Coverage for pygeodesy/elevations.py: 80%
69 statements
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« prev ^ index » next coverage.py v7.6.1, created at 2025-01-06 12:20 -0500
2# -*- coding: utf-8 -*-
4u'''Web-services-based elevations and C{CONUS} geoid heights.
6Functions to obtain elevations and geoid heights thru web services,
7for (lat, lon) locations, currently limited to the U{Conterminous
8US (CONUS)<https://WikiPedia.org/wiki/Contiguous_United_States>},
9see also modules L{pygeodesy.geoids} and L{pygeodesy.heights} and
10U{USGS10mElev.py<https://Gist.GitHub.com/pyRobShrk>}.
12@see: Module L{pygeodesy.geoids} to get geoid heights from other
13 sources and for regions other than C{CONUS}.
15@note: If on B{macOS} an C{SSLCertVerificationError} occurs, like
16 I{"[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed:
17 self "signed certificate in certificate chain ..."}, review
18 U{this post<https://StackOverflow.com/questions/27835619/
19 urllib-and-ssl-certificate-verify-failed-error>} for a remedy.
20 From a C{Terminal} window run:
21 C{"/Applications/Python\\ X.Y/Install\\ Certificates.command"}
22'''
24from pygeodesy.basics import clips, ub2str
25from pygeodesy.errors import ParseError, _xkwds_get
26from pygeodesy.interns import NN, _AMPERSAND_, _COLONSPACE_, \
27 _elevation_, _height_, _LCURLY_, \
28 _n_a_, _no_, _RCURLY_, _SPACE_
29from pygeodesy.lazily import _ALL_LAZY
30from pygeodesy.named import _NamedTuple
31from pygeodesy.streprs import fabs, Fmt, fstr, lrstrip
32from pygeodesy.units import Lat, Lon, Meter, Scalar, Str
34# from math import fabs # from .karney
36__all__ = _ALL_LAZY.elevations
37__version__ = '24.06.11'
39try:
40 from urllib2 import urlopen # quote, urlcleanup
41 from httplib import HTTPException as HTTPError
43except (ImportError, NameError): # Python 3+
44 from urllib.request import urlopen # urlcleanup
45 # from urllib.parse import quote
46 from urllib.error import HTTPError
48_JSON_ = 'JSON'
49_QUESTION_ = '?'
50_XML_ = 'XML'
52try:
53 from json import loads as _json
54except ImportError:
56 from pygeodesy.interns import _COMMA_, _QUOTE2_
57 _QUOTE2COLONSPACE_ = _QUOTE2_ + _COLONSPACE_
59 def _json(ngs):
60 '''(INTERNAL) Convert an NGS response in JSON to a C{dict}.
61 '''
62 # b'{"geoidModel": "GEOID12A",
63 # "station": "UserStation",
64 # "lat": 37.8816,
65 # "latDms": "N375253.76000",
66 # "lon": -121.9142,
67 # "lonDms": "W1215451.12000",
68 # "geoidHeight": -31.703,
69 # "error": 0.064
70 # }'
71 #
72 # or in case of errors:
73 #
74 # b'{"error": "No suitable Geoid model found for model 15"
75 # }'
76 d = {}
77 for t in lrstrip(ngs.strip(), lrpairs={_LCURLY_: _RCURLY_}).split(_COMMA_):
78 t = t.strip()
79 j = t.strip(_QUOTE2_).split(_QUOTE2COLONSPACE_)
80 if len(j) != 2:
81 raise ParseError(json=t)
82 k, v = j
83 try:
84 v = float(v)
85 except (TypeError, ValueError):
86 v = Str(ub2str(v.lstrip().lstrip(_QUOTE2_)), name=k)
87 d[k] = v
88 return d
91def _error(fun, lat, lon, e):
92 '''(INTERNAL) Format an error
93 '''
94 return _COLONSPACE_(Fmt.PAREN(fun.__name__, fstr((lat, lon))), e)
97def _qURL(url, timeout=2, **params):
98 '''(INTERNAL) Build B{C{url}} query, get and verify response.
99 '''
100 if params: # build url query, don't map(quote, params)!
