Thursday, July 23, 2009

SATAI Conference 2009

The Holman's Team recently attended the Southwestern Association of Technical Accident Investigators, Inc. (SATAI) conference in Glendale Arizona. Holman’s was invited to locate a rollover scene that was coordinated by the association for accident reconstruction purposes.

We were invited to demonstrated the use of three different technologies – Network GPS, Laser Scanning and a Robotic Total Station with Imaging Capabilities.

The first method of location was completed using a Topcon GRS-1. This handheld GPS receiver has a built in cell phone that can dial into a base reference network and receive corrections. By adding an external antenna (PGA-1) we were able to get centimeter accuracy for location. The GRS-1 also has a built-in camera for capturing images that are automatically attached as an attribute for the point. Topcon calls this a "Photo Note". The GRS-1 was used to locate the position of the vehicle, glass fragments and tire skids.

The second method of locating the accident scene was with the Topcon Image Station (IS). The IS allows the user to operate this robotic instrument in a number of different methods allowing one to collect data in accordance with the task at hand. The IS can be operated as a conventional total station, robotic total station (from the rod), or remotely with a PC.
The key to running the IS from a PC is the fact that the IS has WiFi capability and two cameras which allow the user to direct the instrument to the point of interest through the broadcast image. The cameras also allow the user to collect two images for each shot, one wide angle image and one close up (30X zoom).

The cameras can also capture a 360 degree panoramic of the scene. Topcon calls this a “Photo Field Book”. The panoramic images are viewed with included Topcon software, Image Master for IS.

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Image Master also allows the user to create 3d polylines, surface models, and solids which can be draped with the captured images to create a 3D model.
On top of all of this the IS is also capable of collecting dense point clouds for detailed object analysis.


All of the Topcon data, GPS and Terrestrial, located with the GRS-1 and the IS was processed in Topcon’s post processing and data management Software, Topcon Tools. Topcon Tools brings all of the data together for review in a number of different formats for review. In CAD view the user can view all of the data from a bird’s eye point of view. Arial imagery can also be incorporated to add background. All of the collected images can also be reviewed in accordance with the collected point of view. Tools also allows images collected by the Image Station to be used as a background for the points and polylines collected in the field. Tools also allows one to view the collected data in Google Earth with the images collect!

The third technology demonstrated was a Laser Scanner with Intelisum technology. This innovative technology can rapidly capture millions of points during each occupation station creating “point clouds” while simultaneously capturing high resolution images.

This unique new technology incorporates or “fuses” the high resolution imagery with the point clouds to create what Intelisum calls “Intelligent Pixels”. This allows the user to very quickly (really automatically) create a 3D model of the scene in Intelisum’s modeling softaware LD3 Modeler. Point information, measurements and analysis can then be made very easily in a virtual setting on the PC. Portions of this model can be exported to a CAD file or OBJ for use in other applications if needed.

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Thanks to all of the guys at SATAI for allowing us this opportunity to demonstarte this new and unique technology!