OSAC Lexicon
The OSAC Lexicon is a compendium of forensic science terms and definitions. This terminology tool was created to help bring consistency and understanding to the way terms are used by the various forensic science. Use of the OSAC Lexicon does not replace the need to reference the original published source.
The terms and definitions in the OSAC Lexicon come from the published literature, including documentary standards and technical reports. It is continually updated with the latest work from OSAC units, as well as terms from newly published documentary standards and standards elevated to the OSAC Registry.
Gradually terms are evaluated and harmonized by the OSAC to a single term. This process results in an OSAC Preferred Term. An OSAC Preferred Term is a term, along with its definition, that has undergone review and evaluation by the FSSB Terminology Task Group and has been approved by the FSSB. The FSSB recommends that subcommittees use OSAC Preferred Terms when drafting standards.
The OSAC Lexicon should be the primary resource for terminology and used when drafting and editing forensic science standards and other OSAC work products.
A electronic device used to correct timing inconsistencies, stabilize, and synchronize video signals for optimum quality
Process by which images are recorded at less than the standard rate of frames per second (National Television System Committee (NTSC) 29.97; Phase Alternating Line (PAL) 25.00) thus extending the period of time that can be covered by the storage medium.
Process by which images are recorded at less than the standard rate of frames per second (National Television System Committee (NTSC) 29.97; Phase Alternating Line (PAL) 25.00) thus extending the period of time that can be covered by the storage medium
In video analysis, a feature of digital video recorders (DVRs) that allows the equipment to adhere to data retention policies that may be mandated in certain parts of the world which results in video data becoming inacces- sible after a certain date.
In video analysis, a feature of digital video recorders (DVRs) that allows the equipment to adhere to data retention policies that may be mandated in certain parts of the world which results in video data becoming inaccessible after a certain date
Process of relating images, audio, or other data to one another in a chronologi- cally ordered succession.
Process of relating images, audio, or other data to one another in a chronologically ordered succession
In computer forensics, a point in time with respect to system time used by a file system to annotate creation, access or modification of file system objects.
In computer forensics, a point in time with respect to system time used by a file system to annotate creation, access or modification of file system objects
the most distal end of a hair shaft.
the most distal end of a hair shaft.
The contact area of a tire tread against a flat surface when under load, also known as a contact patch.
See aspect ratio.
Organization responsible for recovering tissues from tissue donors.
Any solid biological specimen that is generally weighed for analysis (e.g., brain, liver, muscle, hair, bone, meconium).
See vaccine titer.
See vaccine titer.
A thick strip of rubber that, in some footwear designs, is placed around the front perimeter of the footwear surrounding the toe area.
The allowable range of deviation from the class resolution, symmetric around the classresolution value. For PIV single fingerprint scanners with the class resolution of 500 ppi,the tolerance is 2%. For all scanners other than PIV, the tolerance is 1%.
A measurement of an objects surface geometry. Topographic data may be one, two, or three dimensional.
1D topography data is also known as a Linear Profile. A linear profile with n points shall be represented as a function of a single coordinate where at each point along a single axis (xi) (where i=1,...,n) there is a measured height (zi). Both xi and zi are measured in standard units (e.g., micrometers). An example of a linear profile is a cross-section through a striated toolmark (e.g., bullet land area); where xi is a spatial position measured in micrometers and zi is the corresponding height of the striation profile measured in micrometers.
2D topography data is also known as a Planar Image. An n-by-m planar image I shall be represented as a function of two coordinates where at each point (xi, yj) (where i=1,...,n; j=1,...,m) there is a measured surface color or intensity denoted I(xi, yj). An example of 2D topographic data is an image taken through a comparison microscope; where each point I (xi, yj) is the RGB (red, green, blue) color value measured at the specified (xi, yj) position. The measured color or intensity is a function of the surface geometry and the environmental conditions (e.g., light position). Although reference scales may be included in the collected image, the points (xi, yj) may or may not be measured in standard units (e.g., micrometers).