101 p = _AMPERSAND_(*(Fmt.EQUAL(p, v) for p, v in params.items() if v))
102 if p:
103 url = NN(url, _QUESTION_, p)
104 u = urlopen(url, timeout=timeout) # secs
106 s = u.getcode()
107 if s != 200: # http.HTTPStatus.OK or http.client.OK
108 raise HTTPError('code %d: %s' % (s, u.geturl()))
110 r = u.read()
111 u.close()
112 # urlcleanup()
113 return ub2str(r).strip()
116def _xml(tag, xml):
117 '''(INTERNAL) Get a <tag>value</tag> from XML.
118 '''
119 # b'<?xml version="1.0" encoding="utf-8" ?>
120 # <USGS_Elevation_Point_Query_Service>
121 # <Elevation_Query x="-121.914200" y="37.881600">
122 # <Data_Source>3DEP 1/3 arc-second</Data_Source>
123 # <Elevation>3851.03</Elevation>
124 # <Units>Feet</Units>
125 # </Elevation_Query>
126 # </USGS_Elevation_Point_Query_Service>'
127 i = xml.find(Fmt.TAG(tag))
128 if i > 0:
129 i += len(tag) + 2
130 j = xml.find(Fmt.TAGEND(tag), i)
131 if j > i:
132 return Str(xml[i:j].strip(), name=tag)
133 return _no_(_XML_, Fmt.TAG(tag)) # PYCHOK no cover
136class Elevation2Tuple(_NamedTuple): # .elevations.py
137 '''2-Tuple C{(elevation, data_source)} in C{meter} and C{str}.
138 '''
139 _Names_ = (_elevation_, 'data_source')
140 _Units_ = ( Meter, Str)
143def elevation2(lat, lon, timeout=2.0):
144 '''Get the geoid elevation at an C{NAD83} to C{NAVD88} location.
146 @arg lat: Latitude (C{degrees}).
147 @arg lon: Longitude (C{degrees}).
148 @kwarg timeout: Optional, query timeout (seconds).
150 @return: An L{Elevation2Tuple}C{(elevation, data_source)}
151 or (C{None, "error"}) in case of errors.
153 @raise ValueError: Invalid B{C{timeout}}.
155 @note: The returned C{elevation is None} if B{C{lat}} or B{C{lon}} is
156 invalid or outside the C{Conterminous US (CONUS)}, if conversion
157 failed or if the query timed out. The C{"error"} is the C{HTTP-,
158 IO-, SSL-} or other C{-Error} as a string (C{str}).
160 @see: U{USGS Elevation Point Query Service<https://apps.NationalMap.gov/epqs/>}, the
161 U{FAQ<https://www.USGS.gov/faqs/what-are-projection-horizontal-and-vertical-
162 datum-units-and-resolution-3dep-standard-dems>}, U{geoid.py<https://Gist.GitHub.com/
163 pyRobShrk>}, module L{geoids}, classes L{GeoidG2012B}, L{GeoidKarney} and
164 L{GeoidPGM}.
165 '''
166 try: # alt 'https://NED.USGS.gov/epqs/pqs.php', 'https://epqs.NationalMap.gov/v1'
167 x = _qURL('https://NationalMap.USGS.gov/epqs/pqs.php',
168 x=Lon(lon).toStr(prec=6),
169 y=Lat(lat).toStr(prec=6),
170 units='Meters', # 'Feet', capitalized
171 output=_XML_.lower(), # _JSON_, lowercase only
172 timeout=Scalar(timeout=timeout))
173 if x[:6] == '<?xml ':
174 e = _xml('Elevation', x)
175 try:
176 e = float(e)
177 if fabs(e) < 1e6:
178 return Elevation2Tuple(e, _xml('Data_Source', x))
179 e = 'non-CONUS %.2F' % (e,)
180 except (TypeError, ValueError):
181 pass
182 else: # PYCHOK no cover
183 e = _no_(_XML_, Fmt.QUOTE2(clips(x, limit=128, white=_SPACE_)))
184 except Exception as x: # (HTTPError, IOError, TypeError, ValueError)
185 e = repr(x)
186 e = _error(elevation2, lat, lon, e)
187 return Elevation2Tuple(None, e)
190class GeoidHeight2Tuple(_NamedTuple): # .elevations.py
191 '''2-Tuple C{(height, model_name)}, geoid C{height} in C{meter}
192 and C{model_name} as C{str}.
