Newsletter – March 27, 2006

GPR-SLICE Users,

I would like to welcome two new users, Jakub Stainbruch from INSET s.r.o. in the Czech Republic (www.inset.com), and Mark Yates who works for a governmental agency in the United Kingdom. There are now 61organizations using GPR-SLICE Software with some of these organizations having multiple licenses.

I would also like to introduce Dr. Mario Forestaof IGS Idrogeostudifrom Catania, Italy http://www.idrogeostudi.com/. Mario is our first distributor of GPR-SLICE in Europe. Mario will beattending the SAGEEP conference in Seattle next week and he will alsobe helping at our booth as well as getting some additional training on GPR-SLICE. I have received inquiries from 3 other commercial companies recentlyfrom Australia, the United Kingdom, and Polandregarding representation ofthe software. There will probably be a few more announcements regarding these developments in a future newsletter. The one thing about having some distributors for the software is that they will also be involved in training and technical support to local users which will be necessary as we are starting to grow at a more steady rate now. Within about 9 monthsI hope to begin providing language support for GPR-SLICE in Japanese, Italian, Spanish and any other languages as they are requested.

There aremany new features which have been put into the code over the last4 weeks and that we will now detail to you.Most ofthese features were put into the software at the request of users:

1.  Ts-points real time dialog editing

2.  GPS points overlay for custom grid blanking

3.  Non-point source hyperbola fitting

4.  Conversion of GSSI 8 bit radargrams for wobble and header removal

5.  Formalized import option for processing any 2D geophysical data, such as mag, resistivity, etc.

1) David Taylor at Spectrum Geophysics requested a feature that a dialog appear when one runsthe TS Pointsoption to collect mouse clicks over time slice anomalies. Before, the TS Points option (launched by right clicking the mouseover a time slice graphic), would simplywrite a file in the background. The newdialogthat pops up nowallows the user to be able to edit input to the file real time. An example of the TS Points option and the new dialog with editing capability is shown inFigure 1. Right clicking with the time slice/radagram split will also launch the TS Point dialog. We will hopefully have a similar option available for choosing anomalies directly on the radargrams as well.

2) Brian Haley at the University of Mississippi requested that GPS points be overlaid when one wants to blank out areas in GPR-GPS time slice maps. Brian has been working at cemeteries using only GPS navigation. When interpolation is being done, areas will be interpolated into areas that do not have any data up to the search radius. Some areas where there are very thin GPS locations or errant locations the user may want to remove these areas from the time slice maps.Correlating the GPSlocations will allow the user to create a customized blanking grid to run in batch which will preserve additionalareas the user wantsleave blankin the time slice maps. Shown in Figure 2a is on time slice map made with a small gridding search radius so the user can actually see the radar track. The GPS points are overlaid on the time slice track. The user can then user the blanking option to remove the areas on the track which they want to leave blank in the time slice map. Shown in Figure 2b is the same GPS time slice made with a larger blanking radius to fill in/interpolate the spaces between the GPS track map better.

3) Another option that was put into the software is measuring the hyperbolas from non-pt source targets. Shown in Figure 3a is the shape of hyperbolas from circular objects having various radius. The larger the radius an object is, the slightly broader the apparent hyperbola recordedis. The formula for the shape of theTvsX curve for a non-pt source hyperbola is also shown. The option to detect the velocity of a material if the radius of a pipe is known, can now give more accurate estimations using the Hyperbola Search option in the Filter menu (Figure 3b). I developed this softwareto assistrequests by some investigators working with NASA in Italy that were trying to locate meteors beneath the landscape. If one knows the microwave velocity very accurately at a site, then you can adjust the radius, rather than the velocity, to get a best match to the recordedhyperbolic reflection.

4) All data, including GSSI 8 bit radargrams must now be converted in the Convert Data menu. Before, we use to allow GSSI radargrams that were 8 bit to forego data conversion. Not anymore. All GSSI 8 bit radargrams must also be converted. The conversion process now will remove the 1024 byte header from the converted radargram. 8 bit GSSI radargrams must now be put into the \raw folder and then converted. The conversion also has the option for including gain as well as removing the wobble/dc-drift in thedata. I decided to do this because we noticed that the 1024 header was becoming a “nuisance” in making a standard package for filtering and processing. Once Convert Data is implemented all radargrams whether GSSI, SS, MALA, Penetradar or any other manufacturer, are all treated identical and are in a standard GPR-SLICE dataformat. You must now use the process GSSI 8 to 8 bit button in the Convert Data menu to insure that the 1024 GSSI header is cut off before all further processing (Figure 4). Again, once the Convert Data menu is implemented, all radargrams from all manufacturers are put into GPR-SLICE format. Figure 4 also shows that 8 bit GSSI radargrams can also suffer the same noises that Sensors Software(and Mala)have where the wobble/dc drift is very pronounced. Using the Gain-Wobble data conversion will now give GSSI 8 bit users cleaner radargrams and less noisy datasets for time slice operations.

5)Over the last months severalusers again have askedabout using GPR-SLICE for importing and processing other geophysical data. We have now officially formalized importing of non-GPR data into GPR-SLICE. Show in Figure 5a is the new pull down option in the Grid Menu call “Import Geophysical Data”. The data to import must:

a)  reside in the main project folder with the extension *.dat

b) must have no header line

c) be a file that is comma delimited and simply written as x,y,data

Clicking the Import button will make a new file which will place the letter “1” before *.dat, e.g mydata1.dat. To grid this data you then simply go to the gridding menu and do typical 2D gridding. An example of a magnetometer dataset processed in GPR-SLICE is shown in Figure 5b. For imported geophysical data, the absolute values of the data are preserved. In radar of course the absolute values of data are not as important and thus we do not normally show the values of the data in the grid maps. However, for imported data, such as magnetics or resistivity or even susceptibility, the absolute units are important. For this reason, when one clicks the Color Table/Transform to “on” in the Option Menu, the color table will be drawn with the minimum and maximum scale of the imported data.

