SBC ПОИСК

  • Increase font size
  • Default font size
  • Decrease font size

It is considered that, as a rule, ballistic identification systems should carry out two tasks at the minimum:

  1. to build Database of objects (bullets and cartridge cases) - that is a bullet and cartridge case repository of criminal objects;
  2. to carry out (in the built database) an automated search of similar objects by marks and impressions left by rifle tools both on bullets and cartridge cases.

 

Implementation of the 2-nd task results in the ranged list of objects for further expert’s examination.

Undoubtedly, provided by the ballistic scanners, the automated search according to the matched striations on the examined objects (so called “primary” and “secondary” traces or groove marks) simplifies the expert’s work considerably. Nevertheless, the expert spends the most of his time making a correct decision on matching of the striations on the examined object with the striations of the object from the ranged object list found in the DB.

POISC system provides a number of functions making the expert’s work easier such as “ά-Channel”, “Lens”, “Transparent Overlapping”, “Area Analysis”, 2-D and 3-D modes and so on.

Nevertheless, the company is developing new functional “Applications” giving the additional possibilities (tools) for the execution of ballistic expertise.

One of these “Applications” is the “Striation Highlight” Function. It allows an expert to highlight groove marks on a black-and-white bullet evolvent image in semi-automated mode.

 

Picture 1.-the image is without “Striation Highlight” Function

Picture 2- For “primary” and “secondary” traces “Striation Highlight” Function is used.

Let us consider the number of visual advantaged shown on Picture 2 if to compare with Picture 1.  We can see:

Highlighted striations of the land mark areas give an exact idea of marks boundaries, their density and stability (repeatability) and their location relevant to each other.

For the purpose of more precise comparison the expert can choose the areas with more stable striations both on the examined object and the object from the ranged list.

For more complicated objects and for the purpose of more accurate orientation of each groove marks on both object images we can apply the method of “macro-relief orientation”

 


Picture 3a.Macro-relief marking-out(Object №1)


Picture 3b.Macro-relief marking-out(Object №2)

Picture 3c. Macro-relief fragment (enlarged)

 



Picture 4  Synchronization of two bullet evolvents by macro-relieves of the groove marks (“secondary trace”)
In some cases for better visual demonstration it is reasonable to use “Image Invertion” Function.



Picture. 5  Marks (striations) on the “inverted” image.


То make the expert’s work easier he is provided with the possibility to work  with one of the trace classes (“primary” or “secondary” traces or groove marks) or with a pair of traces (“primary” + “secondary” traces, “secondary”+ groove marks,“ primary”+groove marks)


Picture. 6  Example of highlighting of “secondary” traces and groove marks.


Picture.7 (Secondary” traces, groove marks and “primary” traces.

This function allows the expert to sort out the unwanted “noise” marks such as  marks left by bullet seating marks and not to study them  during examination.



Picture 8  Highlighting of bullet seating marks.

Besides the function will supplement the tools that POISC System possesses at the moment such as tools for measuring rifling inclination (α), rifling land width (WIL). The additional information received with this function is not only the average values (α and WIL) but such value as the distance between non-load edges and so on, which are recommended for use for the experts in the USA.

You can find more detailed information on the application of these functions in the article “The Use of Class Marks to Determine the Firearm Model”

We will continue to inform you about the works and researches the company is making, trying to improve applications for the experts’ interest.

We will be happy to answer all the questions and are waiting to your comments and recommendations.

 

Comments  

 
0 #2 profile 2018-10-31 13:03
Need cheap hosting? Try webhosting1st, just $10 for an year.

Quote
 
 
0 #1 profile 2018-10-27 19:46
Need cheap hosting? Try webhosting1st, just $10 for an year.

Quote
 

Add comment


Security code
Refresh