GPRS Helps Boats Safely Enter Harbor in Pago Pago, American Samoa

Ground Penetrating Radar Systems, Inc. (GPRS) was contacted by a well-known general contractor based in Hawaii, as well as many of the US territories, to locate the structural steel in four concrete pillars. These pillars were designed to hold a large tower that housed a light that when lined up with another lighted tower on the mountain side, would guide boats safely into the harbor and miss the shallow reef in Pago Pago, American Samoa.  These types of lights are able to be seen for miles out in the sea when in use.  Because of the light needing to line up with the light on the tower on the mountain, it was critical that all structural steel was located so the tower could be engineered properly, allowing them to get the placement within 3cm of the original light. The contractor was on an extremely tight schedule due to the sensitive nature of the tower and safety for all those traveling in and out of the harbor.  The scanning was completed on time for the tower to be constructed and in place in the time required by the large, international organization that requested the work.

Ground penetrating radar is a great tool to scan areas of post-tensioned cables, rebar, and conduits, including PVC pipes. Ground penetrating Radar can also be used for locating underground utilities such as water, gas, electrical, communication, sewer, underground storage tanks and associated piping, and other objects prior to digging or excavating. Please contact Ground Penetrating Radar Systems – GPRS to learn how we can assist with your next project. Ground Penetrating Radar Systems has performed countless jobs like this throughout California and Nevada and also services the entire United States. If you would like to schedule an appointment in Northern California or Northern Nevada, please contact Mike Brown (Regional Manager) by phone at 916.539.6492 or by email at: Contact us today for an estimate, or if you have any inquiries for your next project.


Void Scan | La Porte, TX

A major Petro Chemical plant in La Porte, TX contacted GPRS about performing a GPR scan to search for sub surface voids during their turnover of the existing water cooling tower. The client had been concerned about sub surface wash out as they were installing additional concrete piers to support the new water tower installation. We used the 1600 MHz antenna and the 400 MHz antenna to effectively locate the void locations by searching for the separation of the bottom of the slab and soil. GPRS was able to determine the location of the sub surface voids in all three of the concrete catch basins, thus helping the client determine the most efficient way of fixing the washout beneath the slab.


To learn more about the capabilities of GPRS in the South Texas Gulf Region, contact Project Manager Jim Cardoza at 713-253-7072 / or Nate Loyola at 832-262-3438 /

Locating Underground Utilities in Kansas City, MO

Ground Penetrating Radar Systems of Kansas City was called to locate any underground utilities at a site in Independence, MO.  The client was going to be trenching in new power and was concerned about striking existing utilities. The technician was able to locate multiple utilities that could’ve been struck while trenching. Thanks to GPRS the client was able to safely perform his work without any issues.


GPRS’S use of multiple utility locating technologies can help assure you are getting the fastest and most reliable locate for your next project. GPRS can assist you with all of your locating needs.  Whether you are excavating, boring, or trenching GPRS is your locating solution. Using GPRS will not only save time and money during construction, it can also save a life. Ground Penetrating Radar Systems of Kansas City can assist you in your projects in St. Joseph, Lawrence and Topeka.  For more information about GPRS capabilities or questions on how we could assist you on your next project please contact Terry Jeffries at or 913-232-6533.

Correcting the Competition

We received a call today from a new customer who had recently hired one of our competitors to scan for his plumbing penetrations. He was concerned with the output of the first scan and wanted a second opinion, because some of the markings didn’t seem to add up. We told him we would provide a second opinion, and only charge him for the trip if we were able to offer new, relevant information that kept his team safe.


After beginning the scan it became immediately clear that our competitor had made some sloppy mistakes. In the image above, you can see my markings in black marker and our competitor’s earlier markings in red crayon. Our competitor had missed the fact that one of the lines ran at a slight diagonal (about a 15º angle). He marked the line as through it were straight, and as a result, his marking were off by up to 4” at the far end. Consider also the example below. Again, my markings are in black marker, and our competitor’s prior markings are in blue.

Evidently, this particular competitor seems to have rushed the job, seemingly only scanning over each line once, rather than scanning in 3 or more successive locations in order to verify the direction and continuation of each line. It is also confusing that the other scanner included at least 4 or 5 false positives among his markings—lines that weren’t actually there. The customer looked over my shoulder as I scanned, and exclaimed “that area is completely clear! Why did he mark there?” My only guess was that he wanted to indicate the extent of the scan area, but this left the customer with a false picture of his available options.


I can’t speak to the other company’s reasoning, and I’m not sure what caused the persistent error in many of their markings, but I was thankful for the opportunity to provide a more accurate picture to our new customer, who indicated that our price was the same as the one he had previously paid. Needless to say, the customer told me at the conclusion of the job that we would be his new GPR crew, and that is a stewardship that is an honor to receive.

