Interested in using GPR for graves but lack the background?
Read Dave’s success story! June 2014
Meet Dave Christianson.
He is the Cemetery Record Keeper at Grace Lutheran Church of Winchester, WI. He specifically keeps track of grave sites, family plots, and the rich history of Grace Lutheran’s cemetery. Ask Dave how many people reached the age of 100. Five. Ask him who was the first person buried in the cemetery. John Hanson. You get the picture. But not only is Dave interested in the preserving the history of the cemetery but the legacy of Grace Lutheran Church as well.
With his wealth of knowledge of the church and cemetery history, some questions still could not be answered. Some of the most important mysteries included determining the location of old burials, specifically in Block 1, Block 2, and Block 3 of the cemetery, and rediscovering the location of the first church of Winchester, the foundation being completed in 1854. So when Dave read about others hiring a geophysics company that used GPR for graves, which did not have headstones, he began to do some research and inquired about the costs of having a geophysical survey done using GPR for graves.
Dave soon realized, albeit without much surprise, that hiring a geophysics company is expensive. However, being passionate, he was not going to let this deter him. Church and cemetery history was important to him and his community; therefore, he began investigating GPR rentals. While a practical solution in theory, securing a GPR rental without a science or engineering background is not. Eventually, he talked to K.D. Jones Instruments. They agreed to provide some basic training on how to use GPR for graves. He qualified and opted for training at the start of his rental and four full days of assistance during any part of his minimum one month rental. The package also included some help with post-processing the recorded GPR records. Through this experience, the K.D. Jones Instruments GPR Basic Training and Assistance Program was born.
Brief History Of Grace Lutheran Church and Cemetery
Winchester, WI was first settled in 1846 and a congregation was formed in the year 1850 by the Norwegian settlers. Even before the congregation was organized, a burial ground was selected. This burial ground is the cemetery we see today. In the spring of 1853, it was decided a church should be built. Plans for this building stated that the church should be 40 feet long by 35 feet wide and 20 feet high with a steeple. The frame was hewed and framed from local white pine.
Sometime in the beginning of 1870, differences in opinion among community members caused 35 families to leave the congregation and create their own congregation. In 1871, construction of the second church had begun.
In 1875, it was resolved that the cemetery be divided in two equal parts.
In 1893, the second church of Winchester decided to unite with the first church of Winchester. A new church plan was drafted and accepted in January of 1903. The new church, Grace Lutheran Church of Winchester, was to be built like the Bethlehem German Church of Hortonville, Wisconsin and to cost no more than $7000. The second church was dismantled at this time, while the first church was used for services. It was completed in fall of 1903 and a wood burning furnace was installed, which had a difficult time heating the church in the severe winter. Upon completion, the second church was dissembled. Grace Lutheran Church of Winchester was further expanded in 1967.
Qualifying for the GPR Assistance and Guidance Program
Before using GPR for graves, K.D. Jones Instruments inquires about two pertinent aspects, site conditions and the operator. Thus:
1. Is GPR for graves possible? What is the composition of the land? What kind of response will the target convey? At what depth, will the target be found?
2. What is the background of the individual wanting to rent GPR? Is this person capable of interpreting GPR results with some assistance? Is this person highly motivated? Does this person have reasonable expectations? Can this person secure funds and insurance to rent GPR?
Dialogue and a consultation between an interested individual or group occurs with these questions in mind to determine if using GPR for graves is in the best interest of both parties to realize their goals.
Read more about GPR before renting.
Overview of Grace Lutheran Church’s Investigations Using GPR for Graves
Before renting to Dave Christianson and Grace Lutheran Church, K.D. Jones Instruments opened dialogue about using GPR for graves. Inquiries about Dave revealed he was a highly motivated individual with a background in surveying and house design. In addition, it was apparent that Dave possessed an eye for detail as his organization of cemetery records and history was and still is exceptional.
The composition of the cemetery consisted of sandy soils, which responds well to ground penetrating radar. In addition, Dave’s GPR targets were of coffins and vaults buried 3 to 6 feet beneath the ground. Although some of the smaller targets may be hard to locate, the vast majority of targets were reasonable, for the expected depth. Given the proximity of the survey location to a K.D. Jones Instruments’ Office, a staff member went to meet with Dave for an instrument orientation and to run several test lines to ensure that using GPR for graves would collect desirable results. The preliminary GPR records looked promising.
Dave’s Goals and Expectations
Dave’s goals for GPR were geared towards locating burial sites on some of the older plots of the cemetery. On many of the plots, family members and Dave were no longer sure whether an individual was buried behind, in front, or to the side of a monument. In some circumstances, monuments were moved from their original position in a plot and actual burial locations were not known within a family’s plot. In addition, many infants and small children were buried on a plot without a marker.
A secondary goal included locating the foundation of the first church. Miraculously, with all the detail of church history, the exact location of the first church was unknown.
However, the general whereabouts of the first church could be discerned from photos.
Process of Collecting Data Using GPR for Graves
The first day of GPR rental consisted of two staff members delivering a GPR unit (Sensors & Software Noggin 500 SmartCart) and providing an overview of basic operation and survey practices. Both helped Dave take test lines to experience how the instrument interacted over known targets. This consisted of taking line surveys with GPR over grave sites.
