Software Features

GPR/GPS examples

Cemeteries

Archaeology

 

GPR-SLICE (c)  example images of subsurface archaeology:


The advantage of using GPR to image the subsurface is that structures at various levels within the ground can be created with special software. The raw data that comes from the GPR equipment is digital data measuring reflections along a profile that the radar antenna is pulled. The radargram is a measure of the reflection amplitudes and the travel time that the reflections take. Deeper objects take a longer for time for these reflections to be recorded. By slicing many radargram profiles collected across the site, we can see reflections at various travel times, or depths within the ground. This can be seen in the series of slices above. Slices within the ground using the radar reflection data were made every 24 cm. At the deepest level, a 6th century burial 22 meter in diameter was discovered buried beneath 120 cm of volcanic soil. The strong circular reflection is from the floor of a burial moat. This moat which was discovered at a site in Kyushu, Japan was originally built by digging material out of circular moat,as shown in the cartoon above, and then piling this soil to create a large mound. A shaft/tunnel burial was then carved out and the deceased was entombed. Over time the mound was cut by ancient farmers or erosion and buried by further volcanic eruptions at the site in the 10th century. The large round anomaly within the circular ring moat is a reflection from the burial chamber.  The complete 3D time slice dataset is available in the next YouTube animation.
The advantage of using GPR to image the subsurface is that structures at various levels within the ground can be created with special software. The raw data that comes from the GPR equipment is digital data measuring reflections along a profile that the radar antenna is pulled. The radargram is a measure of the reflection amplitudes and the travel time that the reflections take. Deeper objects take a longer for time for these reflections to be recorded. By slicing many radargram profiles collected across the site, we can see reflections at various travel times, or depths within the ground. This can be seen in the series of slices above. Slices within the ground using the radar reflection data were made every 24 cm. At the deepest level, a 6th century burial 22 meter in diameter was discovered buried beneath 120 cm of volcanic soil. The strong circular reflection is from the floor of a burial moat. This moat which was discovered at a site in Kyushu, Japan was originally built by digging material out of circular moat,as shown in the cartoon above, and then piling this soil to create a large mound. A shaft/tunnel burial was then carved out and the deceased was entombed. Over time the mound was cut by ancient farmers or erosion and buried by further volcanic eruptions at the site in the 10th century. The large round anomaly within the circular ring moat is a reflection from the burial chamber. The complete 3D time slice dataset is available in the next YouTube animation.
GPR-SLICE subsurface images can help to distinguish real archaeology from surface disturbances which may propagate to depth. It was often said in GPR surveying that the top 5-10 centimeters of the ground surface was lost due to reverberations and strong ground-surface waves. The people that claimed this were the old generation which never examine time slice images and only relied on radargram profiles. Shown in the diagram is a survey at the Futenma Marine Corps Air Base in Okinawa, in a search for perhaps an ancient castle site. Buldozer marks can be seen on the ground and are easily detected by GPR-SLICE imaging. The bulldozer marks can also seen to have been recorded at deeper depths as a result of soil compaction.
One of the unique options in GPR-SLICE is to create topographic as well as horizon slices. In this particular example at the Saitobaru National Burial Mounds in Miyazaki Prefecture, a 6th century AD mound was surveyed. An underlying volcanic layer was evident throughout the survey site and was known to be flat. The layer was adjusted to be flat using a Static Corrections menu. The process naturally can predict surface topography in this instance without knowledge of the mound contours. The primary utility of the horizon correction however is to be able to find anomalies within a varying 3D surface. For instance, looking for pit dwellings in ancient living surfaces which are not flat are easily detected on horizon slices. Level flat slices have problems in that artificial reflections due to stratigraphy make there detection more difficult. (Photo courtesy of Noriaki Higashi, Miyazaki Prefectural Archaeological Dept.)
GPR-SLICE software was instrumental in helping to locate chamber burials excavated into hard volcanic soils. 2 such burials were discovered from the ground penetrating radar survey. A 3D amplitude render of the site indicated that 2 chambers existed and afterwhich they were subsequently excavated. A protective roof was recently constructed over the site to protect these locally rare burials. (Photo courtesy of Noriaki Higashi, Miyazaki Prefectural Archaeology Dept.)
