Snapshots
What a snapshot captures
A snapshot saves the current processing parameters and quality metrics for an event at a point in time. Specifically, it stores:
- All event-level parameters: the time window, bandpass filter settings, and
Min CC (
min_cc, exposed in the CLI viapick cc) - Per-seismogram parameters for every seismogram in the event: the current
t1pick,selectflag, andflipflag - Quality metrics, if available at snapshot time:
- ICCS CC per seismogram (always present once the event has been opened)
- MCCC metrics per seismogram and the global RMSE (present only if MCCC has been run)
The seismogram waveform data itself is not copied — snapshots are lightweight. They capture where you are in the parameter space, not the data.
This works because the CC seismograms and context seismograms that ICCS operates on are entirely deterministic: given the original waveform data and a set of parameters, they are always reconstructed identically. Restoring a snapshot therefore restores the exact state of the ICCS instance — there is nothing lost by not saving the derived arrays.
If seismograms are added to the project after a snapshot was taken, they have no entry in that snapshot. When previewing or rolling back, those seismograms are included using their current live parameters — the snapshot's event-level parameters (window, filter, Min CC) still apply to them.
Snapshots are per-event. Each event maintains its own list.
When to take a snapshot
Take a snapshot before making changes you might want to undo:
- After importing data, before any processing — a clean baseline to return to
- After initial alignment looks good, before tightening parameters further
- Before trying an experimental configuration (different window, filter, etc.)
- Before running MCCC
Snapshots are cheap. Taking one costs almost nothing, and having a rollback point available is worth it.
Creating a snapshot
The comment is optional but useful for identifying the snapshot later.
Press n to open the snapshot comment dialog, optionally enter a comment,
and confirm. The new snapshot appears immediately in the Snapshots tab.
Click New Snapshot in the Processing tab. A dialog lets you enter an optional comment.
Listing snapshots
The table shows the snapshot ID, date and time, comment, and number of seismograms captured.
Snapshots for the current event are listed in the Snapshots tab.
Switch events using the event switcher (e) to see another event's
snapshots.
The Snapshots tab lists all snapshots for the selected event.
Inspecting a snapshot
Before rolling back, it can be useful to see what a snapshot contains.
details shows the event-level parameters (window, filter, min_ccnorm) as
they were when the snapshot was taken. preview builds the ICCS stack from
the snapshot's parameters and displays it — without modifying anything in
the database.
Press Enter on a snapshot row in the Snapshots tab to open the action
menu. Options include:
- Show details — displays the saved event parameters
- Preview stack — opens the stack plot built from the snapshot
- Preview matrix image — opens the matrix image
Both preview options support the context (c) and all seismograms
(a) toggles in the action menu before launching.
Select a snapshot in the Snapshots tab — its stack and matrix image are shown in the right panel in read-only mode.
Rolling back
Rolling back restores the snapshot's parameters as the current live values. This overwrites the current event and seismogram parameters for this event.
After rolling back, the event's parameters are exactly as they were when the snapshot was taken. Any ICCS runs or parameter changes made after that snapshot are undone. The snapshot itself is not deleted — you can roll back to it again.
If the snapshot contains MCCC quality data, the live quality metrics are restored from the best matching snapshot: the one whose parameter hash matches the restored state and that has the most recent MCCC data. In practice this is the snapshot you rolled back to, but if that snapshot predates any MCCC run, the most recent snapshot with the same parameters and MCCC data is used instead.
Deleting a snapshot
Deletion is permanent. The snapshot cannot be recovered after deletion.
Exporting snapshot data
For archiving or scripting purposes, snapshot data can be exported to JSON:
The output is a JSON object with five keys, all cross-referenced by
snapshot_id:
| Key | Contents | Always present? |
|---|---|---|
snapshots |
Snapshot metadata (ID, time, comment, hash) | Yes |
event_parameters |
Event parameter snapshots | Yes |
seismogram_parameters |
Per-seismogram parameter snapshots | Yes |
event_quality |
Event quality snapshots (MCCC RMSE) | Only if MCCC has been run |
seismogram_quality |
Per-seismogram quality snapshots (ICCS CC, MCCC metrics) | Only if quality metrics exist |