seisvelan

Interactive seismic normal-moveout velocity analysis.

Description

The seisvelan package provides an interactive GUI for picking seismic normal-moveout velocities on CMP gathers.

This little program is not meant to replace commercial seismic software optimized to run velocity analysis on large amounts of data. It's primarily meant for smaller projects in, for instance, academic environments to facilitate practical velocity picking in lectures, exercises or field practicals.

Key features

• Pure Python code based on tkinter, i.e., minimal external dependencies.
• Uses the seisio module for flexible I/O of seismic data.
• GUI allows users to interactively change clips, axis labels, axis ticks, colormaps, and many more parameters.
• OS-independent, i.e., should work on Linux, Windows, etc.

Getting Started

Dependencies

Required: matplotlib, numpy, seisio, tabulate, tkinter-tooltip, tkinter-icons[bootstrap]

The seisio packages requires: numba, numpy, pandas, tabulate

Installation

Install from PyPI:

$> pip install seisvelan

Afterwards, simply call

$> seisvelan

at the commandline. You can use option -v to obtain additional logging information or -vv to put all modules that use the standard logging facility into debug mode, including seisvelan itself.

Install directly from gitlab:

$> pip install git+https://gitlab.kit.edu/thomas.hertweck/seisvelan.git

Editable install from source:

This version is intended for experts who would like to test the latest version or make modifications. Normal users should prefer to install a stable version.

$> git clone https://gitlab.kit.edu/thomas.hertweck/seisvelan.git

Once you acquired the source, you can install an editable version of seisvelan with:

$> cd seisvelan
$> pip install -e .

An alternative location of the source is https://github.com/ThomasHertweck/seisvelan.

Overview

Here is a screenshot of the GUI with some explanations:

JSON output file

The JSON file produced by the interactive GUI can easily be read into Python:

import ast
import json
from sortedcontainers import SortedDict

def _extract_picks(json_pickdata):
    pos = []
    times_per_pos = []
    velos_per_pos = []
    etas_per_pos = []
    for p, pks in json_pickdata.items():
        pos.append(ast.literal_eval(p)[0])
        times_per_pos.append([val["t"] for val in pks])
        velos_per_pos.append([val["v"] for val in pks])
        etas_per_pos.append([val["e"] for val in pks])
    return pos, times_per_pos, velos_per_pos, etas_per_pos

def get_pickvalues_as_list(pick_file):
    with open(pick_file, "r", encoding="utf-8") as f:
        json_data = json.load(f)
    pickdata = json_data["picks"]
    if not pickdata:
        raise RuntimeError(f"JSON file {pick_file} seems to contain no picks.")
    pos, t, v, e = _extract_picks(pickdata)
    return  pos, t, v, e

def get_pickvalues_as_dict(pick_file):
    pos, t, v, e = get_pickvalues_as_list(pick_file)
    pdict = SortedDict()
    for i, key in enumerate(pos):
        pdict[key] = {"t": t[i], "v": v[i], "e": e[i]}
    return pdict

Testing

The current version of the seisvelan package has primarily been tested on Linux and Windows using Python 3.13 and 3.14.

Main author

Dr. Thomas Hertweck, geophysics@email.de

Citation

If you use the seisvelan package and you find it useful, getting some feedback would be very much appreciated. If you would like to cite this package, please use, for instance:

Hertweck, T. (2026). seisvelan: A Python GUI for interactive seismic velocity analysis. Version 0.1. url: https://gitlab.kit.edu/thomas.hertweck/seisvelan/ (visited on 08/25/2026).

Adjust year, version and last visited date as required. Here's a BibTeX entry:

@software{seisvelan,
  author  = {Hertweck, Thomas},
  year    = {2026},
  title   = {seisvelan: A Python GUI for interactive seismic velocity analysis},
  url     = {https://gitlab.kit.edu/thomas.hertweck/seisvelan/},
  urldate = {2026-08-25},
  version = {0.1.0}
}

License

This project is licensed under the GPL v3.0 License - see the LICENSE.md file for details