Prior to excavation at Kofun Burial Mound #13 (Saitobaru, Miyazaki Prefecture, Japan) complete GPR survey was made to ascertain the condition and location of any remains on the upper portion of the mound. GPR-SLICE time slice analysis indicated a longitudinal burial orientated 45 degrees to the main axis of the 80m keyhole shaped burial. Excavations later verified the information obtained from GPR surveying.
A 500 MHz GPR survey at a 8th century site was expedited in hopes of discovering remnants of a womens temple in Tokushima Prefecture, Japan. Some rectangular structures imaged at the site may indicate several possible locations for buried foundations. The foundations at the site primarily are composed of earthen filled postholes with some postholes laiden with stones.
Pantel del Cueto & Associates commisioned a survey in downtown Mayaguez, Puerto Rico.  The purpose of surveying this urban environment was to detect subsurface archaeology and to locate old utilities.   Several areas during road work revealed historic cistern as well as rubble from earthquakes.   GPR surveying was made to faciliate the discovery of unknown utilities as well as to find remnants of structures from an early 19th century Spanish plaza.  GPR renders indicate the location of unknown utilities and some older sidewalk boundaries.  In the GPR render, the vertical anomalies are storm drains in which sewers can be seen to connect to below the main plaza street.  This work was made possible by the support from the Directorate of Urbanism, Puerto Rico Department of Transportation and Public Works.
Pantel del Cueto & Associates commisioned a survey in downtown Mayaguez, Puerto Rico. The purpose of surveying this urban environment was to detect subsurface archaeology and to locate old utilities. Several areas during road work revealed historic cistern as well as rubble from earthquakes. GPR surveying was made to faciliate the discovery of unknown utilities as well as to find remnants of structures from an early 19th century Spanish plaza. GPR renders indicate the location of unknown utilities and some older sidewalk boundaries. In the GPR render, the vertical anomalies are storm drains in which sewers can be seen to connect to below the main plaza street. This work was made possible by the support from the Directorate of Urbanism, Puerto Rico Department of Transportation and Public Works.
At another survey in Puerto Rico, the oldest standing European structure anywhere in North or South America, the Iglesia San Jose church was studied. This 16th century structure is undergoing complete restoration over the next decade. The purpose of the GPR survey is to provide the engineers and conservationists subsurface information that could impact the restoration process. The results from imaging indicate the location of known crypts beneath the tile floors. Another square reflection, located between two standing pillars of the church, suggest the location of yet another hidden crypt in the church. Additional analysis of the time slice data using different gaining transforms, the overall strong reflections recorded on the east side correspond to water damage to the subsurface foundation beneath the church.
Surveying over sites that have significant topography, can distort the recorded radargram. Typical elevation corrections only apply the vertical topography to the radargrams (middle diagram), but do not take into account the ground slope and the tilt of the antenna. A radargram that is corrected for not only topography, but also the ground slope (bottom figure) is shown. GPR-SLICE Software has a static corrections menu that allows the user to correct radargrams for topography and ground slope, yielding more accurate subsurface imaging. It should also be noted, that the static corrections batch processes actually create statically corrected binary radargram files which can be used in other data processes.
 
A GPR survey at Chersonesis in the Ukraine was expedited in 1998 at the request of Joseph Carter at the University of Texas, Austin. Evidence of an ancient Necropolis was the object of the survey. Several interesting anomalies were detected and drilled. Unfortunately, these ancient burials have yet to be discovered at the site.
Recent results of GPR-SLICE imaging at Wolseong in Korea  are shown in the above diagram. The survey, conducted with Dr. Hyun Dok Oh of the National Research Institute for Cultural Properties and Dr. Yasushi Nishimura from UNESCO in Nara Japan, indicates regularly spaced reflections of subsurface basestones used to support columns of the ancient Silla Kingdom.
Recent results of GPR-SLICE imaging at Wolseong in Korea are shown in the above diagram. The survey, conducted with Dr. Hyun Dok Oh of the National Research Institute for Cultural Properties and Dr. Yasushi Nishimura from UNESCO in Nara Japan, indicates regularly spaced reflections of subsurface basestones used to support columns of the ancient Silla Kingdom.