There are plans to expand the burial area at Pärnamäe Cemetery. There is a large area in the middle of the cemetery that is not in use. Historically, gravel was mined at this site, and it was later partially filled with rubbish and various fill materials. The entire area consists of three parts, two of which are lower and one higher. The cemetery administrator had information of questionable value that barrels containing approximately 100 liters of poison used to control weeds had been buried somewhere in the area under investigation decades ago.
TASK
Find 100-liter metal barrels in the area and, once found, determine their exact location and depth.
SOLUTION
To find local underground objects, the entire area must be scanned very densely. This can be done using a 2D radar with a very dense (0.5 x 0.5 m) survey grid or a 3D GPR with an antenna array. In both cases, the area to be scanned must be sufficiently flat and free of interfering objects. The entire survey area of the Pärnamäe cemetery was very uneven and covered with tall grass. In addition, the higher part was littered with rubbish and overgrown with bushes. For this reason, it was decided to initially exclude the higher part from the survey area. The remaining area was mowed and the ground leveled with a tractor. Data acquisition was performed with a high-resolution 3D GPR Raptor. Positioning was performed with a Total Station. Data post-processing was performed with special software GPR Slice.
RESULTS
The GPR survey provided horizontal cross-sections of the ground surface in the survey area. These revealed several underground objects that are likely to have been left there when the gravel was extracted. No traces of weed control agents were found in the survey area. It is therefore safe to expand the burial site in the surveyed area.
GPR survey to locate underground objects at Pärnamäe cemetery
GPR survey: anomaly
GPR survey: anomaly