ABSTRACT The National Institute of Standards and Technology is developing reference standards thr... more ABSTRACT The National Institute of Standards and Technology is developing reference standards through its Office of Law Enforcement Standards with funding provided by the National Institute of Justice. The standard reference materials are used by crime laboratories to verify that results obtained when using their protocols and methodologies meet legal requirements and that equipment is operating properly. The NIST Reference Materials 8240/8250 standard bullets and casings is an example of materials that will assist laboratories in calibrating their instruments and ensuring quality control.The Office of Law Enforcement Standards (OLES) at the National Institute of Standards and Technology (NIST) manages research in many different disciplines of forensic science. One of these projects supports the National Integrated Ballistics Information Network (NIBIN). NIST digitized six bullet signatures from samples provided by the Bureau of Alcohol, Tobacco, and Firearms (ATF) and the Federal Bureau of Investigation (FBI). Using these signatures as a virtual standard, NIST’s Instrument Shop manufactured 20 reference materials (RM) 8240 standard bullets using a numerically-controlled diamond turning machine. Test results show high reproducibility of the bullet signatures on standard bullets. NIST has also developed a new parameter for bullet signature comparisons, using autocorrelation functions, and proposed a diagram for tracing local ballistics measurements to the National Laboratory Center of the ATF and to the FBI. Using an electro-forming process, NIST has manufactured prototype standard casings and test results show high reproducibility for the casing signatures.
This is an analysis of standards related to dimensional metrology, with recommendations regarding... more This is an analysis of standards related to dimensional metrology, with recommendations regarding standards development. The analysis focuses on the degree to which existing and developing standards provide a complete set of non-overlapping specifications for information needed to perform dimensional metrology. The analysis identifies four major software systems and their interfaces. It also identifies 15 dimensional metrology activities, each of which is expected to correspond to a software module. The major systems are made up of sets of modules. Twenty-two application programming interfaces and data formats for dimensional metrology are identified and discussed. The analysis also discusses issues regarding languages in which standards may be written.
Advanced Characterization Techniques for Optics, Semiconductors, and Nanotechnologies III, 2007
Based on the cross-correlation function (CCF), a new parameter called profile difference, Ds (or ... more Based on the cross-correlation function (CCF), a new parameter called profile difference, Ds (or topography difference for 3D), is developed for measurement and comparison of 2D profiles and 3D topographies. When Ds = 0, the two compared profiles or topographies must be exactly the same (point by point). A 2D and 3D topography measurement system was established at the National Institute of Standards and Technology (NIST), that includes data acquisition stations using stylus instruments and a confocal microscope, and a correlation program using the proposed parameter Ds and the cross-correlation function maximum CCFmax. This system has been used for 2D and 3D ballistics signature measurements of the NIST Standard Reference Material (SRM) 2461/2461 Standard Bullets and Casings, and received high measurement reproducibility. It is suggested that the proposed parameter and algorithm can be generally used for measurement and comparison of 2D and 3D surface topographies in surface metrology and other areas.
The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alc... more The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 Bullets and 2461 Casings. NIST has also developed a 2D and 3D Topography Measurement and Correlation System for ballistics signature measurements. This system includes stylus instruments and a confocal microscope for 2D and 3D topography measurements, and a 2D and 3D topography correlation program developed by NIST. NIST and ATF are proposing to establish a National Ballistics Measurement Traceability and Quality System using these materials. In this paper, basic concepts and specific requirements for establishing ballistics measurement traceability are introduced; three key issues are discussed that include: (1) establishing a reference standard; (2) establishing an unbroken chain of calibrations; and (3) evaluating measurement uncertainty for both the geometrical topography measurements and the optical image correlations of the ballistics signatures.
ABSTRACT The National Institute of Standards and Technology is developing reference standards thr... more ABSTRACT The National Institute of Standards and Technology is developing reference standards through its Office of Law Enforcement Standards with funding provided by the National Institute of Justice. The standard reference materials are used by crime laboratories to verify that results obtained when using their protocols and methodologies meet legal requirements and that equipment is operating properly. The NIST Reference Materials 8240/8250 standard bullets and casings is an example of materials that will assist laboratories in calibrating their instruments and ensuring quality control.The Office of Law Enforcement Standards (OLES) at the National Institute of Standards and Technology (NIST) manages research in many different disciplines of forensic science. One of these projects supports the National Integrated Ballistics Information Network (NIBIN). NIST digitized six bullet signatures from samples provided by the Bureau of Alcohol, Tobacco, and Firearms (ATF) and the Federal Bureau of Investigation (FBI). Using these signatures as a virtual standard, NIST’s Instrument Shop manufactured 20 reference materials (RM) 8240 standard bullets using a numerically-controlled diamond turning machine. Test results show high reproducibility of the bullet signatures on standard bullets. NIST has also developed a new parameter for bullet signature comparisons, using autocorrelation functions, and proposed a diagram for tracing local ballistics measurements to the National Laboratory Center of the ATF and to the FBI. Using an electro-forming process, NIST has manufactured prototype standard casings and test results show high reproducibility for the casing signatures.
