I Would Like to Welcome the Followingorganizations to the GPR-SLICE Community s1

Newsletter - November 2013

GPR-SLICE users,

I would like to welcome the following organizations to the GPR-SLICE community

 Dept of Anthropology, University of Northern Colorado  Nakano Technology Co., Ltd., Saitama, Japan  Dept of Classics, University of Cambridge  Dept of Civil Engineering and Geoinformation, Oldenburg University, Germany  Terraprobe, Burnaby BC, Canada (www.terraprobe.com)  Dudek and Associates, Encinitas, California (www.dudek.com)  Terrasond, Palmer, Alaska (www.terrasond.com)  Informatic and Information Security Research Center  Tubitak Bilgem, Turkey  TAG Research by Sturm Inc, New Mexico (www.tagrsi.com)  Buyeo National Research Institute of Cultural Heritage, Korea  Connected Water Initiative, University of New South Wales, Australia  Cultural Resource Consultants LLC, Anchorage, Alaska  Bronx Community College, CUNY, New York  Geonorm Project Engineering Consultancy, Turkey (www.geonorm.com.tr)  Tongva Ancestral Territorial Tribal Nation Consulting, California  Dept of Mining Engineering, McGill University, Canada

In addition, GPRSIM licenses were delivered to Dept of Earth Sciences, University of Toronto, Canada; Dept of Civil Engineering and Geoinformation, Oldenburg University, Germany; Guangxi Communications Investment Group Co., Ltd, China; Jiangsu Testing Center for Quality of Construction Engineering Co. China; Tubitak Bilgem, Turkey.

Software Updates Among the most important improvements added to GPR-SLICE V7.0 Software are:  Navigation markers inserted directly on the \radar\ folder  Slice/XYZ operation for working with native density radargrams  2d/3d Kirchoff Migration added to filter menus  Improved auto hyperbola detection options  0 median grid mosaic correction  User defined labeling - scan header labeling override for ANG surveys

Navigation markers inserted directly on the \radar\ folder

The title of this new option "Navigation markers inserted directly on the \radar\ folder" may seem strange but it has significant meaning for streamlining operations in GPR-SLICE. Historically, since the inception with GPR-SLICE for DOS, navigation was only placed on the radar scans after slice/resample operations were completed. The \resample\ folder radargrams contained navigation tags in the 2nd sample of the radar scan and only on these radargrams or radargrams processed from this folder, could navigation labeling be available. GPR-SLICE axis labeling requires navigation tags to exist on the radar scan in order to obtain a drawn label. GPR-SLICE operations now directly place the navigation tags on the scan headers in the \radar\ folder (Figure 1). The operation is only run one time on the \radar\ folder after which the Navigation menu never needs to run again. Previous GPR-SLICE applications required always returning to the navigation menu to apply navigation prior to running slicing operations on any processed folders. Also, had user tried to display \radar\ folder radargrams, no axis labeling would appear since navigation tags did

Figure 1. The new look in the Navigation menu where only the \radar\ folder initially has navigation applied only one time for all processes.

not exist on the \radar\ folder for survey wheel or GPS collections. Field marker radargrams would show axis labeling as the tags natively exist in the radargram scan header

Note: Previously, all operations for slicing would look at a file called the \marker\*.mrk files which were generated when running the navigation. These files contained the list of scan numbers in the radargram where xy navigation is known. These files most did not know existed as they were in a separate folder inside all projects and never directly accessed. The \marker\*.mrk files are now not used although still being written. The marker tags directly stored in the radargrams are read internally wherever operations requiring the scan numbers are needed, such as in slicing operations or xypoints etc.

Note: For users that navigate a survey with field markers and do not use survey wheels or GPS, only the Field Markers operational button should be clicked in the Navigation menu. Clicking the Artificial Marker operation for instance will erase the field markers in the converted radargrams. If this or any other navigational options such as Interval Markers or GPS navigation buttons are accidentally clicked, the user will need to reconvert the radargrams from the Convert menu in order to see the original field markers.

