Coverage for /wheeldirectory/casa-6.7.0-12-py3.10.el8/lib/py/lib/python3.10/site-packages/casatasks/private/task_getantposalma.py: 85%
92 statements
« prev ^ index » next coverage.py v7.6.4, created at 2024-10-31 19:53 +0000
1from casatasks import casalog
2from casatools import quanta
3import certifi
4from datetime import datetime
5import json, os, shutil
6import ssl
7from urllib import request
8from urllib.error import HTTPError, URLError
9from urllib.parse import urlencode, urlparse
12def _is_valid_url_host(url):
13 parsed = urlparse(url)
14 return bool(parsed.netloc)
17def _query(url):
18 myjson = None
19 response = None
20 try:
21 context = ssl.create_default_context(cafile=certifi.where())
22 with request.urlopen(url, context=context, timeout=400) as response:
23 if response.status == 200:
24 myjson = response.read().decode('utf-8')
25 except HTTPError as e:
26 casalog.post(
27 f"Caught HTTPError: {e.code} {e.reason}: {e.read().decode('utf-8')}",
28 "WARN"
29 )
30 except URLError as e:
31 casalog.post(f"Caught URLError: {str(e)}", "WARN")
32 except Exception as e:
33 casalog.post(f"Caught Exception when trying to connect: {str(e)}", "WARN")
34 return myjson
37def getantposalma(
38 outfile='', overwrite=False, asdm='', tw='', snr=0, search='both_latest',
39 hosts=['tbd1.alma.cl', 'tbd2.alma.cl']
40):
41 r"""
42Retrieve antenna positions by querying ALMA web service.
44[`Description`_] [`Examples`_] [`Development`_] [`Details`_]
47Parameters
48 - outfile_ (path='') - Name of output file to which to write retrieved antenna positions.
49 - overwrite_ (bool=False) - Overwrite a file by the same name if it exists?
50 - asdm_ (string='') - The associated ASDM name. Must be specified
51 - tw_ (string='') - Optional time window in which to consider baseline measurements in the database, when calculating the antenna positions.
52 - snr_ (float=0) - Optional signal-to-noise.
53 - search_ (string='both_latest') - Search algorithm to use.
54 - hosts_ (stringVec=['https://asa.alma.cl/uncertainties-service/uncertainties/versions/last/measurements/casa/']) - Priority-ranked list of hosts to query.
59.. _Description:
61Description
63.. warning:: **WARNING**: This task should be considered experimental
64 since the values returned by the JAO service are in the process of
65 being validated.
67This task retrieves ALMA antenna positions via a web service which runs
68on an ALMA-hosted server. The antenna positions are with respect to ITRF.
69The user must specify the value of the outfile parameter. This parameter
70is the name of the file to which the antenna positions will be written.
71This file can then be read by gencal so that it can use the most up to
72date antenna positions for the observation.
74The web service is described by the server development team and can be
75found `at this location <https://asw.alma.cl/groups/ASW/-/packages/843>`__.
77The input parameters are discussed in detail below.
79outfile is required to be specified. It is the name of the file to which to
80write antenna positions.
82overwrite If False and a file with the same name exists, and exception
83will be thrown. If true, an existing file with the same name will be
84overwriten.
86asdm is required to be specified. It is the associated ASDM UID in the
87form uid://A002/Xc02418/X29c8.
89tw is an optional parameter. It is time window in which the antenna positions
90are required, specified as a comma separated pair. Times are UTC and are
91expressed in YY-MM-DDThh:mm:ss.sss format. The end time must be later than
92the begin time.
94snr is an optional parameter. It is the signal-to-noise ratio. Antenna
95positions which have corrections less than this value will not be written.
96If not specified, positions of all antennas will be written.
98tw and search are optional parameters and are coupled as follows. search
99indicates the search algorithm to use to find the desired antenna positions.
100Supported values of this parameter at the time of writing are 'both_latest'
101and 'both_closest'. The task passes the value of the search parameter verbatim to
102the web service, meaning that users can take advantage of new search algorithms
103as the web service team brings them online. The default algorithm used is
104'both_latest'. In general, the search is limited in time to the specified
105value of tw (time window). However, in the case that tw is not specified, the
106following rules apply. For 'both_latest', the last updated position for each
107antenna within the specified time window, or, if tw is not specified, within
10830 days after the observation will be returned, taking into account snr if
109specified, if provided.
111For 'both_closest', if tw is not specified, the position
112of each antenna closest in time to the observation, within 30 days (before
113or after the observation) will be returned, subject to the value of snr if it
114is specified.
116hosts is a required parameter. It is a list of hosts to query, in order of
117priority, to obtain positions. The first server to respond with a valid result is
118the only one that is used. That response will be written and no additional
119hosts will be queried.
121The format of the returned file is a two element list encoded in json. The first
122element is a stringfied dictionary that contains antenna names as keys, with each
123value being a three element list of x, y, and z coordinates in ITRF. The second
124element is a dictionary containing various (possibly helpful) metadata that were
125used when the task was run. The following code may be used to load these data
126structures into python variables.
128 ::
130 import ast, json
131 ...
132 with open("outfile.json", "r") as f:
133 antpos_str, md_dict = json.load(f)
134 antpos_dict = ast.literal_eval(antpos_str)
137.. _Examples:
139Examples
140 Get antenna positions which have positions with a signal-to-noise ratio
141 greater than 5.
143 ::
145 getantposalma(
146 outfile='my_ant_pos.json', asdm='valid ASDM name here', snr=5,
147 hosts=['tbd1.alma.cl', 'tbd2.alma.cl']
148 )
151.. _Development:
153Development
154 No additional development details
159.. _Details:
162Parameter Details
163 Detailed descriptions of each function parameter
165.. _outfile:
167| ``outfile (path='')`` - Name of output file to which to write antenna positions. If a file by this name already exists, it will be silently overwritten. The written file will be in JSON format.
