In 1832 there were 57 Irish immigrants who arrived in Philadelphia to work on the rail lines and partake in the American dream who mysteriously disappeared. They were hired by a fellow Irishman right off the docks when they arrived. It was reported originally that 8 weeks after their arrival all died as a result of cholera pandemic and buried in a mass grave.
For years there were rumors and stories about how these men came to their demise. These stories of possible murder had transformed into a local legend. Until 2002 when two grandsons of an old railway worker decided to explore this mystery further. They conducted an archaeological dig at the site of the Irish workers’ camp. After uncovering over 1,000 artifacts the remains of the men continued to elude them.
Human skull with a hole found in mass grave.
It was in 2007 they started to employ the services of a geophysicist and ground penetrating radar equipment to try to uncover the mystery. For the next few years they continued to process the GPR data uncovering many more artifacts and in 2009 they finally found human remains. Since then an anthropologist from the local university has identified seven skeletons and 4 human skulls. One appeared to have a bullet hole in it and many others showed signs of blunt-force trauma.
Investigation has found there was a local break out of cholera which killed many in that area. It is suspected that local vigilantes killed the other workers, who were also thought to be possibly infected, for trying to escape the pandemic. Once all the remains are uncovered they will be taken to their final resting place in a cemetery where many Victorian elite of Philadelphia are buried.
Posted in Forensic Locating Gravesite Locating by .
Although this is not our area of expertise I found this news release fascinating. What caught my interest was that ground penetrating radar technology (GPR), which we use every day for geophysical surveys, to locate utilities underground, for concrete imaging, cemetery mapping and also forensic locating, is now being used to locate Improvised Explosive Devices (IED) in Afghanistan.
These IEDs have claimed thousands of lives of U.S. and Canadian soldiers and destroyed millions of dollars worth of military ground vehicles. On August 5th soldiers were trained on how to operate the Husky-Mounted Detection System. The training included locating metallic and non-metallic IEDs and mines similar to real route clearance missions that they will experience in the field.
This Husky vehicle is mounted with 4 large ground penetrating radar panels, computer and monitor. These heavily armored Husky vehicles were previously mounted with metal detectors. Now the new GPR system provides the operator 2D & 3D views of objects buried in the ground. Instead of just listening for a beep from the metal detectors the operator can actually see it in the ground.
Various ground penetrating radar systems have been utilized successfully on missions for route clearance since 2008. However, none as advanced as this. The course instructor said their current plan is to have nearly 200 of these Million Dollar GPR systems in operation in Afghanistan by May 2011.
Some may questions the Million Dollar price tag. But how do you put a price on saving lives!
Posted in New GPR Products Unique GPR Applications by .
I realize August may seem like a strange time of year to be writing about Ice Roads. While we are enjoying one of the hottest summers on record plans are being put in place to ensure the safety of all those who have to cross large bodies of water to reach extreme northern remote communities this coming winter.
Ice roads and ice runways are commonly used for transportation in Northern Canada, Alaska, Northern Europe and Russia. These isolated communities and mining sites depend on the ice roads being secure in order to transport people and products they need to survive during the winter.
In the North West Territories they open shortly after the initial freeze in November and close just before the ice thaws in April. During this time vehicles weighing sometimes more than 50 tons (45,000 Kg) in weight are driven across these ice roads. At an average speed of 20 miles per hour over ice roads some trips take more than 20 hours one way.
To ensure the safety of the trucks traveling on these ice roads Ground Penetrating Radar (GPR) is used to collect the data necessary to confirm the thickness of the ice (usually a minimum of about 27 inches). The GPR antenna is mounted on a sleigh and pulled behind a pickup truck or snowmobile. The antenna is connected to a computerized digital video logger (see below) in the vehicle allowing the GPR technician to see the ice thickness in real time.
Sensors & Software DVL Display
Color Coded Ice Map
This GPR data is saved and combined with exact GPS data (collected at the same time with an integrated GPS system). The data is then analyzed and interpreted by software which creates a map of the ice thickness for the entire stretch of the road. These ice road maps show the different ice thicknesses by color code making it easy to see the sections of the road that may be potentially dangerous.
