
532Datums._assert(
533 # Belgian Datum 1972, based on Hayford ellipsoid.
534 # <https://NL.WikiPedia.org/wiki/Belgian_Datum_1972>
535 # <https://SpatialReference.org/ref/sr-org/7718/html/>
536 BD72 = _lazy(_BD72_, _Intl1924_, _BD72_),
538 # Germany <https://WikiPedia.org/wiki/Bessel-Ellipsoid>
539 # <https://WikiPedia.org/wiki/Helmert_transformation>
540 DHDN = _lazy(_DHDN_, _Bessel1841_, _DHDN_),
542 # <https://www.Gov.UK/guidance/oil-and-gas-petroleum-operations-notices#pon-4>
543 ED50 = _lazy(_ED50_, _Intl1924_, _ED50_),
545 # Australia <https://ICSM.Gov.AU/datum/gda2020-and-gda94-technical-manuals>
546# ADG66 = _lazy(_ADG66_, _ANS_, _WGS84_), # XXX Transform?
547# ADG84 = _lazy(_ADG84_, _ANS_, _WGS84_), # XXX Transform?
548# GDA94 = _lazy(_GDA94_, _GRS80_, _WGS84_),
549 GDA2020 = _lazy(_GDA2020_, _GRS80_, _WGS84_), # XXX Transform?
551 # <https://WikiPedia.org/wiki/GRS_80>
552 GRS80 = _lazy(_GRS80_, _GRS80_, _WGS84_),
554 # <https://OSI.IE/wp-content/uploads/2015/05/transformations_booklet.pdf> Table 2
555# Irl1975 = _lazy(_Irl1965_, _AiryModified_, _Irl1965_),
556 Irl1975 = _lazy(_Irl1975_, _AiryModified_, _Irl1975_),
558 # Germany <https://WikiPedia.org/wiki/Helmert_transformation>
559 Krassovski1940 = _lazy(_Krassovski1940_, _Krassovski1940_, _Krassovski1940_), # XXX spelling?
560 Krassowsky1940 = _lazy(_Krassowsky1940_, _Krassowsky1940_, _Krassowsky1940_), # XXX spelling?
562 # Austria <https://DE.WikiPedia.org/wiki/Datum_Austria>
563 MGI = _lazy(_MGI_, _Bessel1841_, _MGI_),
565 # <https://WikiPedia.org/wiki/Helmert_transformation>
566 NAD27 = _lazy(_NAD27_, _Clarke1866_, _NAD27_),
568 # NAD83 (2009) == WGS84 - <https://www.UVM.edu/giv/resources/WGS84_NAD83.pdf>
569 # (If you *really* must convert WGS84<->NAD83, you need more than this!)
570 NAD83 = _lazy(_NAD83_, _GRS80_, _NAD83_),
572 # Nouvelle Triangulation Francaise (Paris) XXX verify
573 NTF = _lazy(_NTF_, _Clarke1880IGN_, _NTF_),
575 # <https://www.OrdnanceSurvey.co.UK/docs/support/guide-coordinate-systems-great-britain.pdf>
576 OSGB36 = _lazy(_OSGB36_, _Airy1830_, _OSGB36_),
578 # Germany <https://WikiPedia.org/wiki/Helmert_transformation>
579 Potsdam = _lazy(_Potsdam_, _Bessel1841_, _Bessel1841_),
581 # XXX psuedo-ellipsoids for spherical LatLon
582 Sphere = _lazy(_Sphere_, _Sphere_, _WGS84_),
584 # <https://www.GeoCachingToolbox.com?page=datumEllipsoidDetails>
585 TokyoJapan = _lazy(_TokyoJapan_, _Bessel1841_, _TokyoJapan_),
587 # <https://www.ICAO.int/safety/pbn/documentation/eurocontrol/eurocontrol%20wgs%2084%20implementation%20manual.pdf>
588 WGS72 = _lazy(_WGS72_, _WGS72_, _WGS72_),
590 WGS84 = _lazy(_WGS84_, _WGS84_, _WGS84_),
591)
593_WGS84 = Datums.WGS84 # PYCHOK exported internally
595if __name__ == '__main__':
597 from pygeodesy.interns import _COMMA_, _NL_, _NLATvar_
598 from pygeodesy.lazily import printf
600 # __doc__ of this file, force all into registery
601 for r in (Datums, Transforms):
602 t = [NN] + r.toRepr(all=True, asorted=True).split(_NL_)
603 printf(_NLATvar_.join(i.strip(_COMMA_) for i in t))
605# **) MIT License
606#
607# Copyright (C) 2016-2023 -- mrJean1 at Gmail -- All Rights Reserved.
608#
609# Permission is hereby granted, free of charge, to any person obtaining a
610# copy of this software and associated documentation files (the "Software"),
611# to deal in the Software without restriction, including without limitation
612# the rights to use, copy, modify, merge, publish, distribute, sublicense,
613# and/or sell copies of the Software, and to permit persons to whom the
614# Software is furnished to do so, subject to the following conditions:
615#
616# The above copyright notice and this permission notice shall be included
617# in all copies or substantial portions of the Software.
618#
619# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
620# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
621# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
622# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
623# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
624# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
625# OTHER DEALINGS IN THE SOFTWARE.