cube_conversion

This command-line tool converts DiGOS DATA-CUBE³ files into miniSEED files of a desired length of time with specified metadata. Output miniSEED files are ready for IRIS upload and have units of Pa. The tool can differentiate between channels for 3 channel DATA-CUBE³ files and optionally extract coordinates from the digitizer's GPS. The code only looks for files from digitizers defined in the digitizer_sensor_pairs.json file. Therefore, this file must be updated if pairings change or new pairings are added. The user can specify a custom "breakout box factor" for setups that modify the signal voltage via a voltage divider. This tool is currently only set up for conversion of infrasound data, but future updates will accommodate seismic as well.

Installation

It's recommended that you run this script within a new or pre-existing conda environment. (If you choose the latter option, ensure that your environment contains all of the packages listed in the Dependencies section.)

To create a new conda environment for use with this and other uafgeotools packages, execute the following terminal command:

$ conda create -n uafinfra -c conda-forge obspy

This creates a new environment called uafinfra with ObsPy and its dependencies installed.

You must also install GIPPtools and add it to your path as described in the Dependencies section.

To install cube_conversion, simply execute the following terminal command:

$ git clone https://github.com/uafgeotools/cube_conversion.git

Dependencies

Python packages:

• ObsPy

...and its dependencies, which you don't really have to be concerned about if you're using conda!

You also need to install GIPPtools and add it to your PATH.

• Version 2015.225 or newer is required.

• Add GIPPtools to your PATH by adding the following line to your ~/.bash_profile or ~/.bashrc:

  export PATH=$PATH:/path/to/gipptools-****.***/bin
  

Supplemental files

• digitizer_sensor_pairs.json — UAF digitizer-sensor pairs (EDIT ME!)

• digitizer_offsets.json — Digitizer offsets in V (We have found that each digitizer has a slight voltage offset from zero)

• sensor_sensitivities.json — Infrasound sensor sensitivities in V/Pa

Usage

To print the script's help menu, execute the following terminal commands:

$ conda activate uafinfra  # Or your pre-existing env
$ python /path/to/cube_convert.py --help

The help menu is shown below.

usage: cube_convert.py [-h] [-v] [--grab-gps]
                       [--bob-factor BREAKOUT_BOX_FACTOR]
                       input_dir [input_dir ...] output_dir network station
                       {01,02,03,04,AUTO} {AUTO,BDF,HDF,CDF}

Convert DATA-CUBE files to miniSEED files while trimming, adding metadata, and
renaming. Optionally extract coordinates from digitizer GPS.

positional arguments:
  input_dir             one or more directories containing raw DATA-CUBE files
                        (all files must originate from a single digitizer)
                        [wildcards (*) supported]
  output_dir            directory for output miniSEED and GPS-related files
  network               desired SEED network code (2 characters, A-Z)
  station               desired SEED station code (3-4 characters, A-Z & 0-9)
  {01,02,03,04,AUTO}    desired SEED location code (if AUTO, choose
                        automatically for 3 channel DATA-CUBE files)
  {AUTO,BDF,HDF,CDF}    desired SEED channel code (if AUTO, determine
                        automatically using SEED convention [preferred])

optional arguments:
  -h, --help            show this help message and exit
  -v, --verbose         enable verbosity for GIPPtools commands
  --grab-gps            additionally extract coordinates from digitizer GPS
  --bob-factor BREAKOUT_BOX_FACTOR
                        factor by which to divide sensitivity values (for
                        custom breakout boxes [4.5 for UAF DATA-CUBEs])

For example, the command

$ python cube_convert.py ~/data/raw/*/ ~/data/mseed/ AV GAIA 01 AUTO --grab-gps --bob-factor 4.5

means "convert all files in the subdirectories of ~/data/raw/ and place in ~/data/mseed/ with network code AV, station code GAIA, location code 01, and an automatically determined channel code, dividing the sensitivity by 4.5 and extracting coordinates from the digitizer's GPS."

A note on SEED band codes

Appendix A of the SEED manual (version 2.4) specifies the following guidance for band codes. Band codes are the first letter of the channel code; e.g., the "B" in "BDF".

Band code	Band type	Sample rate (Hz)	Corner period (s)
F		≥ 1000 to < 5000	≥ 10
G		≥ 1000 to < 5000	< 10
D		≥ 250 to < 1000	< 10
C		≥ 250 to < 1000	≥ 10
E	Extremely short-period	≥ 80 to < 250	< 10
S	Short-period	≥ 10 to < 80	< 10
H	High broadband	≥ 80 to < 250	≥ 10
B	Broadband	≥ 10 to < 80	≥ 10
M	Mid-period	> 1 to < 10
L	Long-period	≈ 1
V	Very long-period	≈ 0.1
U	Ultra long-period	≈ 0.01
R	Extremely long-period	≥ 0.0001 to < 0.001

Note that the band code depends on both the sample rate of the digitizer and the corner period of the sensor. In cube_convert.py we allow for "B", "H", or "C", which covers a range of sample rates from 10 to 1000 Hz, all for corner periods of 10 s or greater. While this covers most infrasound sensors, please confirm that your digitizer sample rate and sensor corner period fit into the above framework.

Authors

(Alphabetical order by last name.)

David Fee
Julia Gestrich
Alex Iezzi
Kathleen McKee
Liam Toney