Key Words:
Horizon
OpenGL 2D
Newsletter – October 2007
GPR-SLICE and GPRSIM users,
I would like to welcome the following organizations to the GPR-SLICE community:
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Buyeo Cultural Heritage Center, Korea
School of Conservation Sciences, Bournemouth Univesity, UK
Ministry of Defense, Israel
Landscape and Geophysical Services, Ireland
GeoHiRes International Ltd., Germany
Dr. Mi-Hyun Lee who works for the BUYEO Cultural Heritage Center in Korea signed on to the GPRSLICE and GPR-SLICE VIEW softwares after seeing very positive results of GPR surveying and
GPR-SLICE imaging. GPR-SLICE has been extensively used by Dr. Hyun dok Oh at the National
Cultural Properties Research Institute. His work has gained much attention and he has
influenced several new users recently in Korea.
Dr. Paul Cheetham and Dr. Jeff Chartrand at Bournemouth University have been following GPRSLICE developments for many years and they finally received funds to acquire the software. After our
initial training session Paul and Jeff were very positive about the software. Paul believes that GPRSLICE should be used more extensively in their forensic archaeological researches and by the
community at large.
The Ministry of Defense in Israel acquired GPR-SLICE through a reseller. Unfortunately I can not
introduce anyone directly that is using the software. The reseller was Yoge Shimony of Software
Sources Ltd, in Ra'anana, Israel.
Dr. Kevin Barton of Landscape and Geophysical Services in Ireland spent several months evaluating
the softwares before signing on. Kevin’s company is our second organization to begin using the
softwares in Ireland.
Dr. Andreas Kathage and currently with GeoHIres International Ltd in Germany www.geohires.com
requested a subscription to GPR-SLICE. I have known Andy for almost 18 years. I actually met him
the first time I ever went to GSSI to pick up our first equipment back in 1989 for our Japanese
laboratory. Andy is very well known consultant in the GPR world and is a very well respected antenna
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designer as well. He was actually introduced to GPR-SLICE back in 1994 when he purchased the
DOS version of GPR-SLICE. He has had an opportunity to see the improvements in the software since
the mid-90s. Having Andy on board is another very positive event and a validation of our software
solution .
The number of GPRSIM v3.0 users has also recently got some interest. We just signed the 25th user to
this software solution for simulating GPR. The following organizations signed onto GPRSIM in the
last month include:
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Zetica, England
Samsung Engineering and Construction, Korea
University of Vigo
Asger Erikson from Zetica was a user of GPRSIM for DOS and wanted to update his software to the
Windows version.
Dr. Hyoung-Seok Kwon who is part of the Institute of Construction Technology at Samsung
Engineering & Construction in Korea discovered GPRSIM v3.0 on the internet.
Alex Novo and Henrique Lorenzo of the University of Vigo are GPR-SLICE users and they also
wanted to expand their researches into GPR using our simulator. Their primary research will be to do
forward modeling on Roman bridges to determine reconstruction and remodeling phases in these
structures.
We welcome all the new users to the GPR-SLICE and GPRSIM community!
Update:
Several new options were added to GPR-SLICE over the last 2 months:
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Automatic horizon detection in the Static/Horizon menu
2D OpenGL surface plotting menu
GPS fallout error threshold added to GPS track menu item list
GPS radargram tags added to \radar\ folder for display
1. Automatic horizon detection in the Static/Horizon menu
A new option to automatically detect and map subsurface horizons has been implemented in the Static
Menu. The Horizon submenu can now automatically discover the peak reflection within a user
specified scan-sample window. Shown in Figure 1 is an example of the operation of the menu. The
sample start/end are the range for discovering the peak reflection. Running the Auto Detect will
discover and display the peak response. There is an auto filter switch which is available in the menu.
The auto filter switch will compare a moving average with the discreet profile to try and remove noisy
points real time along the profile. In the case when the filtered profile still has problems, the user can
click the Import/Edit Horizon button and fix the profiles with the mouse very quickly. A 3-scan
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mouse cursor is used to help quickly re-draw bad points along the profile that are not well predicted.
The thickness of the drawn profile can be adjusted in the Options menu using the pen width located
in the contour menu item list. The automatic horizon detection can be run in batch as well using the
Auto Detect Batch button.