3D topography data is also known as a Heightmap. An n-by-m heightmap H shall be represented asa function of two coordinates where at each point (xi, yj) (where i=1,...,n; j=1,...,m) there is ameasured surface height zi,j = H(xi, yj). All three coordinates xi, yj, and zi,j are measured in standardunits (e.g., micrometers). The surface H is a 1-to-1 representation of the actual object. An exampleof 3D topographic data is a primer surface measured using a confocal microscope; where each pointH(xi, yj) represents the surface height (in micrometers) measured at the specified (xi, yj) position. 3Ddata captured on hardware compliant with ANSI/ASB Standard 061, Firearm and Toolmarks 3DMeasurement Systems and Measurement Quality Control can be used in virtual comparisonmicroscopy.
Physical layout or logical operation of a network
A fire scene where a fire continued to burn until most combustibles were consumed and the fire self-extinguished due to a lack of fuel or was extinguished when the fuel load was reduced by burning and there was sufficient suppression agent application to extinguish the fire.
chromatogram created by plotting the total ion current in a series of mass spectra recorded as a function of retention time.
An individual (however named) who provides factual information and/or interpretive opinions related to the results of toxicological tests for court or investigative purposes. May be further defined by role [e.g., Toxicologist (General), Toxicologist (Alcohol), Toxicologist (Breath Alcohol)]
A minimal amount of target odor.
The property of a result of a measurement or value of a standard whereby it can be related with a stated uncertainty and to appropriate standards, generally international or national standards, through an unbroken chain of comparisons. The unbroken chain of comparisons is called a traceability chain. Traceability of a chemical species is frequently of equal or greater importance than the traceability of the calibration of the instruments used in the analysis.
Property of a result of a measurement or value of a standard whereby it can be related with a stated uncertainty, to stated references, usually national or international standards through an unbroken chain of comparisons
A sample acquired or prepared with documented origin that has known properties for the purpose of calibrating equipment and/or for use as a control.
A means of distinguishing one rope from another or one manufacturer from another by the use of yarns, tapes or other markers in a rope, either externally, internally or both. Also referred to as a marker.
A means of distinguishing one rope from another or one manufacturer from another by the use of yarns, tapes or other markers in a rope, either externally, internally or both Also referred to as a marker
A path associated with a single read/write head on a data medium.
The distance between the center points of the tires from one side of the vehicle to the other (e.g. from the center point of the right front tire to the center point of the left front tire). On a dual axle vehicle, this is the distance from the center points between the dual tires from one side of the vehicle to the other.
The scent pathway left by an individual moving.
The scent pathway left by an individual moving.
The scent pathway left by an individual moving.
The scent pathway left by an individual moving.
The propensity or learned ability of a canine to methodically follow odor/scent on the ground (human/ground disturbance) by working the canine close to the pathway. Canines are not typically pre-scented on an object.
The propensity or learned ability of a canine to methodically follow odor/scent on the ground (human/ground disturbance) by working the canine close to the pathway. Canines are not typically pre-scented on an object.
The format of transactions used in all versions of this standard prior to, and including thatof 2007. It is also included in this standard and is specified in Annex B: Traditionalencoding.
In image analysis,a technique that has a direct counterpart in traditional dark- room photography.
In image analysis, a technique that has a direct counterpart in traditional darkroom photography
Solid or liquid fuel used to intentionally spread or accelerate the spread of a fire from one area to another.
The propensity or learned ability of a canine to methodically follow the target scent. The canine may follow a scent plume which could be either air borne or settled on the ground/vegetation. The canine will use whichever technique will get them to the target the most efficiently. Canines are typically pre-scented on an object.
The propensity or learned ability of a canine to methodically follow the target scent. The canine may follow a scent plume which could be either air borne or settled on the ground/vegetation. The canine will use whichever techniqu
The propensity or learned ability of a canine to methodically follow the target scent. The canine may follow a scent plume which could be either air borne or settled on the ground/vegetation. The canine will use whichever techniqu
The potential ability and the motivation on the part of the canine to learn and develop all the skills required, and the ability to learn from successes and failures.
Any member of a specific discipline who is in a situation of instructing any part of the canine team using established methods and validated training guidelines.