PRSPECTIVE GRID FOR PHOTOGRAPHIC MAPPING OF EVIDENCE
Investigation of an accident or crime may require photographs and a map of the scene. Adequate photographs pose no problem since they can be taken quickly but obtaining measurements for a map is a more time consuming and tedisou task. Specially designed cameras for photographic mapping are expensive and not generally available. A simple solution is to make photographs for which maps can be drawn if and when they are needed. The principle is simple - if the subject to be mapped is on a flat floor or pavement, a perspective grid, (i.e., a rectangle of known size), can be shown on that surface in the picture. This serves the dual purpose of establishing a scale and providing reference points from which a map can be drawn. With the rectangle as a base, an application of the principles of perspective will enable a draftsman to produce an accurate map. This handbook provides simple. Yet detailed guidelines for the construction and use of the perspective grid plus procedures for drawing a map from photographs showing the grid. The many photographs and diagrams illustrating the principles involved in using perspective grids make this time saving technique easily adaptable by police investigators.
Northwestern University, EvanstonTraffic Institute, 405 Church Street
Evanston, IL USA 60208
- Baker, S J
- Publication Date: 1972
- Pagination: 11 p.
- TRT Terms: Evidence; Grids (Coordinates); Grids (Transmission lines); Mapping; Perspective views; Photographs
- Subject Areas: Highways; Law; Safety and Human Factors;
- Accession Number: 00141722
- Record Type: Publication
- Source Agency: National Criminal Justice Service
- Files: TRIS
- Created Date: Aug 4 1977 12:00AM