Note: There are options in the Static menu to compile all the horizons to a file - horizon1.dat, grid it,
smooth it, and then to do the horizon corrections using a gridded and smoothed horizon surface.
Making the horizon correction followed by time slicing the horizon corrected radargrams, essentially
give one horizon slices as opposed to our normal 2d "flat" time slices.
This menu will eventually be expanded in the future to include multiple horizons. We hope to provide
a display for multiple detected horizons using 3D Open GL where the stratigraphic structures will be
mapped and easily accessible.
2. OpenGL 2D surface plotting menu
A new menu to draw 2D surface maps is now available for authorized OpenGL licenses. In the menu,
there are Z scaling buttons to reduce or increase the surface anomalies. Clicking the Z scl- button
twice will make 2D flat displays which can be rotated and tilted real time. The time slices can be
incremented by clicking the + and - buttons. Before using the 2D OpenGL menu the user should set
the number of time slices and transforms in the Pixel Map menu. The OpenGL 2D routine reads these
menu items as its initial input.
Several users helped to evaluate this new option over the course of a month. Among the
additional requests was to provide jpg outputs as well as to automate the animation creation. There is a
Store jpg button which will create one jpg with current identifier being the time slice file name. To
generate an animation, the user can click the Generate Animation button. This will cause the
OpenGL 2D routine to display all the time slices set in the Pixel Map menu and create an animation. I
have placed an example animation at www.gpr-survey.com/practice for OpenGL users and nonusers to see this new functionality and display in this menu. At this ftp location download the
OpenGL-2D-Animation.zip file to see this demo. This is the standard animation menu folder that
users can make using the export button in the Animation List menu. Locate the GPRSLICEAnimations.exe file in the folder to run the animation. The site data was provided by Kent Schneider
and the Seminole tribe of Florida and is a Seminole cemetery located in Florida. Several rows of
burials can be seen to appear at various levels within the complete 3D dataset.
Notes: Currently to generate an animation, the OpenGL 2D window should remain maximized.
Creating JPEG outputs in OpenGL are a slightly different than the rest of the code and I am still
learning all the details in this very powerful graphic library. This OpenGL option is part of the main
GPR-SLICE exe file and is not a separate application like GPR-SLICE VIEW.
3. GPS fallout error threshold added to GPS track menu item list
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An error threshold was added to the GPS Track menu to automatically remove GPS fallout that is
some user defined percentage away from the average UTM readings. This setting in the Track menu
should not be used to try and remove points that are only a meter or so away from its estimated
position. The setting is for fallout where the recorded readings are from corrupted navigation numbers
that are incorrectly recorded or from loss of satellites. In these instances, the GPS fallout are number
far away from the average UTM numbers.
4. GPS radargram tags added to \radar\ folder for display
Normally in GPR-SLICE navigation tags or range labelling along the radargram will not appear for
displays of radargrams in the \radar\ folder. The only time that you could get labels to show in the
\radar\ folder is if the lines were recorded with user markers and not from a survey wheel survey. The
navigation tags and the labels will always appear in the \resample\ folder or filter folders that used the
\resample\ folder, and it will be there for all surveys performed. For those that did not know, resample
data or other folders can be navigation using the Field Marker option in addition to the Artificial
Marker option since tags are placed in to the radargram. Recently however, a necessity had come up
for navigation tags to be available in the \radar\ folder for GPS recorded surveys. To implement this
into the radargram displays seems trivial but was very difficult to accomplish. Nonetheless, we have
accommodated a request from GPR/GPS users to allow the navigation to be displayed for GPS
navigation surveys and for this navigation to appear in the \radar\ folder for these radargram displays.
Bug Fixes:
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Graphic memory leak in the Pixel Map and 2D Radargram menu
Topography adjusted 3D volume file
3rd tier dialog causing minimizing of GPR-SLICE to the Windows task bar
Several "good" bugs were discovered and fixed. A graphic memory leak was a problem since GPRSLICE became v5.0 in 2005. Often plotting more than 10 or 12 time slice windows consecutively or
radargrams windows could cause subsequent graphic screens to go gray. The only option to fix this
was to exit the software and go back and redisplay the window. This bug was reported by several
people over the years and most recently Martine Roseveare. I never officially mentioned it in any
newsletters since I was a touch embarrassed by it. I could not discover the cause of this bug until just
recently. It is very nice to have found and corrected this problem.
