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Coordinate conversion#

Utility script for coordinate conversion (and export) from SEG-Y file(s).

Description#

This utility script reproject (i.e. transforms) coordinates read from SEG-Y header(s) to different coordinate reference systems (CRS). The coordinate transformation is conducted using the Python package pyproj, an interface to the well-kown and established PROJ library. Input and output CRS can be specified as either EPSG codes (e.g., EPSG:4326) or PROJ.4 strings:

+proj=longlat +datum=WGS84 +no_defs

Suitable coordinate reference system

A projected CRS is required for most subsequent processing steps (e.g. UTM)!

Usage#

This script is designed to be used from the terminal (i.e. command line).

Command line interface#

The script can handle three different inputs:

  1. single SEG-Y file (e.g., filename.sgy)
  2. datalist of files to process (e.g., datalist.txt)
  3. directory with input files (e.g., /input_dir)

There are two options to run the script. We recommend using the CLI entry point like:

>>> 02_reproject_segy {filename.sgy | datalist.txt | </directory>} [optional parameters]

Alternatively, the script can be executed using the (more verbose) command:

>>> python -m pseudo_3D_interpolation.reproject_segy {filename.sgy | datalist.txt | </directory>} [optional parameters]

Optionally, the following parameters can be specified:

  • --help, -h: Show help.
  • --crs_src: Input coordinate reference system. Indicate using EPSG code or PROJ.4 string (e.g. "epsg:4326").
  • --crs_dst: Output coordinate reference system. Indicate using EPSG code or PROJ.4 string (e.g. "epsg:32760").
  • --output_dir {DIR}: Output directory (either --inplace or --output_dir are required!).
  • --inplace: Replace input data without creating copy (either --inplace or --output_dir are required!).
  • --suffix {sgy}: File suffix (default: sgy). Only used if directory is specified.
  • --filename_suffix {SUFFIX}: Filename suffix (e.g. pad, static) to filter input files. Only used if directory is specified.
  • --txt_suffix {despk}: Suffix to append to output filename (default: despk).
  • --scaler: Output coordinate scaler (following SEG-Y specification, default: -100).
    • negative: division by absolute value
    • positive: multiplication by absolute value
  • --src_coords: Byte position of input coordinates in SEG-Y file(s).
    • source: (73, 77)
    • group: (81, 85)
    • CDP: (181, 185)
  • --dst_coords: Byte position of output coordinates in SEG-Y file(s).
  • --verbose {LEVEL}, -V: Level of output verbosity (default: 0).
Last update: Monday, 03 July 2023 at 09:46:51