Data Management

This section presents various aspects of preparation and data management techniques that should be followed during measurements.

Note

In the future this section should be moved somewhere outside of the crtomo_doc manual, but for now this seems like a good place.

Directory structure:

.
└── [CAMPAIGN_NAME]
        ├── Documenation
        ├── EIT
        │   ├── 20170710
        │   │   ├── p_01
        │   │   │   ├── Documentation
        │   │   │   ├── m_01_1005
        │   │   │   │   ├── Analysis
        │   │   │   │   ├── Data
        │   │   │   │   ├── Documentation
        │   │   │   │   ├── Pictures
        │   │   │   │   └── Readme.txt
        │   │   │   └── m_02_1305
        │   │   │       ├── Analysis
        │   │   │       ├── Data
        │   │   │       ├── Documentation
        │   │   │       ├── Pictures
        │   │   │       └── Readme.txt
        │   │   └── p_02
        │   │       ├── Documentation
        │   │       └── m_01_1503
        │   │           ├── Analysis
        │   │           ├── Data
        │   │           ├── Documentation
        │   │           ├── Pictures
        │   │           └── Readme.txt
        │   └── Documentation
        └── Readme.txt

Readme structure::

[general]
date = 20170710
time = 1005
person_responsible = Maximilian Weigand
person_email = mweigand@geo.uni-bonn.de
attending_persons = Micky Maus, Goofy
site = Dollendorf
area = S7
profile = profile 1
keywords = landslide,CMM slide
description_short = One sentence explanation
description = Put a comprehensive explanation of the experiment here. This
    explanation can span multiple lines!
measurement_type = EIT
survey_type = field
problems =
    Describe any problems during the measurements here
missing =
    Are any information missing? It's better to note problems here than to
    ignore them!
restrictions =
    How can we use the data? If data is measured in the Department of
    Geophysics, leave this field blank. Otherwise note the owner and any known
    usage rights.

Preparing the measurements

  • Make a rough plan of the analysis procedures
    • Which environment variables do you need to measure/capture?
    • How do your expected final results look like? Which plots comprise the final results?

During the measurements

  • Create sketches of the field site/laboratory setup containing electrodes, electrode numbers, (if possible: topography), and all other important objects/features (note also possible sources of error, e.g. cars or other metallic stuff)

After the measurements

  • Sort (and backup) data files.
  • Create Readme.txt files containing all important information (and/or references to additional documents).
  • Create text files containing electrode positions (x, z), z direction points upwards (topography).
  • Make a list of the data sets you want to process, i.e. which data sets to process individually and which to process together (e.g. normal-reciprocals).
  • Create the FE-grids for the subsequent analysis. Sometimes it is advisable to create a fine and a coarse grid. Initial data processing can be done using the coarse grid to save time.
  • Inspect the data and set filters.
  • Run preliminary inversions.
  • Make sure that you don’t have too large normal-reciprocal differences (not only in absolute, but also in relative values).
  • Regarding merged data sets: It is advisable to only use them if only normal-reciprocal pairs are used. Otherwise its possible that spectra get distored when only parts of the spectra are merged (i.e. averaged).