3D Topography Measurements on Correlation Cells - A New Approach to Forensic Ballistics Identifications
Jun-Feng Song, Wei Chu, D Ott, Johannes A. Soons
Based on three dimensional (3D) topography measurements on correlation cells, the National Institute of Standards and Technology (NIST) has developed the "NIST Ballistics Identification System (NBIS)" aimed to accurate ballistic identifications and fast ballistics evidence searches. The 3D topographies are subdivided into arrays of correlation cells in order to identify the "valid correlation areas" and eliminate the "invalid correlation areas" from the matching and identification procedure. "Synchronous processing" is proposed for correlating multiple cell pairs at the same time to increase correlation speed. A "Congruent Matching Cells (CMC)" method using three identification parameters of the paired correlation cells (cross correlation function maximum CCFmax, spatial registration position in x-y and registration angle θ) is proposed for high accuracy ballistics identifications. The proposed NBIS can be used for correlations of both geometrical topographies and optical intensity images. All the correlation parameters and algorithms are in the public domain and subject to open tests. An error rate reporting procedure is developed that can greatly add to the scientific support for the firearm and toolmark identification specialty, and give confidence to the trier of fact in court proceedings. The NBIS will be engineered to employ publicly available software and database file protocols, and provide published search algorithms and statistical models. In this way interoperability between different ballistics identification systems can be more easily achieved. This interoperability will make the NBIS suitable for ballistics identifications and evidence searches with large national databases, such as the National Integrated Ballistic Information Network (NIBIN) in the United States.
11th ISMTII (International Symposium on Measurement Technology and Intelligent Instrumentation)
, Chu, W.
, Ott, D.
and Soons, J.
3D Topography Measurements on Correlation Cells - A New Approach to Forensic Ballistics Identifications, 11th ISMTII (International Symposium on Measurement Technology and Intelligent Instrumentation) , Aachen, -1, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=913418
(Accessed December 8, 2023)