168| default: none
169| Example: outfile='my_alma_antenna_positions.json'
171.. _overwrite:
173| ``overwrite (bool=False)`` - Overwrite a file by the same name if it exists? If False and a file
174| with the same name exists, and exception will be thrown.
176.. _asdm:
178| ``asdm (string='')`` - The associated ASDM name. Must be specified. The ASDM is not required to be on the file system; its value is simply passed to the web service.
179| default: ''
180| Example:asdm='uid://A002/X10ac6bc/X896d'
182.. _tw:
184| ``tw (string='')`` - Optional time window in which to consider baseline measurements in the database, when calculating the antenna positions. Format is of the form begin_time,end_time, where times must be specified in YYYY-MM-DDThh:mm:ss.sss format and end_time must be later than begin time. Times should be UTC.
185| Example: tw='2023-03-14T00:40:20,2023-03-20T17:58:20'
187.. _snr:
189| ``snr (float=0)`` - Optional signal-to-noise. Antenna positions which have corrections with S/N less than this value will not be retrieved nor written. If not specified, positions of all antennas will be written.
190| default: 0 (no snr constraint will be used)
191| Example: snr=5.0
193.. _search:
195| ``search (string='both_latest')`` - Search algorithm to use. Supported values are "both_latest" and "both_closest". For "both_latest", the last updated position for each antenna within 30 days after the observation will be returned, taking into account snr if specified. If provided, tw will override the 30 day default value. For "both_closest", the position of each antenna closest in time to the observation, within 30 days (before or after the observation) will be returned, subject to the value of snr if it is specified. If specified, the value of tw will override the default 30 days. The default algorithm to use will be "both_latest".
196| Example: search="both_closest"
198.. _hosts:
200| ``hosts (stringVec=['https://asa.alma.cl/uncertainties-service/uncertainties/versions/last/measurements/casa/'])`` - Priority-ranked list of hosts to query to obtain positions. Only one server that returns a list of antenna positions is required. That response will be written and no additional hosts will be queried.
201| Example: hosts=["server1.alma.cl", "server2.alma.cl"]
204 """
205 if not outfile:
206 raise ValueError("Parameter outfile must be specified")
207 md = {
208 "caltype": "ALMA antenna positions",
209 "description": "ALMA ITRF antenna positions in meters",
210 "product_code": "antposalma",
211 "outfile": outfile
212 }
213 if not overwrite and os.path.exists(outfile):
214 raise RuntimeError(
215 f"A file or directory named {outfile} already exists and overwrite "
216 "is False, so exiting. Either rename the existing file or directory, "
217 "change the value of overwrite to True, or both."
218 )
219 if not hosts:
220 raise ValueError("Parameter hosts must be specified")
221 if isinstance(hosts, list) and not hosts[0]:
222 raise ValueError("The first element of the hosts list must be specified")
223 md["hosts"] = hosts
224 _qa = quanta()
225 parms = {}
226 if asdm:
227 parms['asdm'] = asdm
228 else:
229 raise ValueError("parameter asdm must be specified")
230 if tw:
231 z = tw.split(",")
232 if len(z) != 2:
233 raise ValueError(
234 "Parameter tw should contain exactly one comma that separates two times"
235 )
236 s0, s1 = z
237 msg = "The correct format is of the form YYYY-MM-DDThh:mm:ss."
238 try:
239 t_start = _qa.quantity(_qa.time(s0, form="fits")[0])
240 except Exception as e:
241 raise ValueError(f"Begin time {s0} does not appear to have a valid format. {msg}")
242 try:
243 t_end = _qa.quantity(_qa.time(s1, form="fits")[0])
244 except Exception as e:
245 raise ValueError(f"End time {s1} does not appear to have a valid format. {msg}")
246 if _qa.ge(t_start, t_end):
247 raise ValueError(
248 f"Parameter tw, start time ({z[0]}) must be less than end time ({z[1]})."
249 )
250 parms["tw"] = tw
251 if snr < 0:
252 raise ValueError(f"Parameter snr ({snr}) must be non-negative.")
253 elif snr > 0:
254 parms["snr"] = snr
255 if search:
256 parms['search'] = search
257 qs = f"?{urlencode(parms)}"
258 md.update(parms)
259 antpos = None
260 for h in hosts:
261 if not _is_valid_url_host(h):
262 raise ValueError(
263 f'Parameter hosts: {h} is not a valid host expressed as a URL.'
264 )
265 url = f"{h}/{qs}"
266 casalog.post(f"Trying {url} ...", "NORMAL")
267 antpos = _query(url)
268 if antpos:
269 md["successful_url"] = url
270 antpos = json.loads(antpos)
271 break
272 if not antpos:
273 raise RuntimeError("All URLs failed to return an antenna position list.")
274 if os.path.exists(outfile):
275 if overwrite:
276 if os.path.isdir(outfile):
277 casalog.post(
278 f"Removing existing directory {outfile} before writing new "
279 "file of same name",
280 "WARN"
281 )
282 shutil.rmtree(outfile)
283 else:
284 casalog.post(
285 f"Removing existing file {outfile} before writing now file of "
286 "same name",
287 "WARN"
288 )
289 os.remove(outfile)
290 else:
291 raise RuntimeError(
292 "Logic Error: shouldn't have gotten to this point with overwrite=False"
293 )
294 md["timestamp"] = str(datetime.now())
295 with open(outfile, "w") as f:
296 json.dump({"data": antpos, "metadata": md}, f)