Cave or Sinkhole Identification Using Ground Penetrating Radar or GPR

Ground Penetrating Radar or GPR  is an electromagnetic profiling technique utilized for high resolution mapping of subsurface features.

The technique operates on the principle of transmission and reflection of short duration electromagnetic pulses from a transducer that is moved across the ground surface.

The energy radiates down through the subsurface and reflected back to the receiving antenna from subsurface electrical discontinuities. Various in the continuously recorded returning signal are sent to a control unit for processing and display.

We use MALÅ Rough Terrain Antenna (RTA) 25 Mhz series for Ground Penetrating Radar (GPR) surveying. The unique in-line, all-in-one, antenna design provides improved performance for deeper penetration. The flexible “snake” like design allows the antenna to be maneuvered easily and efficiently through the densest or most uneven of terrain without affecting ground contact, providing optimum results in the most difficult of environments.  Max penetration is 30 – 70 meter.

The most common aquisition method in GPR survey is Radar Reflection Profiling, where transmitter and receiver anntena have a constant offset and moved on the line.

The line are prepared by separate topographic or advance team.

Crew size:

1 geophysicist, 2 Operator

2 local labour

Acquisition speed:

Depending on the measurement distance and topography, 500 – 5000 meters per day.

In the cross-section image above, it can be seen that the color contrast is different which shows the different types of different mediums, such as limestone and air in the case of cave identification. Due to the significant difference in density between the 2 mediums, the GPR signal will be seen as a large amplitude on the radargram. The amplitude on the radargram is shown on a color scale from dark blue to dark red. Thus, for the interpretation of the cave boundary that is considered a target, we look at the amplitude shown by the radargram.


Coal Exploration Using Georadar
Nickel Laterite Exploration
River & Lake Bottom Profiling


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Cave | Cavity | Georadar | GPR | Ground Penetrating Radar | Sinkhole
Terrestrial Survey

RecsaLOG provides topographic survey services and provides expert services in the field of land surveying. Specializing in coal mining and exploration, we have mixed experience in Indonesia.

Supported by the latest Total Station and GPS technology, high quality services help us maintain long-term cooperative relationships with clients. RecsaLOG operates 2 set Total Station Sokkia SET550X, 2 set Total Station Sokkia SET510, 4 units geodetic GPS Trimble and 1 unit Waterpass Leica Jogger R24.

Our survey team has more than 10 years experience in the field of conducting various types of surveys. Therefore we can guarantee topographic survey services that are highly experienced, accurate and reliable for topographic surveys anywhere in Indonesia. Output data can be GIS/CAD.

Stockpile Volume Survey


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Stockpile Volume Survey

Apart from providing topographic measurement services, RecsaLOG also provides stock volume survey services. A stockpile is a place to store or accumulate mining products such as coal, both stockpiles located at coal producers and at coal users such as factories, power plants and others. Coal stockpile may indoors or outdoors.

Stockpile measurement is included in a series of company stock-taking work that aims to calculate the volume of coal stockpiles. In principle, stockpile measurements are the same as topographic measurements, but there is further processing to calculate the volume of the stockpile. We also provide stockpile volume survey with UAV (Unmanned Aerial Vehicle) for better mapping results.

Terrestrial Survey


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River & Lake Bottom Profiling

Recsalog involves use of Ground Penetrating Radar (GPR) or so-called Georadar into a single survey used for fresh water lake and river water depth profiling, bathymetry and sub-bottom stratigrapic sediment profiling.

Radar identifies natural features such as sediment stratigraphy and interfaces, as well as natural and man-made objects including cables, pipes, boat, outboards, logs, and other artifacts buried deep in sediments.

Radar is the preferred methods when trapped gas is present in the sediment causing loss of sonar signal and for shallow waterways and lakes 0 – 3 meter depth. Radar is more sensitive as compared to sonar and can be used to detect very low density water sludge or “thick water” present at lake or river bottom. The measurement data can be converted into a 3D model of the lake or river bottom.

Coal Exploration
Nickel Laterite Exploration
Cave or Sinkhole Identification Using Ground Penetrating Radar or GPR


Follow us on Instagram: @recsalog_geoprima

Nickel Laterite Exploration

With the growth of interest in nickel laterite resource exploration, fuelled by increased demand and new processing technologies, the need for accurate resource delineation and careful mine planning becames paramount. The traditional use of borehole grids to calculate ore reserves is neither sufficiently accurate nor cost-effective at many sites due to the complexity of tropical weathering profile. Although an unconventional approach to laterite mine planning and resource delineation, georadar has shown tremendous potential for addressing project geology, resource delineation, and mine planing issues.

GPR has significantly increased the database of knowledge regarding project geology, as well as provided invaluable assistance to mine planning by imaging the bedrock weathering texture, including the precise location of subsurface pinnacle structures and fault planes. The information provided by the GPR data, in concert with strategically placed boreholes based on these data, has enabled a laterite project to be upgraded to the measured category of mineral resource.

Coal Exploration
River & Lake Bottom Profiling
Cave or Sinkhole Identification Using Ground Penetrating Radar or GPR


Follow us on Instagram: @recsalog_geoprima

Coal Exploration Using Georadar

New techniques in coal exploration develop slowly. Most of current work being done in this field relies heavily on the techniques and practices in common usage about 20 years ago.

RecsaLOG is proud to present the Ground Penetrating Radar (GPR) or so-called Georadar for Coal Exploration.

Propagation, reflection, and attenuation of GPR signals are dependent on the dielectric and conductive properties of near-surface rock units. The GPR response is kinematically similar to that of conventional reflection seismic. Imaging and intepretation of GPR data can utilize techniques of seismic acquisition, processing and displays.

Ground Penetrating Radar (GPR) that can image the subsurface profile continuously in real time have improved resolution and proving useful for Coal Exploration. GPR profile can define discontinuities in seams, faults can be identified clearly and also sedimentary layering which has contrast difference of dielectic constants.

Nickel Laterite Exploration
River & Lake Bottom Profiling
Cave or Sinkhole Identification Using Ground Penetrating Radar or GPR


Follow us on Instagram: @recsalog_geoprima