Maps and plots

All views follow the selection: selecting origins in the origin table highlights them on the map and in the plots, and the diagnostic plots always show the active origin.

Map panel

The Map panel. The views are tabs; the controls on the right are shared by all three views.

The panel has three Views - Map, Hexmap and 3D - and a column of controls on the right that applies to all of them:

Controls	Description
Animation	Steps through the origins in time order. Play starts or pauses the animation, the slider moves through it, Cumul. keeps the origins of earlier steps visible and Reset shows all origins again. The label next to Cumul. shows the time range currently shown.
Layers	Show or hide faults, symbols, the reference catalogue, cities, city labels, stations and station labels. Faults… loads faults (SeisComP XML or GeoJSON lines), which are also used for the Fault Q metric; Catalog… loads an external reference catalogue (FDSNWS text or CSV with time,lat,lon,depth), drawn as grey dots. The Reset next to each removes it again.
Clustering	Clustering of the origins shown: eps (neighbourhood radius), min size (minimum cluster size) and depth × (weight of depth in the distance). auto lets catalyst choose. Press Refresh to cluster again.

The reference cities come from the profile key cities or from cities in catalyst.cfg.

Map

The Map tab shows the origins, the stations and the picks. The active origin is the large star; lines connect it to its stations, whose triangles are coloured by the residual of their pick (red late, blue early, grey unused). Picks are drawn at their stations. Clicking a pick selects the origins it belongs to, and clicking a star selects that origin. Hover over a station to see its name, phase and residual.

Hexmap

The Hexmap tab shows the origins as a hexagon density map. Res sets the hexagon width in km, and Symbols overlays the epicentres and stations.

Each cell can show

• the number of events,

• the mean depth,

• the mean number of phases,

• the difference in the number of events between the catalogue and a loaded reference catalogue.

The cells can be limited to one time category: day or night (sun above or below the horizon at the epicentre), weekday or weekend (local date), summer (June to August) or winter. Comparing day and night or weekday and weekend maps helps to find quarry blasts and other man-made sources. A minimum count hides cells with fewer origins. A note on the map explains when a category contains no origins.

3D

The 3D tab shows the hypocentres in three dimensions, with topography if demPath is set. Faults, the reference catalogue and the origin clustering are set with the controls on the right of the panel (see above).

Todo

Screenshot: 3D view with faults and clustered origins (base/media/catalyst/3d.png).

Picks panel

Tab	Content
Table	All picks, sortable by every column. The context menu offers Copy, Save as CSV… and Delete pick(s).
Histogram	Number of picks over time. Click a bar to show only its picks; see Pick filters.
Beams	Array beams on a map: the back-azimuth of each array pick drawn from its station.
Slow/Baz	Slowness against back-azimuth of the array picks as a polar chart; selecting segments filters the picks. See below.
Baz/time	Back-azimuth of the array picks over time. Sources that are active repeatedly show up as horizontal lines.

The Beams and Slow/Baz tabs show the picks of the selected origins when origins are selected.

Slow/Baz

The Slow/Baz chart of an infrasound data set: all picks lie on the Is band.

The chart shows each array pick at its back-azimuth (angle, north up, clockwise) and its horizontal slowness (radius, logarithmic). The pick colour identifies the station; picks hidden by a filter are drawn grey.

The radius is divided into rings whose limits are written along the top edge in s/° and as trace velocity in km/s:

• the inner rings hold seismic picks (fast, below about 30 s/°),

• the Is band holds atmospheric infrasound, 0.30–0.45 km/s trace velocity (about 247–371 s/°, after the European Infrasound Bulletin),

• the outer ring holds slower detections, usually wind noise.

Each ring is cut into 15° sectors. The mouse actions are shown at the bottom of the chart:

• click a sector to select or deselect it,

• Shift+click selects or deselects a whole ring,

• right-click the Is band to change its limits.

Selected sectors act as a pick filter: only array picks inside them stay visible in the table and the other views, and only those are used for nucleation. Picks without a back-azimuth or slowness are not affected. The selection and the band limits appear in the pick filter dialog and are saved in the profile (pickIsTraceVelMin, pickIsTraceVelMax).

Baz/time

Back-azimuth over time. Repeating sources form horizontal bands.

The plot shows the back-azimuth of each array pick against its time. Only the picks visible in the pick table are drawn, so the pick filter and the Slow/Baz selection apply. Each station has its own colour, and the marker shape follows the phase (circle P, square S, triangle Is).