In addition, help was provide to install the post-processing software, showing him how to transfer files to his computer and change display parameters. Often, to obtain the best view to interpret results, variables such as scale and gain must be manipulated. With these test lines, the team helped him learn some basic GPR analysis and interpretation techniques for looking at survey lines.
Dave began by planning to run Line Surveys in front of and behind memorials in Block 1, Block 2, Block 3, and a small portion of Block 4 of the cemetery; after all, his main objective was to locate precise burial locations.
By determining a fixed starting point for every line, maintaining a properly calibrated SmartCart odometer, and possessing a survey map of every plot of the cemetery, Dave was able to match every response on the GPR to its location along the line.
Dave used the map below to keep track of his lines.
Overall, Dave collected and saved 89 lines of GPR over graves. Of which, 34 lines were run in Block 1, the oldest and least documented section of the cemetery. A staff member helped collect lines for 4 days in Winchester, WI. The number of lines resulting from running GPR over graves does not include the numerous times in which the Noggin SmartCart was operated in the run without saving mode, for reasons such as test runs and locating and marking targets.
Often in Block 3, the GPR for graves process of “run without saving” occurred to look for unmarked infant and small child graves or burials on a family plot. These burials could be anywhere on the family’s plot and therefore were not conducive to a line survey. While a gridded survey would be ideal, time constraints versus the guarantee of results forced Dave to use search and mark tactics. Furthermore, because infants and small children were often buried in pine or other nonmetal boxes over fifty years ago, these GPR grave targets were admittedly hard to find. Rather than look for a solid radar response, Dave had to develop an eye for areas that looked like dug ditches and disturbed earth in an otherwise homogenous subsurface. He quickly improved his interpretation skills.
Finding the Church Foundation
After satisfactorily using GPR for graves by collecting line data, Dave turned to some of his other goals with GPR. One of his greatest desires was to find the foundation of the first church. Old photos indicated that it was North of the present day church. Historical records also determined that the dimensions were approximately 40’x35′. Another hint lied in that, a few years ago, a foundation-like structure was found in the earth while burying someone. Thus, the location of the foundation played an important role in determining the number of available burial plots.
With this information as a starting point, Dave and a team member began looking for the foundation with GPR.
They used a number of guidelines:
First, they had an idea of where the foundation might be due to the burial a few years earlier.
Second, the foundation was a linear object that would give a strong response to GPR, much like the vaults in the ground. However, the vaults would not be as long as the foundation.
Third, the foundation should be found in areas that are not directly related to a grave.
Last, the foundation should be close to 40′ x 35′ in size.
Originally, Dave wanted to create a grid survey, measuring 80′ by 48′ with lines 24” on center to find the church foundation. However, when the team member informed him that GPR lines spaced many feet apart wouldn’t work well for locating the foundation and graves they decided against this approach. While the foundation would not be an issue, 8” line spacings would be reasonable to prevent data gaps in the GPR for graves. Furthermore, the vast amount of memorials would make a large grid difficult to accurately survey, in a short period of time. The process of mapping large areas often requires combining multiple smaller grids using the EkkoMapper software.
Again, search and mark tactics were used. Anomalous responses were marked with flags and then confirmed with vault probes ( long metal rod used to probe for vaults). Soon one whole side of the foundation was identified.
Although one side of the foundation was found, they were not sure if it was the left or right side of the church or possibly a secondary foundation. So Dave and a team member continued searching for the rest of the foundation walls. Eventually, Dave found all four sides.
After finding all four sides, Dave wanted to create a small grid to see what results from a grid looked like and to have a record for the church archives. Dave and the team member made a grid between a row of gravestones that included the South and North sides of the foundation.
The figure below identifies the area of foundation surveyed.
This grid consisted of 11 Y-lines and 54 X-lines with a line spacing of 8 inches. The data was post-processed with EKKOMapper in the Slice View. The Slice View provides nice depth cross-sections of the ground surveyed in a grid. This allowed Dave to see the beginning and end of targets as well as the response from various depths.
Finding the main foundation of the church was exciting. Next, Dave wanted to see if he could find the foundation for the church’s steeple and addition. Both of these structures were added to the church approximately fifteen years after the church was initially built. The steeple was added to the West side of the church and measured 12′ x12′ while the addition that was connected to the East side of church measured 20′ x 24′.
Processes for locating the church steeple and addition mimicked that of finding the original church foundation: search and mark tactics. However, no conclusive results could be found. Although disappointing, there is no evidence to suggest that the steeple and addition foundation would not have been torn down at some point. Furthermore, less time was dedicated to finding these structures as it was of little priority. A gridded GPR survey may have produced more obvious results.
As of now, Dave’s project is on hold. After taking all the survey lines, he used the EKKOMapper software to scale and apply parameters such as gain to each survey line to make the GPR lines more attractive. Being retired, Dave has decided to save the next part of his GPR journey for the long winter months. Next winter, he hopes to continue this project by adding family plot lines to each of the GPR for graves survey lines. He also is continually updating the plot locations of unmarked burials such as that of infants and small children to family plot diagrams. GPR Success Stories hopes to continue updates to Dave’s story as they occur.
We also would love to help you and add your story to our list of success stories!
Click here to read an interview with Dave Christianson.
Would you like to personally communicate with Dave about his experience? Contact Art@kdjonesinstruments.com to receive his contact information.