The idea to place navigation tags directly onto the radar scans in the \radar\ folder initially - rather than requiring resampling operations where marker tags are assigned, came about as several users asked about using the native radargrams without having to resample the radargrams, especially for data collected with a survey wheel for instance. By placing the tags into the \radar\ folder radargrams, working with the native scan density collected on a site from a survey wheel is now available. This discussion takes us to the next major operational option now in the GPR- SLICE software:

Slice/XYZ operation for working with native density radargrams

Figure 2. Slice/XYZ operations were no resampled radargrams are generated are now available for working with only the native density radargrams.

With the application of placing navigation tags into the \radar\ folder radargrams, the necessity to resample radargrams is no longer a requirement. Users can now simply run the Slice/XYZ operation and never need to generate the \resample\ radargrams if so desired (Figure 2). For those that are concerned about using only the native radargrams then this button may be the operation of choice. Resampled radargrams of course have advantages such as a constant number of desired scans between recorded navigation tags which can make 2D displays often more visually desirable. In any event, if a user chooses a proper resample/scan value then resampled radargrams will always have the same resolution in the native - recorded radargram.

Restating these two latest options added to GPR-SLICE for streamlined operations are:

 markers tags are now stored directly in the scan headers in the \radar\ folder

 navigation only needs to be run one time initially on the \radar\ folder

 processed folders from the Filter menu do NOT need to have navigation reapplied

 native scan density \radar\ folders from can now be used for all processes

 \resample\ folders will continue to be made and can also still be used for all processes

Note: BlueBox Batch operations currently still contain resampling operations. We may see about providing options for working with native scan density radargrams in the future for BlueBox operations.

Improved auto-hyperbola search function

A new algorithm to automatically detect hyperbola on radargrams has been advanced (Figure 3). The new Autosearch2 button will engage a 5 point search. The search will look along a horizontal line from the mouse location which is typically placed near the apex of the hyperbola. Normally you will want to place the 5pt search line on the 2nd pulse of the return and center it. If you do this and properly adjust the migrator width, the software will set amplitude thresholds automatically on the center, points 1/4 and points 1/2 the total migrator width on each side. If you choose a proper migrator width, the outside points (#4 and #5) will have the opposite signs then the inner 3 points. Searching the hyperbola with this algorithm

Figure 3. Location of the new automatic hyperbola detection operation for examing 5 pts across the hyperbola apex. has proven to work significantly better than the scan/threshold method which is still in the menu. The operations are to click the Help 5pt button, move the hyperbola/line to the desired location, then left click the mouse. This will update the search parameters dx1-5 which are the nearby scan locations from the center, dy1-5 are the horizontal samples on the pulse, and a1-5 are the amplitudes at the 5 points. The amplitudes a1-5 are decreased from the actually amplitudes at those locations. The point a1 is stored as .8 of the detected value, a2-3 are recorded as .5 and a4-5 are recorded as .25 the actual recorded values to insure that amplitudes of slightly weaker hyperbola can be detected. These slots can be manually adjusted as well. The dy1-5 slots are always shown as 0 for the help 5pt search. However, these can also be adjusted by the user for a more customized search. For instance, searching a Hilbert transform-migrated radargram, one might one to have a vertical search on the pulse to isolate a strong anomaly etc.

Note: Autosearch2 still requires one to set the N-Skip and the N-Nearby settings. The N-Nearby setting will automatically look N scan to the left and right, and N samples up and down from the first detection location to find the peak response from the initial detection. The N-Nearby functionality is also engaged should the user want to manually insert hyperbolas into the detection window. A value of 0 on the N-Nearby would yield exactly the detected location; values of 2-4 can assist in making the detected hyperbola more centered on the feature. There is also new setting call S-Backup. S- Backup will move the drawn hyperbola N samples on the pulse. S-backup is used to predict the first arrival of the wave and not the peak response, to give a better estimate of the depth to the top of the rebar. Even though the S-backup is engaged, the value of the peak response is reported and not the value where the hyperbola is drawn if this options is set to other than 0.

Kirchoff migration

Figure 4. Kirchoff migration operation in the 2D Filter menu.

