Command-Line Usage¶

Introduction¶

segy comes with a useful CLI tool to interrogate SEG-Y files either on disk or any remote store.

Command Line Usage¶

SEG-Y provides a convenient command-line-interface (CLI) to do various tasks.

For each command / subcommand you can provide --help argument to get information about usage.

At the highest level, the segy command line offers various options to choose from. Below you can see the usage for the main entry point.

Dumping Data¶

When we use segy dump subcommand, we have some options to choose from. As usual, the uri (local or remote paths) will allow us to use the same toolkit for local and cloud / web files.

For the CLI demos, we will use a public SEG-Y file over HTTPS.

This file is one shot record from the Soda Lake 2010 3D/3C survey on the Geothermal Data Repository (CC-BY-4.0).

We will take a look at field record F7733R1.SGY (shot 7733). No credentials and no storage_options are required. {"anon": true} is an S3 option and breaks this HTTPS URL.

Basic Info¶

We can output a basic summary of the file using the info command.

$ segy dump info \
    https://gdr-data-lake.s3.us-west-2.amazonaws.com/soda_lake/raw_seismic/2010/v1.0.0/F7733R1.SGY
{
  "uri": "https://gdr-data-lake.s3.us-west-2.amazonaws.com/soda_lake/raw_seismic/2010/v1.0.0/F7733R1.SGY",
  "segyStandard": 0.0,
  "numTraces": 958,
  "samplesPerTrace": 2000,
  "sampleInterval": 2000,
  "fileSize": 7897520
}

File Text Header¶

Let’s take a look at the text header.

$ segy dump text-header \
    https://gdr-data-lake.s3.us-west-2.amazonaws.com/soda_lake/raw_seismic/2010/v1.0.0/F7733R1.SGY
C 1 CLIENT                        COMPANY                       CREW NO
C 2 LINE            AREA                        MAP ID
C 3 REEL NO           DAY-START OF REEL     YEAR      OBSERVER
C 4 INSTRUMENT: MFG            MODEL            SERIAL NO
C 5 DATA TRACES/RECORD        AUXILIARY TRACES/RECORD         CDP FOLD
C 6 SAMPLE INTERVAL         SAMPLES/TRACE       BITS/IN      BYTES/SAMPLE
C 7 RECORDING FORMAT        FORMAT THIS REEL        MEASUREMENT SYSTEM
C 8 SAMPLE CODE: FLOATING PT     FIXED PT     FIXED PT-GAIN     CORRELATED
C 9 GAIN  TYPE: FIXED     BINARY     FLOATING POINT     OTHER
C10 FILTERS: ALIAS     HZ  NOTCH     HZ  BAND     -     HZ  SLOPE    -    DB/OCT
C11 SOURCE: TYPE            NUMBER/POINT        POINT INTERVAL
C12     PATTERN:                           LENGTH        WIDTH
C13 SWEEP: START     HZ  END     HZ  LENGTH      MS  CHANNEL NO     TYPE
C14 TAPER: START LENGTH       MS  END LENGTH       MS  TYPE
C15 SPREAD: OFFSET        MAX DISTANCE        GROUP INTERVAL
C16 GEOPHONES: PER GROUP     SPACING     FREQUENCY     MFG          MODEL
C17     PATTERN:                           LENGTH        WIDTH
C18 TRACES SORTED BY: RECORD     CDP     OTHER
C19 AMPLITUDE RECOVERY: NONE      SPHERICAL DIV      AGC     OTHER
C20 MAP PROJECTION                      ZONE ID       COORDINATE UNITS
C21 PROCESSING:
C22 PROCESSING:
C23
C24
C25
C26
C27
C28
C29
C30
C31
C32
C33
C34
C35
C36
C37
C38
C39
C40 END EBCDIC

File Binary Header¶

$ segy dump binary-header \
    https://gdr-data-lake.s3.us-west-2.amazonaws.com/soda_lake/raw_seismic/2010/v1.0.0/F7733R1.SGY
{
  "job_id": 18909,
  "line_num": 1,
  "reel_num": 1,
  "data_traces_per_ensemble": 957,
  "aux_traces_per_ensemble": 1,
  "sample_interval": 2000,
  "orig_sample_interval": 2000,
  "samples_per_trace": 2000,
  "orig_samples_per_trace": 2000,
  "data_sample_format": 1,
  "ensemble_fold": 0,
  "trace_sorting_code": 1,
  "vertical_sum_code": 1,
  "sweep_freq_start": 0,
  "sweep_freq_end": 0,
  "sweep_length": 0,
  "sweep_type_code": 4,
  "sweep_trace_num": 0,
  "sweep_taper_start": 0,
  "sweep_taper_end": 0,
  "taper_type_code": 3,
  "correlated_data_code": 1,
  "binary_gain_code": 2,
  "amp_recovery_code": 1,
  "measurement_system_code": 2,
  "impulse_polarity_code": 0,
  "vibratory_polarity_code": 0,
  "segy_revision_major": 0,
  "segy_revision_minor": 0
}

Trace Header¶

This is how we can get three header fields for a few traces.

$ segy dump trace-header https://gdr-data-lake.s3.us-west-2.amazonaws.com/soda_lake/raw_seismic/2010/v1.0.0/F7733R1.SGY \
    --index 100 --index 101 --index 500 --index 501 \
    --field source_coord_x --field source_coord_y \
    --field group_coord_x --field group_coord_y \
    --field coordinate_scalar
             source_coord_x  source_coord_y  group_coord_x  group_coord_y  coordinate_scalar
trace_index
100                 7735193        45340080        7747690       45337925                 -1
101                 7735193        45340080        7748244       45337549                 -1
500                 7735193        45340080        7745319       45347606                 -1
501                 7735193        45340080        7745874       45347232                 -1

Configuration Options¶

The examples above use public HTTPS. Do not set SEGY_STORAGE_OPTIONS for that URL.

When accessing public datasets from S3, we need to set SegySettings().storage_options = {"anon": True} for anonymous access. SegySettings exposes all configuration options as environment variables. We just need to set storage_options with the JSON string {"anon": true}. On Linux you can do this by the command below. Environment variables can be configured in many ways, please refer to the options for your specific Operating System (OS).

export SEGY_STORAGE_OPTIONS='{"anon": true}'