To ensure the safety of the truck drivers, the ice thickness is measured weekly or even daily as the need dictates. No doubt this technology has saved the lives of countless people bringing supplies to the remote areas of the north.
This same technology could be used to map the ice thickness of our lakes and rivers which are used by ice fishermen and snowmobilers in the winter months. However, I’m not aware of any recreational communities currently utilizing this life saving technology. Perhaps it’s because these weekend activities are not deemed necessary for the survival of that community. It’s unfortunate they do not seem to be willing to invest in a technology that could save the lives of many recreational fisherman and snowmobilers.
Posted in Geophysical Survey Ice Road Mapping Unique GPR Applications by .
Jul 10
27
GPR 2010 Conference
The Institute for Archaeological and Monumental Heritage IBAM-CNR, the Department of Innovation Engineering and the Department of Science of Materials of the University of Salento hosed 13th International Conference on Ground Penetrating Radar June 21st – 25th in the historic city of Lecce, Italy. The latest developments in GPR technology were presented to about 200 attendees in a beautiful old stone castle.
Technical workshops and presentations included topics such as new approaches for efficient and cost-effective 3D GPR investigations and the trade-offs between GPR and other non-destructive testing techniques. In addition to the expected application areas such as geological, concrete infrastructure and archaeological discussions also included glaciological and planetary exploration uses of GPR. However, I’m not sure we are ready to expand our services to other planets just yet.
GPR instrument makers showed off their latest products in field demonstrations. One of the demonstrations allowed attendees to see 3D imaging over a natural archeological site. After the demonstrations the attendees had social time to mingle and exchange ideas over cocktails and dinner and for some that lasted late into the night.
The overall concensus seems to be that the conference was extremely informative and interesting. The next GPR conference is scheduled for 2012 and will be held in Shanghai, PRC.
Posted in GPR Conferences by .
We are often asked “what is the difference is between Public Utility Locating, Private Utility Locating and Subsurface Utility Engineering. It’s confusing to many because the basic purpose, which is to locate utilities subsurface, is the same but to varying degrees. The purpose of this post is to try to clear up the confusion.
Public Utility Locating
This is commonly known as a basic “Utility Locate” and is required by law in most regions prior to any excavation. It is used to mark specific utility lines owned by a public utility company prior to excavating. These locates are generally conducted by your local utility companies at no cost to you. To help you coordinate the various utility locates you may only need to call a “One Call” or “Call Before You Dig” service in most areas.
A utility locator will mark the approximate horizontal location of that company’s buried utility. In most cases they will only mark utilities leading to a private property. Also, they do not mark all lines. They will only mark the utilities that belong to the companies they represent. Basic electromagnetic (EM) locators are used to trace the approximate location of the line. This is marked on the surface with paint or flags as per the standard utility color code.
Private Utility Locating
Private locators take utility locating to the next level. In addition to EM technology they use Ground Penetrating Radar (GPR) to locate utilities. The primary advantage of hiring a private utility locating service is their ability to locate all buried lines. This includes lines on private property that may have been installed by a contractor in addition to the ones installed by the utility companies.
By using GPR they are able to not only accurately locate the horizontal position of the line but also the exact depth. GPR technology is also able to locate plastic, fiber optic, cable TV lines, water and concrete sewer lines. The depth of penetration of GPR equipment is determined by the soil type.
The GPR equipment saves the subsurface imaging data which can be used to accurately map the location and depth of all the lines on a site plan for future reference. Since paint on grass can be mowed and flags can be removed this can be beneficial if the excavation is not conducted immediately after the utility locate has been completed.
Subsurface Utility Engineering
This is a mainly non-destructive engineering process that includes civil engineering, subsurface geophysical surveying and mapping, vacuum excavation and utility asset management technologies to identify and classify quality levels of existing data and maps the locations of underground utilities. They use original as-builts site plans and private utility locating data for design purposes. They may also use vacuum excavation or bore holes to confirm the location and depth of the utilities.
