| |
 
The module 2D data-analysis
allows the complete 2-dimensional processing of single shots,
zero offset lines or multi-shot gathers. The module is useful for the
following applications:
GPR (Ground penetrating radar)
reflection seismics
refraction seismics
borehole-borehole wave data
Import data
An import option allows the loading of the data for almost all
existing GPR and seismic data formats (e.g. GSSI, PULSEEKKO, RAMAC,
SEGY,SEG2). Single sections as well as a profile sequence (automatic
assembling and storing of the sections under one single datafile or
automatic generation of datafiles for parallel and inline-sections) may
be imported.
The data display
and printing possibilities
- display of the data either in wiggle (see right figure
above) or filled area point mode (see left figure above)
- "normal" reflection (time axis from top to bottom) or refraction
(time axis from bottom to top) display
- continuous display of the current mouse position parameters
including time, distance, amplitude and depth
- the user may switch between two different scale modes:
1. the data are completely plotted into the actual window with
subsequent free zooming and moving possibilities
2. trace based scale: the user chooses the pixel size for each
trace. If the line is not completely plotted into the window moving
possibilities are available.
- zoom- and autoscroll possibilities
- loading of a secondary profile, horizontal or vertical split-mode
or overlapping of the profiles
- interactive magnifying glass option (see left figure above)
with choosable zoom factor - a freely choosable data part is
continuously magnified when moving the mouse
- interactive color amplitude assignment for point mode -
display of the profiles in the point and wiggle mode
- many different plot options, e.g. rotated display,
combination of wiggle and point mode, free choosable axis and so on (see
central figure above)
- easy transfer of the data to the clipboard
- printing out the data with freely choosable scale either in
cm or scale like 1:1000; support of banner output (continuous printing
on printers which support banner output, e.g. HP Deskjet 1120 C).
- stack printing of a complete set of 2D-lines using the same
printing parameters
- oscilloscope-function - wiggle plot of the actual trace
with the indication of the actual amplitude, time and frequency
- comprehensive context sensitive online help
The dataprocessing
possibilities
A single radargram or seismogram section can be interactively
processed. Primary and secondary profile are displayed
simultaneously.
The batch mode allows the automatic processing for a choosable
number of lines. A sequence of processing steps will be applied on an
arbitrary number of profiles. The batch mode runs totally automatically.
Primary and secondary profile will be displayed, whereby a direct
control of the result is given.
All processing steps are stored for each profile and can be edited at
any time.
The dataprocessing is completely interactive. The effect of the
filter is online controlled when changing the filter parameters by
showing both the original and filtered trace. All edit inputs may be
entered either interactively in the original profile or using the table
input.
An overview of the different processing functions:
- Editing functions (like removing, extracting of single
traces/trace ranges, muting, stacking, subtracting or adding of
profiles and much more).
- Horizontal scaling of the data, automatically or manually
or by a combination of both.
- Flipping the profile in x-direction or y-direction.
- Static correction (interactive input of the correction
values, slant stack correction and so on).
- Gain-functions in horizontal und vertical direction, AGC (AutomaticGainControl),
automatic trace balancing, linear and exponential gain function,
automatic gain based on mean amplitude decay curve (see left figure
above)
- A great variety of 1D-filters like bandpass, notch-filter,
timedependent bandpass, crosscorrelation, arithmetic function,
averaging, median-filter, deconvolution, complex trace analysis (instantaneous
frequency, phase, envelope), time-depth conversion, background
removal, declipping and so on.
- Spectral analysis - single spectra, moving-window-analysis.
- Migration - 2D Kirchhoff, 2D fk-migration, 2D Finite
Difference migration with lateral varying velocities, 3D Kirchhoff.
- Some other 2D-filters like subtracting average, running
average, compress and expand and so on.
- F-k-filter with the possibility of manually input the
filter range within the fk- spectrum or by defining a velocity fan.
Different tapers and taper width are available (see right figure above).
- and much more possibilities
- All processing steps are stored in the header of each profile and
can be asked for at any time
batch-processing
The batch-processing (see figure) facilitates a completely automatic
sequence of processing steps for a choosable number of profiles.
Primary and secondary section are displayed simultaneously, whereby
a direct control of the result is given. You may choose between the
so called sequence mode and the single processing mode with the
possibility of applying the processing steps individually on the
primary profile. |
| |
velocity analysis
An interactive hyperbola-adaptation for a simple determination of
the average velocity from a zero-offset or CMP profile is integrated.
It is possible to adapt diffractions (see figure),
reflections and straight lines. You may change the
velocity, the radius of the target, the angle between the profile
line and the target and the width of the calculated diffraction or
reflection hyperbola.
There is also the possibility of fitting linear features either by
changing a line interactively or by setting two points. |
| |
|
The option core allows to vary interactively the velocities
of the single layers of the individual cores stored within an
ASCII-file.
In addition an interactive use of the intercept time method
for seismic refraction data is included (see figure). The option
enables to get a first 1D-model very quickly.
The velocities may be stored on file and may be reloaded at any
time. The velocities are combined into a 2D-model by using a
special interpolation. Such a 2D-velocity distribution may be used
in a subsequent step for the migration or the time-depth conversion. |
| |
|
Picking the onsets/first arrivals
The picking option allows to pick the traveltime and the amplitude
of different onsets like reflectors or hyperbola or the first
arrivals (see figure).
You have the choice between manual picking, continuous picking and a
semi-automatic picking using a phase follower (manual editing is
always possible).
The picked values may be corrected to the extrema or the
zero-crossing. In addition a time/distance correction to the maximum
value within a given window is available. This allows you for
example to pick the hyperbola cusps very quickly. |
| |
|
It is possible to export the picks into an ASCII-format together
with the 3 space coordinates for a subsequent interpretation. The so
called layer-show (see figure) offers the possibility to
combine individual pick files, to plot them together with the
wiggle-files and to output them in report form on printer or file
containing the depths, velocities and amplitudes of the individual
layers. The time-depth conversion of the picks is either based on a
constant velocity for each layer or on a 2-dimensional velocity
distribution allowing to take into account vertical and lateral
velocity changes. |
| |
|
|