Scanning the University of Tennessee Strength & Conditioning Gym


The GPRS East Tennessee office was subcontracted by an engineering firm out of Knoxville, TN to scan the University of Tennessee Strength & Conditioning gym in Knoxville, TN at their indoor sports complex facility.  The firm was interested taking soil samples for analysis to determine if the subsurface could support additional weight for an expansion project.  There were 6-7 locations that needed to be scanned with ground penetrating radar so that underground utilities, conduits, and reinforcing steel would not be struck when the drilling took place.  The GPRS representative used a GSSI 1600 MHz antenna and a radio detection wand to scan these 6-7 locations.  Each location to be drilled was scanned in a 3’x3’ radius, and bordered with blue painters tape on the surface so the drilling contractors could better understand the exact boundaries of each area scanned with ground penetrating radar.  There were conduits found on this site under the slab, and upon location, they were marked on the surface with painters tape indicating what type of utility was encountered.  The concrete slab was determined to have a layer of wire mesh to add reinforcement.  Depths were provided if located with ground penetrating radar.  All findings were reviewed with the site contact after the ground penetrating radar inspection and any locations that had to be moved due to utilities in the direct path were communicated with the site contact.  Details of the inspection were also reviewed with onsite personnel so that they could update their site drawings for their records.


The 1600 MHz transmits an electromagnetic pulse through the ground and displays the reflection on a SIR 3000 head unit for interpretation.  This antenna allows for ground penetrating radar signal penetration of 18”-24” through concrete.  Our depth penetration is greatly determined by the age of the concrete as well as the amount of reinforcing steel present.  Radio Detection RD-7000 locator is a device that detects live power and RF signals underground, allowing us to locate electrical or telephone lines even if they are below the minimum size requirements to be detected by ground penetrating radar.  It also allows us to detect utilities via frequency induction or conduction with an exposed or known surface of the conductive utility.

Urgent Request Met By GPRS Technicians At Pittsburgh International Airport

Ground Penetrating Radar Systems (GPRS) Inc. was contacted to locate underground utilities by a construction company that is completing an overhaul of the communications and power stations around the Pittsburgh International Airport.

An urgent request was made by the contractor to have a same day underground utility locate done, and with over 150 GPRS technicians across the country, the request was met by the GPRS technicians out of Pittsburgh.

The job required the location of an underground power line that would be tapped into and run directly to the energy shelter to reduce redundancy and material.  Ground Penetrating Radar (GPR) along with passive and direct connect radio detection were used to locate the power line and the communication lines that crossed through the prospective trench dig path.

The GPR and direct connect radio detection methods were able to accurately locate the position of four underground lines that would impact the project.  Along with location, GPRS technicians were able to determine the depths of the lines as well.  Knowing the location and depths of the lines helped the contractor save time and eliminate potential stress, injury and additional costs for this project.  Communicating with the contractor and documenting the utility locations with clear and accurate field markings and site photos were helpful methods to ensure the safe completion of the project.


In construction, professionalism is everything, and completing your projects without incidents can make or break your bottom line. When you are excavating, it is important to have the utilities privately and publicly located. Utilizing GPRS for your project will help reduce injury, reduce lost productivity, and maintain incident-free professionalism that your clients demand.

GPRS uses the latest and greatest technology to locate power lines, fiber lines, water lines, UST’s, storm drains, and sewer drains under the surface. Utilizing GPRS on your project can help mitigate costly repairs, prevent severe injuries, and also maintain the integrity of your project.

Ground Penetrating Radar Systems of Pittsburgh is available to service the private utility locating and concrete scanning needs of Western Pennsylvania.

Concrete Imaging Technology Utilized to Locate Conduits and Reinforcing Prior to Core Drilling at a Verizon Headquarters in Hyannis, MA

A general contractor had a project inside of a Verizon Office where he needed to install Fios lines and push them through two 7 inch core holes within the building.  It was essential, while core drilling the concrete, not to compromise any conduits or utilities within or beneath the slab. Prior to beginning the core drilling process, the contractor contacted Ground Penetrating Radar Systems of New England to scan the floor in order to locate all of the conduits and utilities that ran through the area and to locate any reinforcing in the floor. GPRS used a High Resolution 1600MHz Antenna that is able to scan concrete up to 18-22” in thickness with incredible accuracy of +/-1/4” on the location and depth of the anomaly.


After all of the conduits, utilities, and reinforcing were found around the proposed core holes, the general contractor had all of the information needed to proceed with confidence and safety. With the help of Ground Penetrating Radar Systems, Inc. this project stayed on schedule and was safely completed without any damage to conduits or the individuals coring the hole locations. If you have a project where you have concerns about striking reinforcing steel, conduits or post tension cables contact your local GPRS office to ensure your project is kept on time and done safely. Your local technician can be found at

To learn more about the capabilities of GPRS in Massachusetts, Rhode Island, New Hampshire, Maine & Vermont, contact Regional Manager, Mark Johnson, at 617.448.8098 or