This information is most useful during the design phase of construction. If data reveals the existence of a utility conflict the engineers can develop a more viable design or alternatives to relocate the utilities. These changes can result in cost savings by moving the excavation away from the utilities during the design phase.
Summary
These 3 different alternatives to locating subsurface utilities offer different levels of information at different levels of cost. You will have to make the decision which service is most appropriate for your application and level of risk you are willing to take when excavating.
If you require more information you can contact us or visit our Utility Locating web page.
Posted in Utility Locating by .
Jun 10
28
GPR used on Mars
Science News has just revealed that scientists previously felt a natural force had recently carved pinwheel shaped troughs and a canyon near the north pole on Mars. This theory could not be tested beyond what they could see on the surface of this planet. That is until now.
The origin of this spiral canyon was recently revealed to have been formed over an extended period of time with the use of ground penetrating radar. GPR technology, carried by 2 Mars orbiters, was used to take images and revealed the layers within the walls to assess the extended time it took to form the canyon.
The scientists took 2-D cross-section GPR images of the troughs which revealed the layers in the walls showing the history of the canyon formation. GPR also traced reflective markers following the geometry of these underground formations to build a 3-D sense of the layers.
Although the GPR study didn’t answer the question of what changes in the atmosphere on Mars were responsible for the formation of the canyon and spiral troughs it did give the scientists an understanding of the timing of this process. This information may lead to more evidence based climate models for the red planet.
Posted in Geophysical Survey Unique GPR Applications by .
This headline was taken from the CBS News web site because I thought it was important to share this scandal with the readers of our blog. With today’s ground penetrating radar technology and computerized cemetery mapping systems there is no reason for what this probe has found.
Apparently the investigation by the Army’s Inspector General reveals a “dysfunctional management system” at America’s most sacred burial ground. How can an organization with the type of resources available to them not have the most sophisticated cemetery mapping system in the country?
About five incidents have been identified in which remains were misplaced – starting with a casket found where there was supposed to be an empty grave to also moving remains without the permission of next of kin. A review of Arlington’s filing system has found 200 cases in which they can’t account for the location of the remains. As a result, it has been indicated, ground penetrating radar will have to be used to map the missing gravesites.
Visit our web site if you would like more information about how ground penetrating radar is used for cemetery mapping.
Posted in Cemetery Mapping Gravesite Locating by .
This is our first blog post and I thought I would start with a unique ground penetrating radar application. Our company was commissioned to conduct an environmental survey to locate a prairie rattlesnake habitat (hibernacula) where an endangered Alberta rattlesnake makes its winter home.
The reason it was important to locate this subsurface habitat was to confirm that a horizontal bore for pipeline construction in that area would not interfere with the Rattlesnake’s winter retreat. In order to determine the location of the habitat our ground penetrating radar service was selected because GPR technology is non-invasive and can accurately pin point and map the location and depth of the underground hibernacula without disturbing the sleeping rattlesnakes.
A Chilling Experience
To complicate the task this environmental survey was to be conducted during the middle of winter in minus 40 degree Celsiustemperatures. It was decided this was the best time of year to search for the hibernacula because it was during their hibernation period (primarily for the safety of the rattlesnake and our GPR technicians). The good news is we did locate the rattlesnake habitat and they were all sound asleep!
The data was collected in the field using a 500 MHz GPR antenna for analysis then interpreted using specialized 3D software in our lab to map the survey. An area approximately 300 meters by 22 meters (985 ft by 72 ft) was defined. Using a global positioning satellite (GPS) system each of the corners of the grid areas was located for accuracy.
In conclusion Global GPR Services, using ground penetrating radar was successful in identifying the size and location of the Prairie Rattlesnake hibernacula. The use of GPR as a non-destructive testing (NDT) technique to assist in locating subsurface animal habitats was proven to be effective with no harm to the environment or the habitat.
If you would like more details about this project you can click >>> Environmental Assessment of Rattlesnake Habitat for our white paper.