Another bug was reported by Erich Fisher of University of Florida. There is an option in GPR-SLICE
to adjust a 3D volume file and to generate another 3D topography adjusted file which can be imported
to any menu. The z axis of the converted topography file was inverted. This bug existed for almost a
year in the software and has now been fixed. I had only used the option several times in the last year
and unfortunately the datasets I had were not conducive to illuminating this problem.
Another long term bug that seems to have been more prevalent in Vista operating systems, but was
also present in XP, was the minimizing of GPR-SLICE on the task bar if a 3rd child dialog was opened
up. This minimizing would only happen if another application was running on the desktop and that
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application was not minimized. With the new fix, GPR-SLICE will keep focus on the desktop unless
the user decides they want to minimize any menus.
I thank Martin and Erich for reporting the problems that we were able to fix. The new options to GPRSLICE and the fixes have been loaded to the Subscribers Only page of the www.GPR-SURVEY.com
website, password "Gypsy Ln".
Operational Notes:
More and more Mala users seem to be coming onboard to the software. We have examined several
datasets and others have reported similar problems. Striping noises in Mala datasets appear to be more
prevalent in recent surveys we have looked at. The results were recently verified independently using
a software package at the University of Miami and also from Mala's own software. We referred to
these noises in the past as "shielding" line noises as we believed that the unshielded antenna may have
different responses to external sources, causing a zig-zag survey to conspicuously show varying
responses every other line. We suggested last year in a newsletter that the best way to alleviate these
noises is to process forward and reverse lines separately and then use Grid Math options in the Grid
menu to add the separated forward and reverse time slices. This method is still working very well and
we refer the Mala users to use this method to effectively remove the striping noises.
In recent side-by-side researches with Alex Novo from the University of Vigo, Billy Silva from the
California Dept of Transportation, and Paul Cheetham and Jeff Chartrand at Bournemouth University,
we processed several datasets using the method of separating forward and reverse lines. An example
of the striping noise and the removal by grid math is shown in Figure 3. I have many more examples
as well from our recent GPR workshop on Santa Cruz Island where we employed Mala equipment to
survey Chumash Indian sites.
Alex believes that the noise may not be shielding noise but may be related to small changes in the tilt
of the antenna between forward and reverse lines that cause the problem. The reason he believes this
is that they ran tests where the antenna on a zig-zag survey was not rotated. The cart was simply
pushed backwards on the reverse line. They believe that the cart system employed for the survey may
have tilted differentially between forward and reverse lines when working in the field. Whatever the
cause of the problem GPR-SLICE has a solution for removing striping noises from a zig-zag survey.
Upcoming Events:
GPR-SLICE/GPRSIM will be exhibited at the upcoming Geological Society of America meeting at
the Denver Convention Center between Oct 28-31 in both 502. For more information or to request
exhibit passing please contact us. http://www.geosociety.org/meetings/2007/
The annual GPR-SLICE workshop at the USFS Kisatchi National Forest in Alexandria, Louisiana will
be held from Nov 12-15. Details on registering can be found at
http://www.gpr-survey.com/gprslice/upcomingevents.html.
This newsletter is available on the Subscribers Only page of the website in an MS Word document.
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best wishes, Dean
Figure 1: Auto horizon detection in the Static/Horizon correction menu (data courtesy of Daniela
Hofmann, Weibe Group).
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Figure 2: Open GL 2D surface menu added to the software for authorized licenses (data courtesy Kent
Schneider and the Seminole tribe, Florida).
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Figure 3. Example of raw and processed time slices from Mala equipment (data courtesy Paul
Cheetham and Jeff Chartrand, Bournemouth University).
___________________
Dean Goodman
Geophysicist, Phd
Geophysical Archaeometry Laboratory
20014 Gypsy Ln
Woodland Hills, CA 91364
www.GPR-SURVEY.com
dean@gpr-survey.com
gal_usa_goodman@msn.com
818-716-6957
818-434-9932 cell
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