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.

• Corporate Authors:

  Northwestern University, Evanston

  Traffic Institute, 405 Church Street
  Evanston, IL  United States  60208
• Authors:
  • Baker, S J
• Publication Date: 1972

Media Info

• Pagination: 11 p.

Subject/Index Terms

• TRT Terms: Evidence; Grids (Coordinates); Grids (Transmission lines); Mapping; Perspective views; Photographs
• Subject Areas: Highways; Law; Safety and Human Factors;

Filing Info

• Accession Number: 00141722
• Record Type: Publication
• Source Agency: National Criminal Justice Service
• Files: TRIS
• Created Date: Aug 4 1977 12:00AM