Newsletter - December2011
GPR-SLICE users,
I would like to welcome the followingorganizations to the GPR-SLICE community
· Central Florida Locators, Bushnell, Florida
· TUV Rheinland Service GmbH, Germany
· Ohio Valley Archaeology Inc, Columbus, Ohio
· School of Social Studies, University of Queensland, Australia
· Geophysical Engineering Dept, Istanbul University, Turkey
· Johannes Gutenberg University Mainz, Germany
· Advanced Infrastructure Design, New Jersey
· Utilities Division, Tower Surveys Ltd, Nottingham UK (www.towersurveys.co.uk)
· Dept of Physics, Astronomy and Geoscience, Valdosta State University, Georgia
· Foundation for Research and Technology Hellas, Rethynmo, Greece
· Constructions Solutions, Paola, Kansas (www.construction-solutions.com)
· Bryant Consultants, Carrollton, Texas (www.geoneering.com)
The University of Arkansas and GRadar Geofysik in Sweden have returned to the GPR-SLICE community after several years away. In addition, GPRSIM licenses were delivered to the Chickasaw Nation of Oklahoma and the Johannes Gutenberg University of Mainz, Germany.
USB Software Security Key Update ***Important***
Software security technology is changing and we need to change with it. New software security updates for the Marx USB keys is available. Since 2008, Marx Software has provided new technology for securing delivered software. We have finally been forced to make changes to accommodate their discontinuing the older MPI technology. Luckily, the conversion of your current USB key can be easily accommodated and we do not have to deliver new keys. On the GPR-SLICE Subscribers Only page website, please do the following:
1. Unzip all the files MPI2sx_v7.407, MPI2sx_v7.409, MPI2sx_v7.exe, fmteos.dll, gprslicev7.exe to the C:\slice\v7.0\ folder
2. Run MPI2sx_v7.exe to convert your USB to the Secured Applications Framework
3. Our new application to launch is still gprslicev7.exe
If the conversion is not made, gprslicev7.exe will not launch. Several users have already made the conversion and no problems with the new USB technology have been reported. The new technology will allow us to better control single and network licenses in the future as well as to deliver customized security solutions.
Software Updates
Among the more important improvements added to GPR-SLICE V7.0 Software over the last 3 months are:
· Resample in Range options added to GPS Track menu for total station or GPS fallout with survey wheel engaged
· Mala X3M, MalaCX11 and MalaCX12 formats and conversion for XY concrete surveys
· Grid HelpSet option for fine vs. draft grid cell size and broad vs. standard search radius
· Quick append of multiple information files in the Create Info File menu
· Maximum number of radargrams to process in 1 grid operation expanded from 5000 to 20000 radargrams (until more is requested)
· CALTRANS Standard for road layer evaluation delivered and in operation at the California Department of Transportation
· Background filtering options for line-by-line, grid-by-grid, or channel-by-channel added to the Filter menu.
· TSPoints pt/line options added to Open GL Volume Draw menu
· Solid 3D volume displays added to Open GL Volume menu
· Auto detection of the 0ns offset includes using settings for the threshold and N sample backup in the Slice/Resample menu
· Absolute elevation labeling added to Open GL and Radar 2D menus
Resample in Range option added to GPS Track menu for total station or GPS fallout with survey wheel engaged
Figure 1. Example of the resample in range operations in the GPS Track menu.
A special button to resample a GPS track or a total station track when fallout is presence was added. The Resample in Range button reads the track and then will mathematically integrate the length along the track to reset positions at the desired length. In the example in Figure 1 the total station track was resampled at 0.5. The requirement of the operation is that the data was also collected equidistantly along the ground (e.g. with a survey wheel). When fallout occurs with total station (or GPS) multiple points can be recorded in the previous locations until valid measurements are taken. The delete double GPS point option should first be engaged so that the general track movement can be mathematically integrated to give the most accurate resampling of the track that is synced with scans. This button became necessary for a recent dataset collected with a multi-channel equipment in a city street in Spain where buildings and obstructions caused the total station readings not to be properly updated.
