# http://pyrocko.org - GPLv3
#
# The Pyrocko Developers, 21st Century
# ---|P------/S----------~Lg----------
'''
GNSS station and campaign data model.
'''
import logging
import math
import numpy as num
from collections import OrderedDict
import pyrocko.orthodrome as od
from pyrocko.guts import (Object, Float, String, List, StringChoice,
DateTimestamp)
from pyrocko.model import Location
guts_prefix = 'pf.gnss'
logger = logging.getLogger('pyrocko.model.gnss')
[docs]class GNSSComponent(Object):
'''
Component of a GNSSStation
'''
unit = StringChoice.T(
choices=['mm', 'cm', 'm'],
help='Unit of displacement',
default='m')
shift = Float.T(
default=0.,
help="Component's shift in unit")
sigma = Float.T(
default=0.,
help='One sigma uncertainty of the measurement')
def __add__(self, other):
if not isinstance(other, self.__class__):
raise AttributeError('Other has to be of instance %s'
% self.__class__)
comp = self.__class__()
comp.shift = self.shift + other.shift
comp.sigma = math.sqrt(self.sigma**2 + other.sigma**2)
return comp
def __iadd__(self, other):
self.shift += other.shift
self.sigma = math.sqrt(self.sigma**2 + other.sigma**2)
return self
[docs]class GNSSStation(Location):
'''
Representation of a GNSS station during a campaign measurement
For more information see
http://kb.unavco.org/kb/assets/660/UNAVCO_Campaign_GPS_GNSS_Handbook.pdf
'''
code = String.T(
help='Four letter station code',
optional=True)
style = StringChoice.T(
choices=['static', 'rapid_static', 'kinematic'],
default='static')
survey_start = DateTimestamp.T(
optional=True,
help='Survey start time')
survey_end = DateTimestamp.T(
optional=True,
help='Survey end time')
correlation_ne = Float.T(
default=0.,
help='North-East component correlation')
correlation_eu = Float.T(
default=0.,
help='East-Up component correlation')
correlation_nu = Float.T(
default=0.,
help='North-Up component correlation')
north = GNSSComponent.T(
optional=True)
east = GNSSComponent.T(
optional=True)
up = GNSSComponent.T(
optional=True)
def __eq__(self, other):
try:
return self.code == other.code
except AttributeError:
return False
def get_covariance_matrix(self):
components = self.components.values()
ncomponents = self.ncomponents
covar = num.zeros((ncomponents, ncomponents))
for ic1, comp1 in enumerate(components):
for ic2, comp2 in enumerate(components):
corr = self._get_comp_correlation(comp1, comp2)
covar[ic1, ic2] = corr * comp1.sigma * comp2.sigma
# This floating point operation is inaccurate:
# corr * comp1.sigma * comp2.sigma != corr * comp2.sigma * comp1.sigma
#
# Hence this identity
covar[num.tril_indices_from(covar, k=-1)] = \
covar[num.triu_indices_from(covar, k=1)]
return covar
def get_correlation_matrix(self):
components = self.components.values()
ncomponents = self.ncomponents
corr = num.zeros((ncomponents, ncomponents))
corr[num.diag_indices_from(corr)] = num.array(
[c.sigma for c in components])
for ic1, comp1 in enumerate(components):
for ic2, comp2 in enumerate(components):
if comp1 is comp2:
continue
corr[ic1, ic2] = self._get_comp_correlation(comp1, comp2)
# See comment at get_covariance_matrix
corr[num.tril_indices_from(corr, k=-1)] = \
corr[num.triu_indices_from(corr, k=1)]
return corr
def get_displacement_data(self):
return num.array([c.shift for c in self.components.values()])
def get_component_mask(self):
return num.array(
[False if self.__getattribute__(name) is None else True
for name in ('north', 'east', 'up')], dtype=bool)
@property
def components(self):
return OrderedDict(
[(name, self.__getattribute__(name))
for name in ('north', 'east', 'up')
if self.__getattribute__(name) is not None])
@property
def ncomponents(self):
return len(self.components)
def _get_comp_correlation(self, comp1, comp2):
if comp1 is comp2:
return 1.
s = self
correlation_map = {
(s.north, s.east): s.correlation_ne,
(s.east, s.up): s.correlation_eu,
(s.north, s.up): s.correlation_nu
}
return correlation_map.get(
(comp1, comp2),
correlation_map.get((comp2, comp1), False))
[docs]class GNSSCampaign(Object):
stations = List.T(
GNSSStation.T(),
help='List of GNSS campaign measurements')
name = String.T(
help='Campaign name',
default='Unnamed campaign')
survey_start = DateTimestamp.T(
optional=True)
survey_end = DateTimestamp.T(
optional=True)
def __init__(self, *args, **kwargs):
Object.__init__(self, *args, **kwargs)
self._cov_mat = None
self._cor_mat = None
def add_station(self, station):
self._cor_mat = None
self._cov_mat = None
return self.stations.append(station)
def remove_station(self, station_code):
try:
station = self.get_station(station_code)
self.stations.remove(station)
self._cor_mat = None
self._cov_mat = None
except ValueError:
logger.warning('Station {} does not exist in campaign, '
'do nothing.'.format(station_code))
def get_station(self, station_code):
for sta in self.stations:
if sta.code == station_code:
return sta
raise ValueError('Could not find station %s' % station_code)
def get_center_latlon(self):
return od.geographic_midpoint_locations(self.stations)
def get_radius(self):
coords = self.coordinates
return od.distance_accurate50m(
coords[:, 0].min(), coords[:, 1].min(),
coords[:, 0].max(), coords[:, 1].max()) / 2.
def get_covariance_matrix(self):
if self._cov_mat is None:
ncomponents = self.ncomponents
cov_arr = num.zeros((ncomponents, ncomponents))
idx = 0
for ista, sta in enumerate(self.stations):
ncomp = sta.ncomponents
cov_arr[idx:idx+ncomp, idx:idx+ncomp] = \
sta.get_covariance_matrix()
idx += ncomp
self._cov_mat = cov_arr
return self._cov_mat
def get_correlation_matrix(self):
if self._cor_mat is None:
ncomponents = self.ncomponents
cor_arr = num.zeros((ncomponents, ncomponents))
idx = 0
for ista, sta in enumerate(self.stations):
ncomp = sta.ncomponents
cor_arr[idx:idx+ncomp, idx:idx+ncomp] = \
sta.get_correlation_matrix()
idx += ncomp
self._cor_mat = cor_arr
return self._cor_mat
def get_component_mask(self):
return num.concatenate(
[s.get_component_mask() for s in self.stations])
def dump(self, *args, **kwargs):
self.regularize()
return Object.dump(self, *args, **kwargs)
@property
def coordinates(self):
return num.array([loc.effective_latlon for loc in self.stations])
@property
def nstations(self):
return len(self.stations)
@property
def ncomponents(self):
return sum([s.ncomponents for s in self.stations])
