I also use the Reflexw software, but I did not use 3D profile, I used the "slice" command in matlab, you may try.

When you import the data into ReflexW (that is when you convert it to the internally used format), use a Geometry file (e.g. "Geometry.1") in which you have described the geometry of the survey (see page 211 in the ReflexW manual for the format of the geometry file: https://www.sandmeier-geo.de/Download/reflexw_manual_a4.pdf ). In the import menu select "geometry file" under "ConversionMode". Then process the 2D profiles. Once you are happy with a representative profile, save the applied processing sequence as batch job and apply it through "Sequence Processing" to all profiles. Then exit the 2D mode and enter the 3D module. Here you have to specify for the X- and Y-Rasterincrement the crossline and inline sample spacing, so 2.5m and whatever your inline trace spacing was. The X- and YInterpolation are the horizontal dimensions of the generated and interpolated 3D volume. When ReflexW complains about too many data values, then increase the X- and YInterpolation values. It is not meaningful to interpolate to 10cm cell size when your profile spacing was 250cm. Maybe try 50cm and 10cm. for crossline and inline spacing?

Thank you Sir,

Please have a look on the the attached result and parameters I used for 3D and 2Dprocessing.

There is clear linear feature I could see in 2D data but 3D image is not clear. The area is 22.5mx22m with Lines and cross lines at 3m interval. Even with low data scale, it is showing to decrease data scale and data value by arithmetic function.

Please advice for further improvement.

What are you trying to image? What antenna/frequencies are you using? Mapping an area of 22.5m by 22m with 3m line spacing means that you have measured a total profile length of 360 m. That‘s what you would do before breakfast to warm up. Your time window appears to be 40ns, i.e. 2m depth. You could easily measure 50x50m of area in one day with 25 cm profile spacing, that is 10km total profile length. Don‘t waste your time trying to process undersampled data. Go back and map the site properly. Your X- and YRasterincrement parameters are incorrect. They should correspond the inline and crossline GPR trace spacing. Using subsequently an interpolation of 4m in both directions doesn’t make sense. Try 3m and whatever your in-line trace spacing was for the X-/YRasterincrement and then something like 0.5 and 0.1 for interpolation. Your inline and crossline GPR trace spacing has to be in a reasonable ratio if you want to build 3D volumes.

Thank you Sir for the very helpful answer.

I have one more question:

For cavity detection, is it OK to present 3D in this way? which will be simply a reflectivity varriation. can we add any processing step in reflexw to do some kind of ampltude analysis?

Please advice the steps and references for cavity detection using 200 MHz antenna.

with normalisation before your begeins runing program.... becouse every image difrent bite