Light scattering belongs to a class of techniques known as areaintegrating methods for measuring ... more Light scattering belongs to a class of techniques known as areaintegrating methods for measuring surface texture. Rather than relying on coordinate measurements of surface points, these methods probe an area of the surface altogether and yield parameters that are characteristic of the texture of the area as a whole. The specular beam intensity, the angle resolved scatter, and the angle integrated scatter are examples of measurands from light scattering that can yield useful parameters of the surface texture. Uses of light scatter for inspecting the surfaces of mechanical and optical components as well as surfaces produced in semiconductor manufacturing are primarily reviewed here. Several documentary standards describing best practices are also briefly reviewed.
In response to the guidelines issued by the American Society of Crime Laboratory Directors/Labora... more In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, a NIST/ATF joint project entitled National Ballistics Imaging Comparison (NBIC) was initialized in 2008. The NBIC project aims to establish a National Traceability and Quality System for ballistics identifications in crime laboratories within the National Integrated Ballistics Information Network (NIBIN) of the U.S. NIST Standard Reference Material (SRM) 2460 Bullets and 2461 Cartridge Cases are used as reference standards. 19 ballistics examiners from 13 U.S. crime laboratories participated in this project. They each performed 24 periodic image acquisitions and correlations of the SRM bullets and cartridge cases over the course of a year, but one examiner only participated in Phase 1 tests of SRM cartridge case. The correlation scores were collected by NIST for statistical analyses, from which control charts and control limits were developed for the proposed Quality System and for promoting future assessments and accreditations for firearm evidence in U.S. forensic laboratories in accordance with the ISO 17025 Standard.
Three optical instruments including an interferometric microscope, a Nipkow disc confocal microsc... more Three optical instruments including an interferometric microscope, a Nipkow disc confocal microscope and a laser scanning confocal microscope and a stylus instrument are used for the measurements of bullet profile signatures of a National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 2460 standard bullet. The two-dimensional profile signatures are compared with the virtual bullet standard signature established by the same stylus instrument. The bullet signature differences are quantified by the maximum cross-correlation function CCF max. If the compared signatures were exactly the same, CCF max would be 100%. Comparison results show close agreement among the four techniques for bullet profile signature measurements. The average CCF max values are higher than 90%. This supports the possibility of using surface topography techniques for ballistic identifications as an alternative to the current technology based on image comparisons.
A bullet signature measurement system based on a stylus instrument was developed at the National ... more A bullet signature measurement system based on a stylus instrument was developed at the National Institute of Standards and Technology (NIST) for the signature measurements of NIST RM (Reference Material) 8240 standard bullets. The standard bullets are developed as a reference standard for bullet signature measurements and are aimed to support the recently established National Integrated Ballistics Information Network (NIBIN) by the Bureau of Alcohol, Tobacco and Firearms (ATF) and the Federal Bureau of Investigation (FBI). The RM bullets are designed as both a virtual and a physical bullet signature standard. The virtual standard is a set of six digitized bullet signatures originally profiled from six master bullets fired at ATF and FBI using six different guns. By using the virtual signature standard to control the tool path on a numerically controlled diamond turning machine at NIST, 40 RM bullets were produced. In this paper, a comparison parameter and an algorithm using autoand cross-correlation functions are described for qualifying the bullet signature differences between the RM bullets and the virtual bullet signature standard. When two compared signatures are exactly the same (point by point), their cross-correlation function (CCF) value will be equal to 100%. The measurement system setup, measurement program, and initial measurement results are discussed. Initial measurement results for the 40 standard bullets, each measured at six land impressions, show that the CCF values for the 240 signature measurements are higher than 95%, with most of them even higher than 99%. These results demonstrate the high reproducibility for both the manufacturing process and the measurement system for the NIST RM 8240 standard bullets.
Surface Topography: Metrology and Properties, 2015
The application of surface topography measurement methods to the field of firearm and toolmark an... more The application of surface topography measurement methods to the field of firearm and toolmark analysis is fairly new. The field has been boosted by the development of a number of competing optical methods, which has improved the speed and accuracy of surface topography acquisitions. We describe here some of these measurement methods as well as several analytical methods for assessing similarities and differences among pairs of surfaces. We also provide a few examples of research results to identify cartridge cases originating from the same firearm or tool marks produced by the same tool. Physical standards and issues of traceability are also discussed.
