# 5.2. catalog_to_dd

This module contains functions to convert seisan catalogue to files to hypoDD input files.

These functions will generate both a catalogue (dt.ct) file, event file (event.dat), station information file (station.dat), and a correlation oiutput file correlated every event in the catalogue with every other event to optimize the picks (dt.cc).

The correlation routine relies on obspy’s xcorr_pick_correction function from the obspy.signal.cross_correlation module. This function optimizes picks to better than sample accuracy by interpolating the correlation function and finding the maximum of this rather than the true maximum correlation value. The output from this function is stored in the dt.cc file.

Information for the station.dat file is read from SEISAN’s STATION0.HYP file

Earthquake picks and locations are taken from the catalogued s-files - these must be pre-located before entering this routine as origin times and hypocentre locations are needed for event.dat files.

copyright: | EQcorrscan developers.
license: | GNU Lesser General Public License, Version 3 (https://www.gnu.org/copyleft/lesser.html)

## 5.2.1. Classes & Functions

`readSTATION0` | Read a Seisan STATION0.HYP file on the path given.
`read_phase` | Read hypoDD phase files into Obspy catalog class.
`sfiles_to_event` | Write an event.dat file from a list of Seisan events
`write_catalog` | Generate a dt.ct for hypoDD for a series of events.
`write_correlations` | Write a dt.cc file for hypoDD input for a given list of events.
`write_event` | Write obspy.core.event.Catalog to a hypoDD format event.dat file.