Source code for obspy.io.ah.core

# -*- coding: utf-8 -*-
"""
AH bindings to ObsPy core module.

An AH file is used for the storage of binary seismic time series data.
The file is portable among machines of varying architecture by virtue of
its XDR implementation. It is composed of a variable-sized header containing
a number of values followed by the time series data.

.. seealso:: ftp://www.orfeus-eu.org/pub/software/mirror/ldeo.columbia/

:copyright:
    The ObsPy Development Team (devs@obspy.org)
:license:
    GNU Lesser General Public License, Version 3
    (https://www.gnu.org/copyleft/lesser.html)
"""
from __future__ import (absolute_import, division, print_function,
                        unicode_literals)
from future.builtins import *  # NOQA @UnusedWildImport

import sys
import xdrlib

import numpy as np

from obspy import Stream, Trace, UTCDateTime
from obspy.core.util.attribdict import AttribDict
from obspy.core.util.deprecation_helpers import \
    DynamicAttributeImportRerouteModule


[docs]def _is_ah(filename): """ Checks whether a file is AH waveform data or not. :type filename: str :param filename: AH file to be checked. :rtype: bool :return: ``True`` if a AH waveform file. """ if _get_ah_version(filename): return True return False
[docs]def _read_ah(filename, **kwargs): # @UnusedVariable """ Reads an AH waveform file and returns a Stream object. .. warning:: This function should NOT be called directly, it registers via the ObsPy :func:`~obspy.core.stream.read` function, call this instead. :type filename: str :param filename: AH file to be read. :rtype: :class:`~obspy.core.stream.Stream` :returns: Stream with Traces specified by given file. """ version = _get_ah_version(filename) if version == '2.0': return _read_ah2(filename) else: return _read_ah1(filename)
[docs]def _get_ah_version(filename): """ Returns version of AH waveform data. :type filename: str :param filename: AH v1 file to be checked. :rtype: str or False :return: version string of AH waveform data or ``False`` if unknown. """ with open(filename, "rb") as fh: # read first 8 bytes with XDR library try: data = xdrlib.Unpacker(fh.read(8)) # check for magic version number magic = data.unpack_int() except: return False if magic == 1100: try: # get record length length = data.unpack_uint() # read first record fh.read(length) except: return False # seems to be AH v2 return '2.0' elif magic == 6: # AH1 has no magic variable :/ # so we have to use some fixed values as indicators try: fh.seek(12) if xdrlib.Unpacker(fh.read(4)).unpack_int() != 6: return False fh.seek(24) if xdrlib.Unpacker(fh.read(4)).unpack_int() != 8: return False fh.seek(700) if xdrlib.Unpacker(fh.read(4)).unpack_int() != 80: return False fh.seek(784) if xdrlib.Unpacker(fh.read(4)).unpack_int() != 202: return False except: return False return '1.0' else: return False
[docs]def _unpack_string(data): return data.unpack_string().split(b'\x00', 1)[0].strip().decode("utf-8")
[docs]def _read_ah1(filename): """ Reads an AH v1 waveform file and returns a Stream object. :type filename: str :param filename: AH v1 file to be read. :rtype: :class:`~obspy.core.stream.Stream` :returns: Stream with Traces specified by given file. """ def _unpack_trace(data): ah_stats = AttribDict({ 'version': '1.0', 'event': AttribDict(), 'station': AttribDict(), 'record': AttribDict(), 'extras': [] }) # station info ah_stats.station.code = _unpack_string(data) ah_stats.station.channel = _unpack_string(data) ah_stats.station.type = _unpack_string(data) ah_stats.station.latitude = data.unpack_float() ah_stats.station.longitude = data.unpack_float() ah_stats.station.elevation = data.unpack_float() ah_stats.station.gain = data.unpack_float() ah_stats.station.normalization = data.unpack_float() # A0 poles = [] zeros = [] for _i in range(0, 30): r = data.unpack_float() i = data.unpack_float() poles.append(complex(r, i)) r = data.unpack_float() i = data.unpack_float() zeros.append(complex(r, i)) # first value describes number of poles/zeros npoles = int(poles[0].real) + 1 nzeros = int(zeros[0].real) + 1 ah_stats.station.poles = poles[1:npoles] ah_stats.station.zeros = zeros[1:nzeros] # event info ah_stats.event.latitude = data.unpack_float() ah_stats.event.longitude = data.unpack_float() ah_stats.event.depth = data.unpack_float() ot_year = data.unpack_int() ot_mon = data.unpack_int() ot_day = data.unpack_int() ot_hour = data.unpack_int() ot_min = data.unpack_int() ot_sec = data.unpack_float() try: ot = UTCDateTime(ot_year, ot_mon, ot_day, ot_hour, ot_min, ot_sec) except: ot = None ah_stats.event.origin_time = ot ah_stats.event.comment = _unpack_string(data) # record info ah_stats.record.type = dtype = data.unpack_int() # data type ah_stats.record.ndata = ndata = data.unpack_uint() # number of samples ah_stats.record.delta = data.unpack_float() # sampling interval ah_stats.record.max_amplitude = data.unpack_float() at_year = data.unpack_int() at_mon = data.unpack_int() at_day = data.unpack_int() at_hour = data.unpack_int() at_min = data.unpack_int() at_sec = data.unpack_float() at = UTCDateTime(at_year, at_mon, at_day, at_hour, at_min, at_sec) ah_stats.record.start_time = at ah_stats.record.abscissa_min = data.unpack_float() ah_stats.record.comment = _unpack_string(data) ah_stats.record.log = _unpack_string(data) # extras ah_stats.extras = data.unpack_array(data.unpack_float) # unpack data using dtype from record info if dtype == 1: # float temp = data.unpack_farray(ndata, data.unpack_float) elif dtype == 6: # double temp = data.unpack_farray(ndata, data.unpack_double) else: # e.g. 3 (vector), 2 (complex), 4 (tensor) msg = 'Unsupported AH v1 record type %d' raise NotImplementedError(msg % (dtype)) tr = Trace(np.array(temp)) tr.stats.ah = ah_stats tr.stats.delta = ah_stats.record.delta tr.stats.starttime = ah_stats.record.start_time tr.stats.station = ah_stats.station.code tr.stats.channel = ah_stats.station.channel return tr st = Stream() with open(filename, "rb") as fh: # read with XDR library data = xdrlib.Unpacker(fh.read()) # loop as long we can read records while True: try: tr = _unpack_trace(data) st.append(tr) except EOFError: break return st
[docs]def _read_ah2(filename): """ Reads an AH v2 waveform file and returns a Stream object. :type filename: str :param filename: AH v2 file to be read. :rtype: :class:`~obspy.core.stream.Stream` :returns: Stream with Traces specified by given file. """ def _unpack_trace(data): ah_stats = AttribDict({ 'version': '2.0', 'event': AttribDict(), 'station': AttribDict(), 'record': AttribDict(), 'extras': [] }) # station info data.unpack_int() # undocumented extra int? ah_stats.station.code = _unpack_string(data) data.unpack_int() # here too? ah_stats.station.channel = _unpack_string(data) data.unpack_int() # and again? ah_stats.station.type = _unpack_string(data) ah_stats.station.recorder = _unpack_string(data) ah_stats.station.sensor = _unpack_string(data) ah_stats.station.azimuth = data.unpack_float() # degrees E from N ah_stats.station.dip = data.unpack_float() # up = -90, down = +90 ah_stats.station.latitude = data.unpack_double() ah_stats.station.longitude = data.unpack_double() ah_stats.station.elevation = data.unpack_float() ah_stats.station.gain = data.unpack_float() ah_stats.station.normalization = data.unpack_float() # A0 npoles = data.unpack_int() ah_stats.station.poles = [] for _i in range(npoles): r = data.unpack_float() i = data.unpack_float() ah_stats.station.poles.append(complex(r, i)) nzeros = data.unpack_int() ah_stats.station.zeros = [] for _i in range(nzeros): r = data.unpack_float() i = data.unpack_float() ah_stats.station.zeros.append(complex(r, i)) ah_stats.station.comment = _unpack_string(data) # event info ah_stats.event.latitude = data.unpack_double() ah_stats.event.longitude = data.unpack_double() ah_stats.event.depth = data.unpack_float() ot_year = data.unpack_int() ot_mon = data.unpack_int() ot_day = data.unpack_int() ot_hour = data.unpack_int() ot_min = data.unpack_int() ot_sec = data.unpack_float() try: ot = UTCDateTime(ot_year, ot_mon, ot_day, ot_hour, ot_min, ot_sec) except: ot = None ah_stats.event.origin_time = ot data.unpack_int() # and again? ah_stats.event.comment = _unpack_string(data) # record info ah_stats.record.type = dtype = data.unpack_int() # data type ah_stats.record.ndata = ndata = data.unpack_uint() # number of samples ah_stats.record.delta = data.unpack_float() # sampling interval ah_stats.record.max_amplitude = data.unpack_float() at_year = data.unpack_int() at_mon = data.unpack_int() at_day = data.unpack_int() at_hour = data.unpack_int() at_min = data.unpack_int() at_sec = data.unpack_float() at = UTCDateTime(at_year, at_mon, at_day, at_hour, at_min, at_sec) ah_stats.record.start_time = at ah_stats.record.units = _unpack_string(data) ah_stats.record.inunits = _unpack_string(data) ah_stats.record.outunits = _unpack_string(data) data.unpack_int() # and again? ah_stats.record.comment = _unpack_string(data) data.unpack_int() # and again? ah_stats.record.log = _unpack_string(data) # user attributes nusrattr = data.unpack_int() ah_stats.usrattr = {} for _i in range(nusrattr): key = _unpack_string(data) value = _unpack_string(data) ah_stats.usrattr[key] = value # unpack data using dtype from record info if dtype == 1: # float temp = data.unpack_farray(ndata, data.unpack_float) elif dtype == 6: # double temp = data.unpack_farray(ndata, data.unpack_double) else: # e.g. 3 (vector), 2 (complex), 4 (tensor) msg = 'Unsupported AH v2 record type %d' raise NotImplementedError(msg % (dtype)) tr = Trace(np.array(temp)) tr.stats.ah = ah_stats tr.stats.delta = ah_stats.record.delta tr.stats.starttime = ah_stats.record.start_time tr.stats.station = ah_stats.station.code tr.stats.channel = ah_stats.station.channel return tr st = Stream() with open(filename, "rb") as fh: # loop as long we can read records while True: try: # read first 8 bytes with XDR library data = xdrlib.Unpacker(fh.read(8)) # check magic version number magic = data.unpack_int() except EOFError: break if magic != 1100: raise Exception('Not a AH v2 file') try: # get record length length = data.unpack_uint() # read rest of record into XDR unpacker data = xdrlib.Unpacker(fh.read(length)) tr = _unpack_trace(data) st.append(tr) except EOFError: break return st # Remove once 0.11 has been released.
sys.modules[__name__] = DynamicAttributeImportRerouteModule( name=__name__, doc=__doc__, locs=locals(), original_module=sys.modules[__name__], import_map={}, function_map={ 'is_AH': 'obspy.io.ah.core._is_ah', 'read_AH': 'obspy.io.ah.core._read_ah', 'read_AH1': 'obspy.io.ah.core._read_ah1', 'read_AH2': 'obspy.io.ah.core._read_ah2', '_get_AH_version': 'obspy.io.ah.core._get_ah_version'})