The first migration routine provided in GPR-SLICE was diffraction stacking of the recorded hyperbolic reflections (sometimes referred to as simple hyperbolic summation). An improved migration routine - Kirchoff migration - that works similar to hyperbolic summation but accounts for amplitude adjustments for spherical spreading of the radar wave and also the obliquity of the wave on its arrival to the ground surface is now available in the Filter menu for 2D and 3D processing. (Figure 4) The Kirchoff migration is the recommended migration routine and it performs better than simple diffraction stack migration. This routine also does not have any edge effects at the bottom of the radargrams as spherical spreading adjustments will properly weight the diffraction stacking of amplitudes in the migrated pulse (as seen in the example in Figure 4) .

0 Median grid mosaic correction

Figure 5. 0 Median grid and 0 mean grid operations buttons are now available in the Mosaic Correction menu.

A new algorithm to try and automatically correct mosaic correction has been added to the stand-alone Mosaic Correction menu (Figure 5). The operation works by calculating the median value of each defined grid division (defined in the info menu) and then normalizing all the blocks by their median value. For certain kinds of surveys noises the median grid algorithm may work to balance the different survey blocks. This method is best suited to surveys where the distribution of data are similar in each of the blocks. e.g. the same number of weak, medium and strong anomaly areas are about the same density in each of the blocks. 0 mean grid operations are also now provided in the stand-alone Mosaic Correction menu. To properly view the 0 median corrected grids the user should run the operation on grid #1 so that this grid set will appear in the Pixel Map for further viewing an display.

The Regrid option can also work very effectively in the menu to adjust mosaic noises real time. In this operation, the user sets the desired block with the div+/- button, adjusts the gain or the dc offset to balance the data with a nearby block, then uses the Regrid button to re-grid the *.dat using the adjustments. In this method, while applying the gain or dc adjustments to the actual grid, edge effects will be seen in the drawing along the block edges. This is to be expected since the gridded data at the edges were generated with unmatched searched data from both nearby blocks. However, on re-gridding, the original *.dat is used to recalculate the grids and those edge effects will not be present after the operation. For 0 median and 0 mean grids, new *.dat and *.grd data are generated with the "0m" appended identifier. For the Regrid option, the *.grd is overwritten with the original name. For 0 median and 0 mean operations and the Regrid option, the original *.dat must exist for the corresponding displayed grid file. Direct gaining on the *.grd file real time with writing to the "m*.grd" file is available and does not require *.dat data to exist.

User defined labeling - scan header labeling override for ANG surveys

GPR-SLICE has traditionally only outputted labeling on 2D radargrams that comes from the scan headers where navigation tags are stored in the 2nd sample of the digitized pulse. This has been a double check on navigation - as only tagged scans can force a label in the radargram displays. Even if a radargram is defined as some length in the info.dat file and there are no navigtaion tags in the radargram scan header that were applied through the Navigation Menu, no labels will appear on displays. For ANG surveys, where there can be fractional line lengths, the navigation tags may not be at integral lengths in the radargrams. Navigation tags for ANG surveys can be at non-integral lengths. The reason for this is in the process of creating time slices and a need to properly include and equal weight all portions of the radargram in the time slice binning process, tags are set at non-integral locations. For instance a 10.0 meter radargram, would get tagged with 11 navigation tags but a 10.43 metter radargram for would get 12 navigation tags (including the scan #1). The user would be able to break down the 12 tags in the radargram with the Cut Per Mark option to generate additionally smaller bins for time slice operations. With that said, because of the non-integral location that can occur with ANG survey for the tagged scans, on displays, the labeling will show at fractional numbers. This also requires that the # of decimals in the x axis display be set to something other than 0. Several users complained that they could not get out equidistantly labels at a desired graphic increment. For this reason, an old option that was taken out of the software has been re-instated (Figure 6). The Big Tick frequency, if set to a negative value in the Options menu, will override the scan header navigation Figure 6. Location of a flag for overriding scan header tags and customizing labeling to any interval desired (normally for ANG defined surveys).

- and provide a completely graphical labeling where the user can control the interval between labels.

An example of a traditional scan header labeling for an ANG survey line that is 10.43 m and what can be achieved with a negative Big Tick frequency option is shown in the following figure. In the traditional ANG survey, the labels have fractions in them. With the override engaged the user can achieve any integral display on the tick labeling. The tick labeling interval can also be sub-integral if desired by clicking off the Automarker labeling checkbox in the Options menu.