A source that is active repeatedly - a quarry, a mine, a test site - is seen from one array under nearly the same back-azimuth every time, so its picks line up as repeating sources: horizontal bands. A band that appears in several arrays at once points to the source; Match Slow/Baz (see Refining origins) uses this.

The summary in the upper left counts the picks and stations shown and the picks selected. Drag a rectangle to select its picks in the pick table (with Shift to add, Ctrl to remove); selected picks get a dark ring. Hover a marker to see its station, phase and time.

Origins panel

Tab	Content
Table	All origins with their quality metrics, see Quality metrics. The filter button opens the origin filters: latitude, longitude, depth, RMS, phase count, mismatch, status and whether the origin was updated.
Cumulative	Cumulative number of origins over time.
Wadati	Wadati diagram of the active origin: S−P time against the P time after the first P, for stations with both phases. The slope plus 1 is the vp/vs ratio; stations off the line point to a mispicked P or S.

Active origin panel

The plots of the active origin are the main tool for judging a location. All plots, the arrivals table and the pick plots draw a pick the same way: the shape gives the phase family, the colour its state.

Shape	Phase family
circle	P
square	S
triangle	Is (infrasound)

Fill / outline	State
red / red	used by the origin
white / red	associated, not used (weight 0)
blue / red	to be added (pending)
red / blue	to be removed (pending)
blue / blue	not associated

Unassociated picks can be box-selected and associated, and clicking a point toggles whether the arrival is used. Hover a marker to see its station, phase and time.

Tab	Content
Arrivals	The arrivals with residual, distance, azimuth and weight.
Distance	Residual against distance.
Azimuth	Residual against azimuth. A trend with azimuth points to a mislocation.
Baz residual	For array picks: measured minus predicted back-azimuth against azimuth, with the pick uncertainty as error bars.
Travel-time	Picks against distance with the P and S travel-time curves and their tolerance bands. This is the plot the analyst rules are based on.
Move-out	Reduced travel time (T − d/V) against distance per phase family, with the apparent-velocity fit. See below.
Polar	Plan view of the stations around the epicentre. The azimuthal gap is easiest to see here.

Baz residual

Back-azimuth residuals of three array picks, all within the tolerance.

For each array pick of the active origin the plot shows the residual - the measured back-azimuth minus the direction from the station to the epicentre - against the azimuth of the station seen from the epicentre. The error bars are the back-azimuth uncertainty of the pick (asymmetric if the pick has a lower and upper uncertainty).

The green tolerance band is ± Az tol of the back projection (see Back projection). Picks inside it agree with the epicentre. A single array far outside points to a wrong association or a disturbed bearing; the Azimuth locator switches such an array off by itself when three or more arrays are available. A trend with azimuth points to a mislocation. If no arrival carries a back-azimuth, the plot says so.

Move-out

Move-out of an infrasound origin: three Is picks, the fitted line and the celerity band.

The move-out plot shows the reduced travel time T − d/V of the picks against distance. With V equal to the apparent velocity of the picks they line up horizontally, which makes outliers and wrong phases easy to see.

The controls select the phase Family (P, S or Is), set Reduce vel (V) and run Fit V. Fit V fits a straight line through the used picks of each family and writes the result to the fit readout: the apparent velocity with its uncertainty, the RMS and the number of picks. The selected family’s velocity becomes Reduce vel, and its fit line is drawn dashed, labelled with V and t0 - the time of the line at distance 0 relative to the origin time. A t0 far from 0 means the origin time does not fit the picks.

For P and S the theoretical travel-time curves of the selected model are drawn. For Is the celerity band is drawn instead: a wedge from the origin between 0.27 and 0.34 km/s celerity. Picks inside it are consistent with stratospheric or tropospheric propagation.

Travel-time

Travel time of three Is picks against distance, on the Is curve of the travel-time model.

The plot shows the travel time of each pick (pick time minus origin time) against the epicentral distance. The curves are the travel times of the selected model for the phases of the picks - P, S and their crustal branches, or the Is curve for infrasound. The shaded tolerance band around each curve is ± Assoc. tol: picks inside it are associated by Associate and kept by Deassociate.

Picks of the origin are drawn in their state colour; unassociated picks nearby are blue and can be selected with a rectangle and associated. This is the plot the analyst rules are based on.