193 '''
194 _Names_ = (_height_, 'model_name')
195 _Units_ = ( Meter, Str)
198def geoidHeight2(lat, lon, model=0, timeout=2.0):
199 '''Get the C{NAVD88} geoid height at an C{NAD83} location.
201 @arg lat: Latitude (C{degrees}).
202 @arg lon: Longitude (C{degrees}).
203 @kwarg model: Optional, geoid model ID (C{int}).
204 @kwarg timeout: Optional, query timeout (seconds).
206 @return: An L{GeoidHeight2Tuple}C{(height, model_name)}
207 or C{(None, "error"}) in case of errors.
209 @raise ValueError: Invalid B{C{timeout}}.
211 @note: The returned C{height is None} if B{C{lat}} or B{C{lon}} is
212 invalid or outside the C{Conterminous US (CONUS)}, if the
213 B{C{model}} was invalid, if conversion failed or if the query
214 timed out. The C{"error"} is the C{HTTP-, IO-, SSL-, URL-}
215 or other C{-Error} as a string (C{str}).
217 @see: U{NOAA National Geodetic Survey
218 <https://www.NGS.NOAA.gov/INFO/geodesy.shtml>},
219 U{Geoid<https://www.NGS.NOAA.gov/web_services/geoid.shtml>},
220 U{USGS10mElev.py<https://Gist.GitHub.com/pyRobShrk>}, module
221 L{geoids}, classes L{GeoidG2012B}, L{GeoidKarney} and
222 L{GeoidPGM}.
223 '''
224 try:
225 j = _qURL('https://Geodesy.NOAA.gov/api/geoid/ght',
226 lat=Lat(lat).toStr(prec=6),
227 lon=Lon(lon).toStr(prec=6),
228 model=(model if model else NN),
229 timeout=Scalar(timeout=timeout)) # PYCHOK indent
230 if j[:1] == _LCURLY_ and j[-1:] == _RCURLY_ and j.find('"error":') > 0:
231 d, e = _json(j), 'geoidHeight'
232 if isinstance(_xkwds_get(d, error=_n_a_), float):
233 h = d.get(e, None)
234 if h is not None:
235 m = _xkwds_get(d, geoidModel=_n_a_)
236 return GeoidHeight2Tuple(h, m)
237 else:
238 e = _JSON_
239 e = _no_(e, Fmt.QUOTE2(clips(j, limit=256, white=_SPACE_)))
240 except Exception as x: # (HTTPError, IOError, ParseError, TypeError, ValueError)
241 e = repr(x)
242 e = _error(geoidHeight2, lat, lon, e)
243 return GeoidHeight2Tuple(None, e)
246if __name__ == '__main__':
248 from pygeodesy import printf
249 # <https://WikiPedia.org/wiki/Mount_Diablo>
250 for f in (elevation2, # (1173.79, '3DEP 1/3 arc-second')
251 geoidHeight2): # (-31.699, u'GEOID12B')
252 t = f(37.8816, -121.9142)
253 printf(_COLONSPACE_(f.__name__, t))
255# **) MIT License
256#
257# Copyright (C) 2016-2025 -- mrJean1 at Gmail -- All Rights Reserved.
258#
259# Permission is hereby granted, free of charge, to any person obtaining a
260# copy of this software and associated documentation files (the "Software"),
261# to deal in the Software without restriction, including without limitation
262# the rights to use, copy, modify, merge, publish, distribute, sublicense,
263# and/or sell copies of the Software, and to permit persons to whom the
264# Software is furnished to do so, subject to the following conditions:
265#
266# The above copyright notice and this permission notice shall be included
267# in all copies or substantial portions of the Software.
268#
269# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
270# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
271# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
272# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
273# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
274# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
275# OTHER DEALINGS IN THE SOFTWARE.
277# % python -m pygeodesy.elevations
278# elevation2: (1173.79, '3DEP 1/3 arc-second')
279# geoidHeight2: (-31.703, 'GEOID12B')