If one has data from various instruments at the same site, it is possible to use the Overlay Analysis options in the Pixel Map menu to create composite maps from various geophysical methods. The Overlay Analysis, which is a process unique to GPR-SLICE,will create a composite as a binary process where only the relative strongest reflectors (e.g. transform colors) will be preserved in a composite overlay map. If any users have multiple datasets from a single site which allhave the same grid size, I would be interested in assisting you in making anOverlay Map as well as to have a dataset to provide additional options such as RGBcolor compositing, etc.

These are the brief details of the latest updates. These new options are availableon the Subscribers Only page. Please note, you will need to runCBSETUP.exe again tore-install yourparallel port or USB security driver. Marx SoftwareSecurity (www.marx.com)has a new firmware update and you will need to get the latest driver installed. The password to unzip the update is “Gypsy Ln”.

As you can see again, therehavebeenmore extensivedevelopments which all active subscribers have access to. I am hoping to reduce the number of developmentsover the next 2-4 months. Therehave been more requests for developments, many of which areextremely customized, however, they will be useful fornewautomated applicationswith GPR-SLICE. Brian Herridge and Erik Kittat 3D Geophysics requested an automated hyperboladetectionmodule to discover rebar in concrete and to give their depth, location, and some kind of confidence in the fit of the hyperbola for infrastructure and road evaluations applications. I also have requests to redevelop the Pixel Map menu to make convenient buttons above the time slice graphic and in the same dialog. There have been other requests for filtering of differential GPS navigation data which we also hope to be able to provide a reasonable solution for in future updates.

GPR SLICE Operation Notes:

1) For those making*.gps files from Excel youneed to export theGPS files with MS Text format. There is a carriage return that will not be read properly on the last line if not exported this way. This situation is actually a Power Basic for Windows compilerissuewhich I contacted Power Basic aboutand theytold me they will resolve in thisnext update coming out within a month orso. Until they do use MS text Format.

2) Several users have contacted me regarding putting in fractional line lengths. GPR-SLICE can handle any navigation and you are not required to work only in meters or feet and have these as your integral line measurement. A fewusers have been working in meters and put the line lengths in fractional meters. This is incorrect. If you want to work in fractional units in meters you need to set line lengths in centimeters. If you can round to the nearest 10 centimeters for instance, then your unit per distance when you create the info.dat file should be 10. Then your line lengths must be written in centimeters rounded to the nearest 10 centimeter interval, e.g. 720 or 550 etc. You can not write 722cm for example. The reason being most users do not have at least 1 scan or more per centimeter. If you try to binning which is the key to our imaging solution, you may have some bins with no data. If you work in centimeter intervalsand have at least a few scans per unit distance of 10 cm than set the unit/marker to 10.If you believe you need centimeter accuracy, then you must record atleast 1 scan or moreper centimeter to get this accuracy inimaging. Forsmall scale rebar surveys you will need to make sure you are recording thisdensity. I have included anexample of the info.dat file for a survey recorded in (10)centimeter accuracy for your reference in Figure 6.

Upcoming Events:

GPR-SLICE will be exhibited at several professional conferences, including the SAGEEP in Seattle (April 2-6), the Society of American Archaeology in Puerto Rico (April 26-29), and GPR 2006 (June 19-23)where we will have GPR-SLICE/GPRSIM booths. All users are invited to attend these events andwe hope to arrange a get together dinner at each location. Also, I will reserve the evenings for instruction on the software at these meetings for those users that are attending.

Steve DeVore’s annualRemote Sensing workshop thisyear will be at Ft. Frederica, Georgia, from May 15-19.If you have an interest in this workshop pleasecontact Steve > regarding attending this years meeting. For those interested in getting introductory instruction on many of the geophysical techniques besides GPR, this would be a good opportunity. Several very well known researchers in remote sensing such as Ken Kvamme at the University of Arkansas will be instructors at this year’s workshop.

The University of Siena in Italyis having a weeklongremote sensingcourseongeoarchaeology shouldany ofyou want to attend, from July 10-18th. Several of my colleagues includingDr. Yasushi Nishimura from UNESCO Japan, Larry Conyersfrom the University of Denver, Margaret Watters from the University ofBirmingham,and Salvatore Piro from Consiglio Nacionale delle Ricerche in Rome, and myself have been invited to be instructors. It sounds like a great time and agood excuse to enjoythe Toscano landscape. http://192.167.118.99/CCGBA/laboratori/lapetlab/pagine/Xvsummer.html.

Because I have been so busy, in addition toour friends at theUS Forest Service, this years Spring workshop can not be scheduled. The next USFS GPR-SLICE workshop will definitely be in the fall. However, an informal workshop is now planned at the invitation of Dr. Bob McCullough of the Indiana-Purdue Archaeological Survey http://www.ipfw.edu/archsurv/program_details.html. Bob,and also his assistant Andy White, invitedus this yearas well as last year, tointroduce GPR to their studentsand also run a processing workshop. The workshop will begin on the evening ofJuly 31st and we will give a powerpoint presentation introductionand so willBobor his students regarding the Strawtown Archaeologicalsite. The next day will encompass doing a 1/2 day GPR survey at the Strawtown Indian site, followed by a half day of data processing in the computer lab. Another half day of data processing will be done on August 2nd, and we will end the workshop at noon that day. Bob was verykind to open up this workshop to all interested users of our software as well as any interested parties. Steve DeVore has expressed an interest to attend. We would like to invite any other users to come as well. Please contact Bob McCullough <> if you would like to attend this informal summer workshop.