Silicon single atom steps as AFM height standards. [Proceedings of SPIE 4344, 157 (2001)]. Ronald... more Silicon single atom steps as AFM height standards. [Proceedings of SPIE 4344, 157 (2001)]. Ronald G. Dixson, Ndubuisi G. Orji, Joseph Fu, Vincent Tsai, Ellen D. Williams, Raghu Kacker, Theodore V. Vorburger, Hal L. Edwards, Debra Cook, Paul E. West, Ralph Nyffenegger. ...
Based on the maximum cross-correlation function, CCF max , a new parameter called signature diffe... more Based on the maximum cross-correlation function, CCF max , a new parameter called signature difference, D s , is developed for verifying the similarity of the 2D and 3D ballistics signatures of the standard bullets and of the prototype standard casings. It is suggested that the parameter and algorithm developed for the standard bullets and casings project could be used for any 2D and 3D surface topography comparisons in surface metrology. * Certain commercial equipment, instruments, or materials are identified in this paper to specify adequately the experimental procedure. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose.
The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alc... more The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 Bullets and 2461 Casings. NIST has also developed a 2D and 3D Topography Measurement and Correlation System for ballistics signature measurements. This system includes stylus instruments and a confocal microscope for 2D and 3D topography measurements, and a 2D and 3D topography correlation program developed by NIST. NIST and ATF are proposing to establish a National Ballistics Measurement Traceability and Quality System using these materials. In this paper, basic concepts and specific requirements for establishing ballistics measurement traceability are introduced; three key issues are discussed that include: (1) establishing a reference standard; (2) establishing an unbroken chain of calibrations; and (3) evaluating measurement uncertainty for both the geometrical topography measurements and the optical image correlations of the ballistics signatures.
Based on the maximum cross-correlation function, CCF max , a new parameter called signature diffe... more Based on the maximum cross-correlation function, CCF max , a new parameter called signature difference, Ds, is developed for verifying the similarity of the 2D and 3D ballistics signatures of the standard bullets and of the prototype standard casings. It is suggested that the parameter and algorithm developed for the standard bullets and casings project could be used for any
ABSTRACT The National Institute of Standards and Technology is developing reference standards thr... more ABSTRACT The National Institute of Standards and Technology is developing reference standards through its Office of Law Enforcement Standards with funding provided by the National Institute of Justice. The standard reference materials are used by crime laboratories to verify that results obtained when using their protocols and methodologies meet legal requirements and that equipment is operating properly. The NIST Reference Materials 8240/8250 standard bullets and casings is an example of materials that will assist laboratories in calibrating their instruments and ensuring quality control.The Office of Law Enforcement Standards (OLES) at the National Institute of Standards and Technology (NIST) manages research in many different disciplines of forensic science. One of these projects supports the National Integrated Ballistics Information Network (NIBIN). NIST digitized six bullet signatures from samples provided by the Bureau of Alcohol, Tobacco, and Firearms (ATF) and the Federal Bureau of Investigation (FBI). Using these signatures as a virtual standard, NIST’s Instrument Shop manufactured 20 reference materials (RM) 8240 standard bullets using a numerically-controlled diamond turning machine. Test results show high reproducibility of the bullet signatures on standard bullets. NIST has also developed a new parameter for bullet signature comparisons, using autocorrelation functions, and proposed a diagram for tracing local ballistics measurements to the National Laboratory Center of the ATF and to the FBI. Using an electro-forming process, NIST has manufactured prototype standard casings and test results show high reproducibility for the casing signatures.
This is an analysis of standards related to dimensional metrology, with recommendations regarding... more This is an analysis of standards related to dimensional metrology, with recommendations regarding standards development. The analysis focuses on the degree to which existing and developing standards provide a complete set of non-overlapping specifications for information needed to perform dimensional metrology. The analysis identifies four major software systems and their interfaces. It also identifies 15 dimensional metrology activities, each of which is expected to correspond to a software module. The major systems are made up of sets of modules. Twenty-two application programming interfaces and data formats for dimensional metrology are identified and discussed. The analysis also discusses issues regarding languages in which standards may be written.
