Traffic Accident Reconstruction

Quickly and efficiently provide police accident reconstruction for a fatal traffic accident.  Use high resolution aerial photography to provide an untouched overhead view of the entire accident scene.

Mission Description

In the event of a serious traffic accident, police are looking to recreate and record the details of the accident as quickly and accurately as possible.  Many of the important details to reconstruct the accident are found in the area leading up to the actual scene of the accident versus simply at the scene itself.  What caused the accident?  Were there extenuating circumstances that motivated the driver’s behaviour?  Accident reconstruction experts are given the difficult task of answering these questions, while also clearing the road as quickly as possible.

Sometimes the clues that best explain the accident are not easily visible from the ground.   One significant challenge is to garner an overhead view of the entire accident scene – starting from the point where driver behaviour, such as a missed sign or an illegal lane change, needs to be recorded.  The relevant area that needs to be reconstructed could span hundreds of metres, providing a significant challenge to accident reconstruction experts.

Use Details

In this particular case, police were responding to a fatal accident on a busy city street.  On a frigid -18C day, police were required to recreate the incident which spanned over 100 metres and re-open the roadway as quickly as possible.

Using the Aeryon Scout, one of the first steps in the accident reconstruction, prior to disturbing the scene, was to take a series of overhead photographs that spanned the entire accident scene.  Taking this approach, the entire accident scene is completely recorded exactly as it was found by the accident reconstruction experts.

Within minutes of arrival, the Aeryon Scout was deployed by a single operator.  Using the Scout’s map-based interface the operator climbed to the desired altitude to get a reasonable overhead view of the accident, pointed along the stretch of road both where the accident occurred as well as immediately preceding the accident.  A series of 22 aerial photographs were taken in total, with a total flight time of less than 8 minutes.

Using off-the-shelf photograph stitching software, a complete aerial view was created of the accident scene.   The result is a 70 Megapixel image with a resolution of approximately 5 mm per pixel.  Using ground reference points, dimensions from the image can be calibrated and used for forensic measurement purposes and overall scene description.  Images from the Scout are Geo-tagged, enabling them to be imported into GIS mapping software easily.  Additionally, each image is stamped with time and date data for evidentiary purposes.

Mission Complexities

• Operation being performed in -18C weather
• City street is surrounded by obstacles such as hydro wires and buildings.
• Photographs required geo-tags for future identification purposes
• Emergency call - no pre-mission flight planning was possible
• One single operator needed to control the UAV, control the camera and monitor the surrounding area for obstacles.
• Accident blocking major roadway, required quick operation to resume traffic flow.

Mission Results

Using the Aeryon Scout and off-the-shelf photo-stitching software, a 70 Megapixel recreation of the entire accident scene was conducted in less than 10 minutes of on-scene time, with a resolution of 5 mm/pixel.  With this technique, images of limitless resolution are possible.