.. _scanloc-spicker: Advanced S-Phase Detector ========================= The :ref:`scanloc` package provides the enhanced S-phase detectors, S-AIC and S-AIC-V, as well as the :ref:`debugger`. Overview -------- The *scanloc* package includes two S phase pickers: S-AIC and S-AIC-V, enhancing the performance of the picker with respect to the OpenSource S-L2. Both picker apply an AIC algorithm in order to detect S phases after a P pick was maked. Therefore S phases are only detected after a P detection. Using the S-AIC, S picks are determined on the vectorial sum of the horizontal componentes (L2 trace). The S-AIC-V works like the S-AIC but it picks S phases on the vertical component. The method which was applied to make the pick can be read * In the method column of the arrival table in the Location tab of :cite:t:`scolv`, * In the picker window from the letter within brackets following a phase type, * In the picker window from the hint which appears when hovering over a pick. .. _scanloc-fig-picker-method: .. figure:: ./media/scolv-picker-method.png :align: center :width: 10cm Read the method applied to make a pick in the arrival table of scolv or in the picker window. The performance of the pickers have been tested by comparison of automatic with manual picks (see the :ref:`Figure showing the comparison`). .. _scanloc-fig-picker-comparison: .. figure:: ../apps/media/hist_comp_vgt.png :align: center :width: 10cm Performance comparison showing the differences in pick time from manual picks and the optimally tuned pickers S-L2, S-AIC and S-AIC-V for local earthquakes in West-Bohemia/Vogtland. The area is typical of local earthquake monitored at short epicentral distances of a few tens of kilometers. The distribution of the differences in the automatic pick times with respect to the manual ones shows the increased performance using the S-AIC. Picker configuration -------------------- 1. **Global module parameters:** Add the plugin *saic* to the configuration of :program:`scautopick` or the global module configuration for making use of the S-AIC or the S-AIC-V: .. code-block:: sh plugins = ${plugins},saic #. **Module parameters:** Activate one of the S-phase ickers (S-L2, S-AIC, S-AIC-V) by changing the name of the S picker in the module configuration of :program:`scautopick`. Deactivating *killPendingSPickers* will allow to pick S phases even if more P phases were detected before: .. code-block:: sh spicker = "S-AIC" killPendingSPickers = false #. **Bindings parameters:** Configure the S-picker parameters under *spicker* in global section of the bindings of :program:`scautopick` e.g. for *S-AIC* in local earthquake monitoring. For tuning the values based on actual data you may use the :ref:`graphical debugger `: .. code-block:: sh detecFilter = "RMHP(10)>>ITAPER(30)>>BW(4,4,20)>>STALTA(0.2,20)" timeCorr = 0 spicker.AIC.noiseBegin = -10 spicker.AIC.signalBegin = 0.5 spicker.AIC.filter = "ITAPER(4)>>BW_HP(4,3)" spicker.AIC.detecFilter = "" spicker.AIC.step = 0.5 spicker.AIC.minSNR = 5 spicker.AIC.minCnt = 5 The AIC parameters *spicker.AIC.* are used for *S-AIC* and for *S-AIC-V*. The parameters of the S-phase pickers can be configured in the global section of the bindings profile of :program:`scautopick`. The meaning of some parameters are shared between the S-phase pickers: .. _scanloc-table-parameter: .. csv-table:: :header: "Parameter", "Picker type", "Description" :widths: 15,25,60 ":confval:`noiseBegin`","S-AIC, S-AIC-V, S-L2","Data window added before the p pick on order to compensate for effects due to the data processing, filtering and to compute the SNR." ":confval:`signalBegin`","S-AIC, S-AIC-V, S-L2","Start of the data processing relative to the reference P pick." ":confval:`signalEnd`","S-AIC, S-AIC-V, S-L2","End of the data processing relative to the reference P pick." ":confval:`filter`","S-AIC, S-L2","Filter applied before forming the L2 trace." ":confval:`detectFilter`","S-AIC, S-AIC-V, S-L2","Filter applied on the L2 trace before AIC analysis." ":confval:`step`","S-AIC, S-AIC-V","Step size in which the time windows are enlarged." ":confval:`minSNR`","S-AIC, S-AIC-V, S-L2","Minimum SNR in order to accept a pick." ":confval:`minCnt`","S-AIC, S-AIC-V","Minimum number the AIC minimum must be found for subsequent time windows." ":confval:`uncertainty`","S-AIC, S-AIC-V","Pick uncertainty. Unused by the picker but part of the output pick element." .. _scanloc-spick-debugger: Picker tuning: Debugger ----------------------- The :ref:`debugger GUI` allows the graphics-assisted tuning of the S pickers, S-L2, S-AIC, S-AIC-V. In order to make use of the S picker debugging GUI: #. **Global module parameters:** Add the plugin *spickdbg* to the global configuration of :cite:t:`scolv` (:file:`scolv.cfg`) .. code-block:: params plugins = ${plugins}, spickdbg #. **Global bindings:** Configure the initial parameters in the global bindings of the considered stream. You may adopt parameters from the ones used by the *spicker* for a good inital guess. The debugger GUI can be started from the picker window of :program:`scolv`. If there is an existing P pick, the debugger window can be opened with a right click on the P pick. In the dropdown menu the S picker type can be chosen. .. _scanloc-fig-picker-debugger-menu: .. figure:: ./media/scolv-picker-debugger-open.png :align: center :width: 10cm Selection of S-picker debugger by right-clicking on a P phase. A new pop-up window opens where the P pick (red line) and the newly determined S pick (light blue line) are shown and the parameters can be tested. .. _scanloc-fig-debugger: .. figure:: ./media/s-picker-debugger.png :align: center :width: 10cm S-picker debugger example showing the filtered horizontal traces, the computed L2 trace and the resulting S pick (light blue line). The :ref:`example above ` shows the debugger GUI for a local earthquake: * **Top traces:** original filtered data. * **Bottom trace:** Resulting trace e.g. L2. * **First red line:** the time of the referenced pick. A pick pick should be selected. * **Additional phase picks** are shown on top of the data. * **Light blue line:** the S pick which would be made based on the selected parameters. The number next to 'AIC' indicates the SNR. * **Lower section:** Parameters which can be adjusted. The initial parameters are read from the global binding configuration from the selected stream. Change the parameters to find the optimum values. Click on the *Update* button to apply them in the GUI. In order to make use of the tested parameters their values must be configured in the bindings parameter of :program:`scautopick` or the respective alias. .. _scanloc-debugger-parameters: .. csv-table:: :header: "Parameter", "Description" :widths: 15,85 "N","Start of the noise window" "S0","Start of the AIC window" "S1","End of the AIC window" "AIC0","Start of the data processing relative to the reference P pick." "AIC","S pick based on the current parameters with number indicating the SNR." "AIC1","End of the data processing when meeting MinSNR and MinCnt." "Pick","Pick time at AIC."