Analyzing and Editing 3D Scan Images

Before conducting any geophysical measurement you have to know what kind of objects or cavities you are looking for and if the area you choose is suitable for this procedure. Measuring without a plan will not give you the results you are expecting.

Prior to performing a scan, ensure that you have chosen a suitable site where you believe an item to be. Blindly searching an area may produce undesired results. For this reason, please note the following instructions:

After conducting the geophysical measurement according to the previous hints and our Ground Scan Guide, the recorded scan data needs to be analyzed. In the following sections all necessary information concerning 3D scan analysis will be provided.

Proper data analysis is necessary when working with any geophysical instrument. Properly configuring the software as well as taking in all necessary factors of the terrain is important to the analysis of the given information.

Looking at the graphic for the first time

Think about what it is that you are looking for. Are you looking for a tunnel? Did you do the right kind of scan to detect a tunnel?

When you are looking for a metal chest or steel box, the first sign on the scan should be a red or orange area that is isolated. If you are looking for a tunnel the scan must be much larger and you will be looking for a blue area, and these color differences are usually very strong from one to the other. Generally speaking, one needs to look at all the colors and also the shapes. Because the unit does work with the naturally occurring magnetic fields, the poles may actually reverse so red is blue and blue is red.

The final result from the given colors if it will be red or blue may lie on the following factors:

Color Definition

Under optimum conditions the colors can quickly assist you in finding and identifying the sub-surface object as well as what it is made of. There are occasions when the soil may have be more mineralized than in other areas. Normally speaking the colors mean:

As a note, an important element that can be quickly realized via the colors are metal objects made from iron, cobalt and nickel for they are very magnetic. These metals almost always will have a strong positive (red) pole and a strong negative (blue) pole.

Mineralized soil is also an important factor to take into consideration. We mentioned earlier in this manual about making control scans. When you scan an area for example three time over the same starting and stopping points, remember this basic rule, “Real Targets Don't Move!”. If in your second and third control scans you realize that nothing is staying in the same place, most likely there is nothing there and you are looking at a patch of mineralized soil.

Ferromagnatic signature in OKM Visualizer 3D Studio
Figure 1: Ferromagnatic signature in OKM Visualizer 3D Studio

In figure 1, a typical ferromagnetic signature is shown. It is not difficult to know the exact characteristics. The red and the blue directly next to one another is the key. Normally the colors will have approximately the same size and shape.

Recognizing the background color

When viewing a scan, try to see which color is dominant throughout. This is your background color that defines your "normal" soil. In standard soils, it will typically be green with some lighter and darker shades. There are conditions where the color may be completely different like blue. This may happen in different soil conditions that have stronger mineralized soils.

Search for anomalies

After you have established what the background color is, now it is time to look for the anomalies. If you see a distinct color difference this may be a possible anomaly. It will be very recognizable from the background whereas when rotating and viewing the suspect will be a large difference.

You can also view the scan from the side. At this point you will see that the difference is so great that you will have to zoom out in order to see the entire scan. This is a time when a control scan needs to be performed to ensure that there weren't any errors made in the first scan. As is often stated, it is important to remember that real targets do not move.

Now there is also the possibility that you have a scan that has a lot of different colors all at the same time. This usually occurs when one is looking at completely normal soil without any significant properties.

Void Interferences

There are outside forces which can cause interference to your signal. For example some of these interferences are caused by being too close to a radio station, bad weather including lightning, being too close to high powered electrical conduits, ground radar from an airport, high powered speakers and magnets to name a few. These errors you can see in your scan results. Normally these signal interferences can be quickly identified by a single strong spike within the scan often turning the entire scan a dark orange or red color. The signal can be corrected within the Visualizer 3D Studio software.

Position of an anomaly within a graphic

Should you find an anomaly, it is important to situate the anomaly within the middle of the scan and not on an edge. Also you must be able to differentiate it from the background color. This way you will be able to identify the exact location of the target.

If you find an anomaly only on the edge of a scan, change the size of your scan so that the area scanned is including the suspect area. Only when a target is directly in the center of a scan, can a proper analysis be made.

Metal object or mineralisation

At the very beginning it is not always easy to find out the difference between metallic objects and mineralization. Generally, metals are represented in reddish colors, but mineralized deposits in the ground can also include red color signals.

When you come across an area where you see darker oranges and reds in the scan, it is important to determine if it is indeed a metallic object or if the ground is highly mineralized. Naturally soils that are highly mineralized will quickly be known for all the scans in the area will show nearly the same.

For the beginner this can be very frustrating to decipher the difference. And there are even areas of soil which have high concentrations of iron that will show red. This is where the control scans are imperative, take care as to all of the details during a control scan to ensure that it is performed properly.

Here are some important notes how to distinguish a real object from a mineralization (please take note that the following information are based on the usage of the standard color scheme "Red-Green-Blue"):

Please read section Modifiers to get more information about how to detect mineralization with the modifier functions!

Additional tools for Data Analysis in Visualizer 3D Studio

The Right Sidebar of Visualizer 3D Studio offers various options that help to analyze and optimize your scan images.

Soil Types Soil Types
Applying the proper soil type is one of the essential keys to determine the correct depth of potential objects.
Read more ...
Scan Information Scan Information / Characteristics
Another important step is to apply information regarding the scan field itself (e.g. field length and width).
Read more ...
Bookmarks Bookmarks
It might be helpful to set markers or bookmarks at special scan points to add important notes (e.g. for any PDF Report generation).
Read more ...
Modifiers Modifiers
Special modifiers or mathematical algorithms can by applied to optimize and improve the collected scan data.
Read more ...
Visualization Visualization
Besides mathematical improvements that are changing the scan data directly, there are many options to improve the visual representation of the scan image without changing scan data.
Read more ...

Transformations / Views
Many transformation functions can be used to move, scale or rotate the scan image to get the best view of all the scan data.
Read more ...

In addition to the information in this documentation OKM offers individual training for Detectors and Software Analysis.

OKM 3D Software Training OKM Expert and Trainer Frank explains how to operate the OKM detector software
OKM Detector Training OKM Expert and Trainer Frank Casser on site with OKM Gepard GPR 3D
OKM Scan Analysis OKM Scan Analysis

Find your perfect OKM detector