Note: Scan marker override option is only available for X, Y, XY or ANG surveys and is not applicable or available for GPS surveys.

Other features and options added to GPR-SLICE include:

 Tiff image export and world file TFW extensions added to the Pixel Map menu

 Double precision of writing dxf object file in OpenGL Volume with UTM or large coordinate offsets

 Lat/long and lat/long decimal range display options available in the OpenGl, Radar 2d menu and the Pixel Map menu

 Front and back label reverse location display in OpenGL

 OpenGL 2+ labeling places front depth label in back of volume

 GPS log filename extensions setting option available in Create New Info menu to allow for various custom logging conventions

 Import XYZ point file into OpenGL Draw

 Active projects dimension increased from 500 to 5000

 Warning message box on double GPS points and Double GPS scan#s on GPS log file conversion in the Edit Info FIle menu along with recommended filtering in the GPS Track menu

 +/- time slice scroll buttons added to Multichannel menu for large areas and in the regular 2D Pixel Map menu

 Append option added to TSpoints

 TSpoints in the 2D Pixel Map menu importable in OpenGL Volume Draw menu

 Import Geodata, xzyd format added  Grid division between two time slice datasets added to Grid menu

 DXF negative z elevation and undo/redo buttons added to OpenGL

 Auto deletion of decrementing scan numbers in GPS log files

 FK radargram filtering - beta version working for small files with scans less than about 2000

 Append identifier to rename a set of truncated radargrams added to the Radar Edit menu - useful for separating Dual Frequency radargrams written double long

In addition, many minor and several important bug fixes were made and all users should download the latest software.

Note: All users will need to update their current version of GPR- SLICE to insure their software will launch after January 1, 2014.

Supplemental manuals and/or Powerpoints discussing in more detail operations in GPR-SLICE are now available on the Subscribers Only page of the website. Two supplemental manuals are currently downloadable and discuss:

 Vector Radial Tunnel Operations in GPR-SLICE  Importing and Displaying EM data in GPR-SLICE

On the multi-channel page of the website a new supplemental is available:

 GSSI SIR 30 Operations in GPR-SLICE

Recent and Upcoming Events

GPR-SLICE workshop class from Sept 28-29 was taught by Dr. Alex Novo in Montreal and was attended by 10 people from coming from Brazil, Canada and the US. Alex has scheduled be a 2 day GPR-SLICE workshop in Pontevedra Spain the University of Vigo from December 18-19, 2013. Details on this workshop are available on the Upcoming Events page of the website and our facebook page. The dates for 2 day workshop in February in Woodland Hills California will be scheduled shortly.

20th Anniversary of the Nutubaru Kofun Survey

For those that are not familiar with the origin of the GPR-SLICE logo, it came from a survey Koji Tobita and I did back in 1993 with Yasushi Nishimura from Nara National Cultural Properties Research Institute, and with Hiromichi Hongo and Noriaki Higashi from Miyazaki Prefecture Dept of Archaeology in a field in Shintomimachi on the island of Kyushu in Japan. In these days we were still working with analog equipment and 16 mb tape drives and 50 m antenna cables in the field! It was not so streamline to collect data as we required gas field generators required to power the equipment as well as experiencing recording issues and missed data records on magnetic tape. The yellow plastic tape on the control unit was to insure that the analog gain controls did not inadvertently get changed which could mess your day up. A 2 day filed survey on November 12 and 13 was batch processed on the evening on the 13th and into the early next morning. We woke up to see an unexpected perfectly round anomaly, 22m across from a 6th century destroyed - Kofun period burial mound. The strong feature inside the round moat is a collapsed burial chamber. The results were published in the Miyazaki Shimbun on November 14. Up to this point in our limited GPR experiences our lab had yet to see such a beautiful image which clearly indicated that we could discover a lost structure that our ancient ancestors had built.

The 20th anniversary of the image taken on the Nutubaru Burial Mound is this month. Time flies! cheers...Dean

Dean Goodman Geophysicist, Phd GPR-SLICE Software Geophysical Archaeometry Laboratory Inc. [email protected] [email protected] www.GPR-SURVEY.com facebook: https://facebook.com/pages/GPR-Slice/124352290972979?ref=hl

*This newsletters is available in *.doc form on the Subscribers Only page of the website