def trim_multiple_events( st, origin, catalog, travel_time_df, pga_factor, pct_window_reject, gmpe, site_parameters, rupture_parameters, ): """ Uses a catalog (list of ScalarEvents) to handle cases where a trace might contain signals from multiple events. The catalog should contain events down to a low enough magnitude in relation to the events of interest. Overall, the algorithm is as follows: 1) For each earthquake in the catalog, get the P-wave travel time and estimated PGA at this station. 2) Compute the PGA (of the as-recorded horizontal channels). 3) Select the P-wave arrival times across all events for this record that are (a) within the signal window, and (b) the predicted PGA is greater than pga_factor times the PGA from step #1. 4) If any P-wave arrival times match the above criteria, then if any of the arrival times fall within in the first pct_window_reject*100% of the signal window, then reject the record. Otherwise, trim the record such that the end time does not include any of the arrivals selected in step #3. Args: st (StationStream): Stream of data. origin (ScalarEvent): ScalarEvent object associated with the StationStream. catalog (list): List of ScalarEvent objects. travel_time_df (DataFrame): A pandas DataFrame that contains the travel time information (obtained from gmprocess.waveform_processing.phase.create_travel_time_dataframe). The columns in the DataFrame are the station ids and the indices are the earthquake ids. pga_factor (float): A decimal factor used to determine whether the predicted PGA from an event arrival is significant enough that it should be considered for removal. pct_window_reject (float): A decimal from 0.0 to 1.0 used to determine if an arrival should be trimmed from the record, or if the entire record should be rejected. If the arrival falls within the first pct_window_reject * 100% of the signal window, then the entire record will be rejected. Otherwise, the record will be trimmed appropriately. gmpe (str): Short name of the GMPE to use. Must be defined in the modules file. site_parameters (dict): Dictionary of site parameters to input to the GMPE. rupture_parameters: Dictionary of rupture parameters to input to the GMPE. Returns: StationStream: Processed stream. """ if not st.passed: return st # Check that we know the signal split for each trace in the stream for tr in st: if not tr.hasParameter("signal_split"): return st signal_window_starttime = st[0].getParameter("signal_split")["split_time"] arrivals = travel_time_df[st[0].stats.network + "." + st[0].stats.station] arrivals = arrivals.sort_values() # Filter by any arrival times that appear in the signal window arrivals = arrivals[(arrivals > signal_window_starttime) & (arrivals < st[0].stats.endtime)] # Make sure we remove the arrival that corresponds to the event of interest if origin.id in arrivals.index: arrivals.drop(index=origin.id, inplace=True) if arrivals.empty: return st # Calculate the recorded PGA for this record stasum = StationSummary.from_stream(st, ["ROTD(50.0)"], ["PGA"]) recorded_pga = stasum.get_pgm("PGA", "ROTD(50.0)") # Load the GMPE model gmpe = load_model(gmpe) # Generic context rctx = RuptureContext() # Make sure that site parameter values are converted to numpy arrays site_parameters_copy = site_parameters.copy() for k, v in site_parameters_copy.items(): site_parameters_copy[k] = np.array([site_parameters_copy[k]]) rctx.__dict__.update(site_parameters_copy) # Filter by arrivals that have significant expected PGA using GMPE is_significant = [] for eqid, arrival_time in arrivals.items(): event = next(event for event in catalog if event.id == eqid) # Set rupture parameters rctx.