Advanced Characterization Techniques for Optics, Semiconductors, and Nanotechnologies III, 2007
Based on the cross-correlation function (CCF), a new parameter called profile difference, Ds (or ... more Based on the cross-correlation function (CCF), a new parameter called profile difference, Ds (or topography difference for 3D), is developed for measurement and comparison of 2D profiles and 3D topographies. When Ds = 0, the two compared profiles or topographies must be exactly the same (point by point). A 2D and 3D topography measurement system was established at the National Institute of Standards and Technology (NIST), that includes data acquisition stations using stylus instruments and a confocal microscope, and a correlation program using the proposed parameter Ds and the cross-correlation function maximum CCFmax. This system has been used for 2D and 3D ballistics signature measurements of the NIST Standard Reference Material (SRM) 2461/2461 Standard Bullets and Casings, and received high measurement reproducibility. It is suggested that the proposed parameter and algorithm can be generally used for measurement and comparison of 2D and 3D surface topographies in surface metrology and other areas.
The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alc... more The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 Bullets and 2461 Casings. NIST has also developed a 2D and 3D Topography Measurement and Correlation System for ballistics signature measurements. This system includes stylus instruments and a confocal microscope for 2D and 3D topography measurements, and a 2D and 3D topography correlation program developed by NIST. NIST and ATF are proposing to establish a National Ballistics Measurement Traceability and Quality System using these materials. In this paper, basic concepts and specific requirements for establishing ballistics measurement traceability are introduced; three key issues are discussed that include: (1) establishing a reference standard; (2) establishing an unbroken chain of calibrations; and (3) evaluating measurement uncertainty for both the geometrical topography measurements and the optical image correlations of the ballistics signatures.
ABSTRACT The National Institute of Standards and Technology is developing reference standards thr... more ABSTRACT The National Institute of Standards and Technology is developing reference standards through its Office of Law Enforcement Standards with funding provided by the National Institute of Justice. The standard reference materials are used by crime laboratories to verify that results obtained when using their protocols and methodologies meet legal requirements and that equipment is operating properly. The NIST Reference Materials 8240/8250 standard bullets and casings is an example of materials that will assist laboratories in calibrating their instruments and ensuring quality control.The Office of Law Enforcement Standards (OLES) at the National Institute of Standards and Technology (NIST) manages research in many different disciplines of forensic science. One of these projects supports the National Integrated Ballistics Information Network (NIBIN). NIST digitized six bullet signatures from samples provided by the Bureau of Alcohol, Tobacco, and Firearms (ATF) and the Federal Bureau of Investigation (FBI). Using these signatures as a virtual standard, NIST’s Instrument Shop manufactured 20 reference materials (RM) 8240 standard bullets using a numerically-controlled diamond turning machine. Test results show high reproducibility of the bullet signatures on standard bullets. NIST has also developed a new parameter for bullet signature comparisons, using autocorrelation functions, and proposed a diagram for tracing local ballistics measurements to the National Laboratory Center of the ATF and to the FBI. Using an electro-forming process, NIST has manufactured prototype standard casings and test results show high reproducibility for the casing signatures.
Light scattering belongs to a class of techniques known as areaintegrating methods for measuring ... more Light scattering belongs to a class of techniques known as areaintegrating methods for measuring surface texture. Rather than relying on coordinate measurements of surface points, these methods probe an area of the surface altogether and yield parameters that are characteristic of the texture of the area as a whole. The specular beam intensity, the angle resolved scatter, and the angle integrated scatter are examples of measurands from light scattering that can yield useful parameters of the surface texture. Uses of light scatter for inspecting the surfaces of mechanical and optical components as well as surfaces produced in semiconductor manufacturing are primarily reviewed here. Several documentary standards describing best practices are also briefly reviewed.
In response to the guidelines issued by the American Society of Crime Laboratory Directors/Labora... more In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, a NIST/ATF joint project entitled National Ballistics Imaging Comparison (NBIC) was initialized in 2008. The NBIC project aims to establish a National Traceability and Quality System for ballistics identifications in crime laboratories within the National Integrated Ballistics Information Network (NIBIN) of the U.S. NIST Standard Reference Material (SRM) 2460 Bullets and 2461 Cartridge Cases are used as reference standards. 19 ballistics examiners from 13 U.S. crime laboratories participated in this project. They each performed 24 periodic image acquisitions and correlations of the SRM bullets and cartridge cases over the course of a year, but one examiner only participated in Phase 1 tests of SRM cartridge case. The correlation scores were collected by NIST for statistical analyses, from which control charts and control limits were developed for the proposed Quality System and for promoting future assessments and accreditations for firearm evidence in U.S. forensic laboratories in accordance with the ISO 17025 Standard.