Mala X3M, MalaCX11 and MalaCX12 formats and conversion for XY concrete surveys
Figure 2. Location of the import option for Mala X3M, CX11 and CX12 rd6 XY datasets. (Data courtesy of Shawn Williams, Idaho National Labs).
Mala X3M, CX11 and CX12 data integration is now available for concrete surveys. For either of these equipment from Mala GeoScience, the user will import the names of the *.rd6 multiplex datasets. On import, GPR-SLICE will create an infomain.dat and infoxy.dat files. Infomain.dat contains the names of the *.rd6 files and infoxy.dat will contain the names of the extracted *.rd3 files which will be made. The X end and Y end in the Create Info File menu should initially be set to the total number of files (less one) collected in each direction as shown in Figure 2. After import, the user then proceeds to insert the infomain.dat file into the Edit Info File menu and run the conversion to extract the individual radargrams from the multiplexed data. After this, the infoxy.dat file is inserted into the Edit Info File menu. If the profile interval was not 1 unit, then the user will multiply all the columns using the time x0,x1,y0,y1 button in the Edit Info File menu to quickly adjust the locations of the radargrams on the grid. After that, the XY decoupled gridding BlueBox Batch run can be started to automatically generate time slices and the 3D volume. An example of BlueBox Batch processing on a concrete structure is shown in Figure 2.
Grid HelpSet option for fine vs. draft grid cell sizes or broad vs standard search radius
Figure 3. Location of the new options to control cell size and search radius with the Help Set button.
An option to have some control on gridding using the Help Set button was added to the Grid menu (Figure 3). The cell size that was normally chosen on the Help Set button was programmed to generate "draft" quality grids on initial time slice generation. The user then could manually adjust the grid cell size to something finer should they like the draft grids. A new cell size "fine" radio button option was added that will set a grid cell size that is about 1/2 the size of the draft quality grid. The Help Set button was originally programmed to set the X and Y search radius to 1.5 the detected profile spacing. With the new "broader" radio button engaged, the Help Set button will set the detected search radius to 2.5 times the profile spacing. This can give much smoother looking grids (at the cost of some resolution). An example of a time slice map using the traditional draft cell size and standard search is compared with a time slice with fine cell size and broader search options engaged. BlueBox Batch operations will also read the settings in the Help Set to generate the desired quality and search lengths if the Grid HelpSet option is checked on.
Note, with finer cell size engaged the time slice maps will be 4 times as dense as well as take longer to process. In addition, with the broader search set the processing will also take longer. In the example shown in Figure 3, sometime smoother grids can be more beneficial than higher resolution grids that show less apparent connections to local anomalies.
Quick append of multiple information files - Create Info File menu
A listbox option to quickly append multiple information files together was added to the Create Info File (Figure 4). One user, Jeffrey Leon at Ithaca College had over 100 info files from separate grids that he needed to process entirely as a single dataset. The old method of typing in the names and the limit of appending only 2 information files at a time was tedious. One can now click on the info file list and continue adding in all the desired information files. The Append list will automatically write a character menu item as "info1.dat+info2.dat+info3.dat etc) which when the Append button is clicked will write the output information file (Figure 4).
Jeff was the first user to exceed 5000 radargrams in a single project. When GPR-SLICE for DOS was converted to Windows in 2001, I initially programmed the software to accept up to 5000 radargrams and had a message box to pop up if someone exceeded that number. Jeff had over 8000 lines. I have reprogrammed GPR-SLICE to currently accept up to 20000 radargrams. If anyone breaches this number of radargrams let me know and the array size will be increased to accommodate the expanding world of GPR surveys!
Figure 4. Option to append multiple information files by clicking on the desired number of files in the Create Info File menu.
CALTRANS Standard for road layer evaluation completed for the California Department of Transportation
Specialized options to report road layer thicknesses have been tested and further developed to meet the CALTRANS Standard set by the California Department of Transportation. The module contains all the necessary analytical operations for road layer horizon mapping and to report these results in the CALTRANS Standard file format. Most recently, a button to recompile the road layer results to a desired density on the ground was implemented to complete the CALTRANS Standard reporting (Figure 5). The functionality for recompiling horizon mapping results to a desired output density is also available for all GPR-SLICE licenses as well, in the Static menu (Figure 5 - bottom screen shot). A comma delimited file export-horzXYZN.dat where N is the horizon number will be written to the \dat\ folder of the project. The file will contain the detected horizon for all the radargrams in the project.
