The Professional Society of Forensic Mapping believes that the following are minimum standards for proper scene measuring:
Use of an EDMI with a “dual axis” compensator.
- A dual axis tilt sensor detects deviation of the standing axis from the perpendicular in both x and y directions. Correction values for horizontal and vertical circle readings are automatically computed and applied.
Use of the Reference Measurement Protocol.
- A verification method in which a “known” distance can be determined, commencing at the beginning and conclusion of scene mapping, with distances determined by a total station and recorded in an electronic data collector. This distance is then verified by use of a tape measure. (Also provides a “check” on angular readings).
Use of a “Red Aiming Dot” Measurement Protocol (if applicable)
- A verification method at the beginning of laser dot scene mapping in which a target marker is sighted with the standard aiming reticle and compared to the red laser dot. This ensures that the red laser dot is properly in line with the total station EDMI.
Saving/Preserving the original “raw” scene data file.
The raw data files from the total station should be saved, in addition to those used in making the final scene diagram. The raw data file is that first file produced by the total station and generally includes: Horizontal Angle, Vertical Angle, and Slope Distance to each point measured. It is not the x y z coordinates which are processed by software from the raw data.
Approved PSFM Instructors
- Michael J. “Mick” Capman
- Dennis Payne
- Kent E. Boots
- Joel Salinas