pole and watching over a point of evidence, pushing a button, capturing that point and coordinates, and, thus, still potentially exposed to traffic in the roadway.
Trantham’s crash reconstruction consultancy uses three different types of total stations--Sokkia 600 Series non-reflectorless, reflectorless models, and recently purchased Sokkia robotic total stations.
Using a reflectorless total station, the operator can capture reflectorless points on the roadway, but the total station must be set up fairly close to the roadway. However, Trantham said, “You’re not going to capture points too far down because of the angle at which you’re capturing points. The farther away that angle is from the instrument, the shallower the angle will be. And this means the less confident you’ll be that you’re capturing the evidence.” So, the operator may have to move the total station several times to capture points of evidence, especially if the scene is a long one.
Operator skills still pivotal
Certainly the latest total station technology is changing the way crash scenes are now measured. But the quality of a measured scene really falls back on the skills, expertise and techniques applied by the total station’s operator. That is the opinion of Trantham, the Wisconsin reconstructionist.
Trantham said the operator needs to be comfortable with his total station, set it up at proper height, and know completely what kind of key evidence is needed to have a properly mapped scene and, utlimately, scaled diagram. It’s all a delicate balancing act.
Trantham also feels it’s not essential to try mapping every piece of evidence after first arriving at the scene. “Officers mapping a scene should realize they can capture much of the evidence on the day of the crash, then come back later, at a more convenient time, to capture roadway evidence,” Trantham said. “As long as they put down some permanent points (i.e., concrete nails), they can merge the roadway diagram and evidence diagram. That’s the key. The quicker you can secure that scene, the safer it is for motorists and officers,” Trantham added.
Robert Galvin writes on law enforcement and other topics from Oregon City, Ore.