NanoseismicSuite

The NanoseismicSuite consists of different Java modules for waveform data processing, event detection and event localization. It is specialized for large continuous seismological datasets with many stations and low-SNR events. It is the official software for the CTBT On-Site Inspections Seismic Aftershock Monitoring System (OSI-SAMS).

The modules are:

SeisServ:
SeisServ reads seismic data and meta-data in the Center for Seismic Studies (CSS) or MiniSEED format from
files or an SQL database. It provides this data to the other
modules and allows editing of the meta-data, e.g. the geometry of seismic stations.

SonoView
After loading the data, SonoView is the first application to use in a
typical event screening scenario to detect low-SNR events. It visualizes so called super-sonograms which
are noise-adapted spectrograms combined from multiple stations of seismic arrays. These super-sonograms
help to find short (few seconds) and low-magnitude (e.g. ML -2.0) seismological events with low signal-to-noise ratios
in a manner that maximizes the visible data on one screen. An arbitrary amount
of mini-arrays and time spans can be loaded. An analyst can scroll fast
through the continuous data in SonoView and mark suspicious events for further processing steps.
Further methods include e.g. noise analysis by means of the 95th percentile and bandpass filtering, spectrum calculation,
listening to seismic events, automatic detection by coincidence STA/LTA, resampling and the export of data for further processing.

TraceView
Detected events from SonoView can be further analyzed in TraceView which
visualizes the seismograms of these events together with a map of the
measurement area with locations of the seismic stations. It provides a
two-dimensional neighbourhood overview of mini-arrays which can not be provided
by the one-dimensional listing of SonoView.
TraceView shows the seismograms of the currently selected station
and the five adjacent stations based on geographic context.
Basic filters and scalings can be applied to the seismograms, seimological detection threshold maps
based on the noise levels at individual stations can be displayed and
geo-referenced images of the measurement area can be shown in the map (e.g. satellite images).

HypoLine
The last application in the processing pipeline of the NanoseismicSuite is HypoLine which is
used for the localization and magnitude estimation of events. Accurate three-dimensional underground
models of the measurement area are often not known a priori and localization is
done by time difference of arrival (TDOA) hyperbolae and S-P distance circles
based on one-dimensional velocity models.
HypoLine allows a localization and identification with interactive and graphical techniques
for very weak events, where the influence of each parameter to event-location
is displayed in real-time in the solution space.

SonoDet
SonoDet is an additional module used for the automatic detection and classification of low-SNR events by pattern recognition of adapted spectrograms.
In the supervised mode SonoDet scans seismological datasets with a sliding window for the recurrence of signals similar to previously labeled signals. In the unsupervised mode, events detected by a coincidence STA/LTA trigger can be clustered by similarity and prototypes of each event cluster can be visualized with Self-organizing Maps. Multiple methods are available for pattern comparison which can be interactively tested.

References:
Joswig, M. (2008). Nanoseismic monitoring fills the gap between microseismic networks and passive seismic. First Break, 26, 117–124.

Sick, B., Walter, M., & Joswig, M. (2012). Visual Event Screening of Continuous Seismic Data by Supersonograms. Recent Advances in Nuclear Explosion Monitoring Vol. 2 - Pure and Applied Geophysics, PAGEOPH. doi:10.1007/s00024-012-0618-x

Sick, B., Walter, M., & Joswig, M. (2013). Near-surface fracture and impact discovery from landslides and sinkholes by sonogram screening, First Break, 31, 95–101.