Figure 5. Example of the CALTRANS Standard menu and option for recompiling the density of the layer reporting. The same option is also available for non CALTRANS Standard licenses in the Static menu after running horizon detection operations.
Background filtering options for line-by-line, grid-by-grid, or channel-by-channel
Figure 6. New options in the Filter menu for background filtering line-by-line, grid-by-grid, or channel-by-channel are shown. Spectral phase and absolute amplitude conversion of radargrams is also provided near the Hilbert transform filter.
Several new options were added to the Filter menu at the request of users. Background filters can now be engaged as line-by-line, grid-by-grid, or for multi-channel users as channel-by-channel (Figure 6). The standard background filter provided in GPR-SLICE was line-by-line, where the average scan across the desired number of windowed scans was subtracted from the center of the filter. At large filter lengths greater than the total number of scans in the radargram could be used to remove the average scan across the entire radargram - e.g. applying a background filter. The danger in background removal is that linear features parallel to the profile can be inadvertently removed. A "safer" method to remove the background is to compute an average scan across the entire grid of data and then to subtract this remove each and every radargram. This can insure that a single linear target parallel to any given line will probably not be removed as this single profile would not over-weight the average scan. Putting the radio button option on grid-by-grid will compute the average scan over the entire grid before starting the filtering. Multi-channel users can also apply the new channel-by-channel option to compute the average reflection across a single channel in the entire grid and to subtract this average scan for background filtering.
A request to provide spectral phase and absolute amplitude of the radargram were added to the Hilbert transform filtering box in the Filter menu. The normal Hilbert transform will be engaged with the radio button set to magnitude.
TSPoints pt/line options added to Open GL Volume Draw menu
More options to provide 3D drawing and interpretation was added to the Open GL Volume Draw menu. A new line option can be used to connect drawn points (Figure 7). The points or any object can now be controlled by the mouse movement on any X, Y, or Z plane, as well as any X or Y radargram. The drawn object will only move along the chosen plane. When the mouse is clicked, the object will be stored in the desired location on the current active plane or radargram. The speed with which to draw and annotate volume has been enhanced with the new options. Before the arrow keys could only be used to move objects around. The drawn plane can be changed during drawing using the Step+/- buttons and the drawn objects will then get fixed to the new plane and stored there.
To end a line drawing, if the "line" button is clicked it will end close off the line; clicking the "line" button again will start a new line drawing. To shut off the last object drawn when that object is no longer desired to be placed into the volume, simply hitting that same object button again will remove that active object. Annotation to number the points is also available by clicking the annotate checkbox option in the menu.
Figure 7. Point-line drawing mode can be accessed in Open GL Volume by clicking the "line" button. The sphere button can also be clicked to store the points to any plane without line connections.
A new beta option to also show a solid Z volume plane is available in Open GL Volume (Figure 7). The option is still in the beta phase but is working well enough to give to users as another display option. With this new option, the original non-Open GL X,Y,Z volume menus initially ported over from GPR-SLICE for DOS have been removed from the software.
Auto detection of the 0ns includes custom settings for the threshold and N sample backup
For searching the 0ns offset, the threshold setting and the number of samples to backup from the detected threshold are now opened up in the Slice/Resample menu (Figure 8). The settings are similar to those in the Radargram Editing menu where unique offsets are automatically detected for each radargram separately. For many datasets however, the offset does not change and radargram editing operations are not necessary. Some radargrams have spurious noise as well as digital noises unrelated to recorded signals above the ground wave. The original default settings in the Slice/Resample menu had a threshold of .05 and a backup from the threshold detection of 4 samples. These options are now open for the user to customize for their particular radargrams. In the example in Figure 8 a threshold of .28 (28% of the peak response) is set and a backup of 3 samples after detection. A negative value for the N sample backup can also be set which would move the 0ns offset further down the scan after detection.