GEODYN
======

--------------

**geodyn** format
-----------------

The ``geodyn`` format is a common format for geophysical data files. The
file structure is simple, a *header* and the *data* section.

as an example, below a DEM (digital elevation model) is shown in the
``geodyn`` format:

.. code:: quote

   !--------------------------------------------------------------------
   !PROJECT: KARST Einhornhoehle
   !LOCATION: Einhornhoehle
   !DATA: DTM (Landesamt Niedersachsen)
   !OPERATOR:
   !DATE:
   !COORDINATES: UTM 32T
   !NOTES: 2m resolution (resampled), offset -44.90m substracted
   !--------------------------------------------------------------------
   !VALUE:     datetime    easting    northing    elev    depth          topo         value
   !UNIT:                      [m]         [m]     [m]      [m]           [m]          [xx]
   2019-01-11-18:00:00   596000.00  5722100.00  330.01     0.00        330.01          0.00
   2019-01-11-18:00:00   596002.00  5722100.00  330.04     0.00        330.04          0.00
   2019-01-11-18:00:00   596004.00  5722100.00  330.08     0.00        330.08          0.00
   2019-01-11-18:00:00   596006.00  5722100.00  330.11     0.00        330.11          0.00
   2019-01-11-18:00:00   596008.00  5722100.00  330.15     0.00        330.15          0.00

Lines starting with an ampersand (!) are comment lines. The capitalised
key words are used to sort the information in this header lines:

================= ======================================
keyword           description
================= ======================================
**!PROJECT:**     project name
**!LOCATION:**    locality
**!DATA:**        type of data, origin
**!OPERATOR:**    people responsible for data aquisition
**!DATE:**        date of data processing
**!COORDINATES:** coordinate system used
**!NOTES:**       additional notes
================= ======================================

The last two lines in the header are **VALUE** and **UNIT** for the
column data following.

All other lines are **data**, following the format

============== ======================================
field          description
============== ======================================
datetimestring date and time for proceesed data
easting        easting in UTM coordinates
northing       northing in UTM coordinates
elev           elevation
depth          depth of field value (sensor location)
value1         field value 1
value2         field value 2
============== ======================================

The ``geodyn`` format can hold any type of data, e.g. 1D borehole logs,
2D map view data (gravity, magnetic, self-potential, topography, …) and
2D cross section data (geoelectrics, georadar, …), or 3D data.

--------------

From ERT to **geodyn**
----------------------

Within *Res2DInv*, use the display window to display data, then export
with swapped depth axis. The resulting ``name.xyz``-file will hold the
exported data. From the many formats, use the blocks without topography
section, and save as *name.blocks*

Together with the profile data *name.profile* use the program
``ERT_Res2DInv2GEODYN`` to create a file in geodyn format.

--------------

From GPR to **geodyn**
----------------------

Within *ReflexW*, export the processed profiles as ascii 4 colunm format
(use traceheader coordinates!). The resulting file ``name.ASC`` holds
the coordinates, two-way traveltime, and reflection amplitudes.

Together with the profile data *name.utm* use the program
``GPR_REFLEXW2GEODYN`` to create a file in geodyn format. Needs the
traceincrement and the estimated velocity!

--------------

**json** format
---------------

-  ``GEO_GEODYN2JSON``
-  ``3D_GEODYN2INFO``
-  ``3D_GEODYN2VTK``
-  ``3D_GEODYN2JSON``