__dict__.update(rupture_parameters) rctx.mag = event.magnitude # TODO: distances should be calculated when we refactor to be # able to import distance calculations rctx.repi = np.array([ gps2dist_azimuth( st[0].stats.coordinates.latitude, st[0].stats.coordinates.longitude, event.latitude, event.longitude, )[0] / 1000 ]) rctx.rjb = rctx.repi rctx.rhypo = np.sqrt(rctx.repi**2 + event.depth_km**2) rctx.rrup = rctx.rhypo rctx.sids = np.array(range(np.size(rctx.rrup))) pga, sd = gmpe.get_mean_and_stddevs(rctx, rctx, rctx, imt.PGA(), []) # Convert from ln(g) to %g predicted_pga = 100 * np.exp(pga[0]) if predicted_pga > (pga_factor * recorded_pga): is_significant.append(True) else: is_significant.append(False) significant_arrivals = arrivals[is_significant] if significant_arrivals.empty: return st # Check if any of the significant arrivals occur within the signal_length = st[0].stats.endtime - signal_window_starttime cutoff_time = signal_window_starttime + pct_window_reject * (signal_length) if (significant_arrivals < cutoff_time).any(): for tr in st: tr.fail("A significant arrival from another event occurs within " "the first %s percent of the signal window" % (100 * pct_window_reject)) # Otherwise, trim the stream at the first significant arrival else: for tr in st: signal_end = tr.getParameter("signal_end") signal_end["end_time"] = significant_arrivals[0] signal_end["method"] = "Trimming before right another event" tr.setParameter("signal_end", signal_end) cut(st) return st
def signal_end( st, event_time, event_lon, event_lat, event_mag, method=None, vmin=None, floor=None, model=None, epsilon=2.0, ): """ Estimate end of signal by using a model of the 5-95% significant duration, and adding this value to the "signal_split" time. This probably only works well when the split is estimated with a p-wave picker since the velocity method often ends up with split times that are well before signal actually starts. Args: st (StationStream): Stream of data. event_time (UTCDateTime): Event origin time. event_mag (float): Event magnitude. event_lon (float): Event longitude. event_lat (float): Event latitude. method (str): Method for estimating signal end time. Either 'velocity' or 'model'. vmin (float): Velocity (km/s) for estimating end of signal. Only used if method="velocity". floor (float): Minimum duration (sec) applied along with vmin. model (str): Short name of duration model to use. Must be defined in the gmprocess/data/modules.yml file. epsilon (float): Number of standard deviations; if epsilon is 1.0, then the signal window duration is the mean Ds + 1 standard deviation. Only used for method="model". Returns: trace with stats dict updated to include a stats['processing_parameters']['signal_end'] dictionary. """ # Load openquake stuff if method="model" if method == "model": dmodel = load_model(model) # Set some "conservative" inputs (in that they will tend to give # larger durations). rctx = RuptureContext() rctx.mag = event_mag rctx.rake = -90.0 rctx.vs30 = np.array([180.0]) rctx.z1pt0 = np.array([0.51]) dur_imt = imt.from_string("RSD595") stddev_types = [const.StdDev.TOTAL] for tr in st: if not tr.hasParameter("signal_split"): continue if method == "velocity": if vmin is None: raise ValueError('Must specify vmin if method is "velocity".') if floor is None: raise ValueError('Must specify floor if method is "velocity".') epi_dist = (gps2dist_azimuth( lat1=event_lat, lon1=event_lon, lat2=tr.stats["coordinates"]["latitude"], lon2=tr.stats["coordinates"]["longitude"], )[0] / 1000.0) end_time = event_time + max(floor, epi_dist / vmin) elif method == "model": if model is None: raise ValueError('Must specify model if method is "model".') epi_dist = (gps2dist_azimuth( lat1=event_lat, lon1=event_lon, lat2=tr.stats["coordinates"]["latitude"], lon2=tr.stats["coordinates"]["longitude"], )[0] / 1000.0) # Repi >= Rrup, so substitution here should be conservative # (leading to larger durations). rctx.rrup = np.array([epi_dist]) rctx.sids = np.array(range(np.size(rctx.rrup))) lnmu, lnstd = dmodel.get_mean_and_stddevs(rctx, rctx, rctx, dur_imt, stddev_types) duration = np.exp(lnmu + epsilon * lnstd[0]) # Get split time split_time = tr.getParameter("signal_split")["split_time"] end_time = split_time + float(duration) else: raise ValueError('method must be either "velocity" or "model".') # Update trace params end_params = { "end_time": end_time, "method": method, "vsplit": vmin, "floor": floor, "model": model, "epsilon": epsilon, } tr.setParameter("signal_end", end_params) return st