Three optical instruments including an interferometric microscope, a Nipkow disc confocal microsc... more Three optical instruments including an interferometric microscope, a Nipkow disc confocal microscope and a laser scanning confocal microscope and a stylus instrument are used for the measurements of bullet profile signatures of a National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 2460 standard bullet. The two-dimensional profile signatures are compared with the virtual bullet standard signature established by the same stylus instrument. The bullet signature differences are quantified by the maximum cross-correlation function CCF max. If the compared signatures were exactly the same, CCF max would be 100%. Comparison results show close agreement among the four techniques for bullet profile signature measurements. The average CCF max values are higher than 90%. This supports the possibility of using surface topography techniques for ballistic identifications as an alternative to the current technology based on image comparisons.
A bullet signature measurement system based on a stylus instrument was developed at the National ... more A bullet signature measurement system based on a stylus instrument was developed at the National Institute of Standards and Technology (NIST) for the signature measurements of NIST RM (Reference Material) 8240 standard bullets. The standard bullets are developed as a reference standard for bullet signature measurements and are aimed to support the recently established National Integrated Ballistics Information Network (NIBIN) by the Bureau of Alcohol, Tobacco and Firearms (ATF) and the Federal Bureau of Investigation (FBI). The RM bullets are designed as both a virtual and a physical bullet signature standard. The virtual standard is a set of six digitized bullet signatures originally profiled from six master bullets fired at ATF and FBI using six different guns. By using the virtual signature standard to control the tool path on a numerically controlled diamond turning machine at NIST, 40 RM bullets were produced. In this paper, a comparison parameter and an algorithm using autoand cross-correlation functions are described for qualifying the bullet signature differences between the RM bullets and the virtual bullet signature standard. When two compared signatures are exactly the same (point by point), their cross-correlation function (CCF) value will be equal to 100%. The measurement system setup, measurement program, and initial measurement results are discussed. Initial measurement results for the 40 standard bullets, each measured at six land impressions, show that the CCF values for the 240 signature measurements are higher than 95%, with most of them even higher than 99%. These results demonstrate the high reproducibility for both the manufacturing process and the measurement system for the NIST RM 8240 standard bullets.
Surface Topography: Metrology and Properties, 2015
The application of surface topography measurement methods to the field of firearm and toolmark an... more The application of surface topography measurement methods to the field of firearm and toolmark analysis is fairly new. The field has been boosted by the development of a number of competing optical methods, which has improved the speed and accuracy of surface topography acquisitions. We describe here some of these measurement methods as well as several analytical methods for assessing similarities and differences among pairs of surfaces. We also provide a few examples of research results to identify cartridge cases originating from the same firearm or tool marks produced by the same tool. Physical standards and issues of traceability are also discussed.
Silicon single atom steps as AFM height standards. [Proceedings of SPIE 4344, 157 (2001)]. Ronald... more Silicon single atom steps as AFM height standards. [Proceedings of SPIE 4344, 157 (2001)]. Ronald G. Dixson, Ndubuisi G. Orji, Joseph Fu, Vincent Tsai, Ellen D. Williams, Raghu Kacker, Theodore V. Vorburger, Hal L. Edwards, Debra Cook, Paul E. West, Ralph Nyffenegger. ...
Based on the maximum cross-correlation function, CCF max , a new parameter called signature diffe... more Based on the maximum cross-correlation function, CCF max , a new parameter called signature difference, D s , is developed for verifying the similarity of the 2D and 3D ballistics signatures of the standard bullets and of the prototype standard casings. It is suggested that the parameter and algorithm developed for the standard bullets and casings project could be used for any 2D and 3D surface topography comparisons in surface metrology. * Certain commercial equipment, instruments, or materials are identified in this paper to specify adequately the experimental procedure. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose.
The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alc... more The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 Bullets and 2461 Casings. NIST has also developed a 2D and 3D Topography Measurement and Correlation System for ballistics signature measurements. This system includes stylus instruments and a confocal microscope for 2D and 3D topography measurements, and a 2D and 3D topography correlation program developed by NIST. NIST and ATF are proposing to establish a National Ballistics Measurement Traceability and Quality System using these materials. In this paper, basic concepts and specific requirements for establishing ballistics measurement traceability are introduced; three key issues are discussed that include: (1) establishing a reference standard; (2) establishing an unbroken chain of calibrations; and (3) evaluating measurement uncertainty for both the geometrical topography measurements and the optical image correlations of the ballistics signatures.
Based on the maximum cross-correlation function, CCF max , a new parameter called signature diffe... more Based on the maximum cross-correlation function, CCF max , a new parameter called signature difference, Ds, is developed for verifying the similarity of the 2D and 3D ballistics signatures of the standard bullets and of the prototype standard casings. It is suggested that the parameter and algorithm developed for the standard bullets and casings project could be used for any
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Papers by Ted Vorburger