Why do we need terrestrial photography in forensic engineering investigation – ground level photography with hand-held cameras – when we have drone photography? Aerial photography that can capture the same images from all directions, heights and angles plus distance and close-ups. And software that can give you numerical values for these quantities?
And more software so you can plan a virtual flight over and around the accident or failure site before you even go there. (Ref. 1) Then tweak the flight based on what you find after you get your boots on the ground?
Why bother with the expense and incomplete coverage of ground photography when aerial photography can do almost all of it? (Ref. 2)
These thoughts came to mind during the most recent meeting of CATAIR in Moncton on March 13, 2020 and a talk and demonstration of drone photography by Robert Guertin of Millenium Film & Video Production, Dartmouth, NS.
The CATAIR meeting – the Canadian Association of Technical Accident Investigators and Reconstructionists – was attended by members representing the police, private sector and professional engineers who investigate accidents and failures in the built environment.
Robert described drone photography and what it could do, explained and showed how the equipment has evolved since about 2008 – when drone photography took off – and then demonstrated by flying over the parking lot outside.
My ear caught a remark by one about using drone infrared photography to spot hot spots on the ground during forest fire fighting. I thought, that’s one more use of drone photography that I can add to my list.
I learned some time ago about farmers flying drones over their crops. I can imagine crop flying as an excellent use of terrain analysis. For example, an easy way to learn what areas need irrigation rather than spending money irrigating the entire crop.
I understand drones are being used out west to actually water crops. Still another use.
The “terrain” being analysed is the top of the crop from a height of a few 10s of feet for what looks dry and what looks okay. I’m not certain if that’s what’s happening but it could.
I’ve been using drone photography during my forensic investigations for about five years now. On problems as diverse as:
- the effect of retaining wall construction on the flooding of a property,
- determining the presence of fuel oil contamination on new and old sites,
- assessing road safety,
- staging a potential traffic accident,
- collecting data for drafting a topographic plan of a forensic site,
- re-enactment of a traffic accident – a colleague did this recently.
- In a sense, I did it years ago during my investigation of the John Morris Rankin accident. But in this case from the top of a 100 foot high boom supporting the camera man – the “drone” – with a hand-held camera. I also flew the site of the re-enactment in a sea king helicopter – a large drone?
- increasing the effectiveness and reducing the cost of a conference call using a DVD of a previously drone-flown site distributed to each participant, (Ref. 3)
- the potential in the re-enactment of a nail gun accident – I got “aerial” video with my cell phone by reaching high while standing on my toes, but a drone flying 10 feet up would be better – next time, and,
- the quite unbelievable potential for determining the cause of large cracks in the wall of a recently constructed multi-story building – if only the parties had got to me.
To give terrestrial photography it’s due, considering it has served forensic engineering investigation well for decades, drone photography is restricted to light winds, dry weather and open scenes.
As long as s/he’s dressed for it including dry boots and his camera protected from the weather, the eye-level, ground photographer can plant her boots anywhere, in any kind of weather and in any tight nook and cranny and get the shot. Including underwater.
Low level drone photography does have it’s limits like terrestrial photography but it has taken off with new uses appearing all the time on the forensic engineer’s plate. Today, I would not investigate the site of a personal injury, like a slip and fall accident, or a component or catastrophic failure in the built environment, without getting aerial video from a drone.
References
- It’s here, cost effective, efficient aerial video for forensic investigations! Posted October 18, 2019
- A Bundle of Blogs: Aerial video of insurance and forensic sites taken with camera mounted on drones. Posted October 31, 2019
- Conference call on a “drone flight” reduces the cost of civil litigation. Posted May 18, 2017