Data Formats

SeisGo uses a small set of structured data objects and file formats throughout its pipeline.

File formats

ASDF (.h5)

The primary on-disk format is ASDF (Adaptable Seismic Data Format), a self-describing HDF5 container that stores waveforms alongside station metadata (StationXML). SeisGo reads and writes ASDF files via pyasdf.

ASDF files are used for:

• Raw waveform archives

• FFT intermediate products

• Cross-correlation output

• dv/v monitoring output

Pickle (.pk)

Lightweight serialization for intermediate results and clustering outputs. Useful for quick experimentation but not recommended for long-term archival.

CSV (.csv)

Plain text output for anisotropy measurements (beamforming results, anisotropy parameters) and cluster map DataFrames.

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In-memory data types (seisgo.types)

FFTData

Holds the frequency-domain representation of one station–component time series, ready for cross-correlation.

Key attributes:

Attribute	Description
data	2-D complex array (n_windows, n_freqs)
dt	Sampling interval (s)
std	Per-window standard deviation
time	Window start times (UTCDateTime)
freq	Frequency vector (Hz)
win_len	Analysis window length (s)
step	Window step / overlap (s)
net, sta, loc, chan	SEED channel identifiers

CorrData

Stores a time-lag cross-correlation function (or autocorrelation) between a station pair over multiple time windows.

Key attributes:

Attribute	Description
data	2-D array (n_windows, n_lags)
dt	Sampling interval (s)
lag	Maximum lag (s)
dist	Inter-station distance (km)
cc_comp	Component pair, e.g. "ZZ", "RR"
side	"a" (both), "n" (negative), "p" (positive)
sta	[source_name, receiver_name]
time	Window timestamps
misc	Dictionary of auxiliary metadata

Useful methods:

corrdata.stack(method="linear")      # collapse to a single stack
corrdata.filter(fmin, fmax)          # bandpass filter in-place
corrdata.plot()                      # quick visualization
corrdata.to_asdf(outfile)            # save to ASDF

DvvData

Stores dv/v measurements derived from a CorrData object.

Key attributes:

Attribute	Description
dvv	dv/v values array
err	Measurement error / uncertainty
cc	Cross-correlation coefficient of each measurement
time	Time vector of measurements
freq	Frequency bands
method	Method used ("wts" or "ts")
cc_comp	Component pair

Useful methods:

dvvdata.plot()
dvvdata.to_asdf(outfile)

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Xcorr output structure options

When saving cross-correlations with noise.do_xcorr, the subdirectory layout is controlled by the output_structure parameter. Available options (from helpers.xcorr_output_structure()):

Option	Short	Layout
raw	r	By time chunk, all pairs together
source	s	Subfolder per virtual source
station-pair	sp	Subfolder per station pair
station-component-pair	scp	Nested source / component folders

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Stacking methods

Available methods (from helpers.stack_methods()):

linear, pws, tf-pws, robust, acf, nroot, selective, cluster

See Stacking API for parameter details.

Cross-correlation methods

Available methods (from helpers.xcorr_methods()):

xcorr, deconv, coherency