Detection of dead body underwater

Hi,

I am planning to do research about finding dead body under water using computer vision technics. Could you please share some introductional informations? I would like to get any suggestion regarding this topic.

Thanks.

[John BG]

'dead body'? human? animal? how many?

most of dead bodies tend to float, unless with enough ballast strapped to something heavy enough or anchored

once the temperature of the 'body' equals the temperature of the body, infra-red does not help, unless the body was frozen, but temperatures of contacting bodies tend to equal, thermodynamic basics. Since the mass of the immersed body is far smaller than the mass of the pool, temperature of the body will level down or up to the water temperature.

You have better chances

1.- Scanning the surface with visual and attempting to visually match found objects to reasonable size and shape of the bodies sought, remember, knowledge is 'a priori', not 'a posteriori' (you need to know what you are looking for before you start looking for it).

2.- scanning down to sea bed with LIDAR

http://www.asiageospatialforum.org/2011/proceeding/pps/David.pdf

The main problem is that airborne scanning platforms are not that expensive compared to the shear cost of keeping the platform 'up there', 'long enough' to catch something. It's like in telecommunications urban last mile to customers, the cost of taking a platoon down to the street and simply wiring something, let along digging a trench, or erecting, drilling supports is far more expensive than the cost of the wired network to install.

Your aircraft is going to sweep a narrow area, linearly, but a body may drift, float, sink, float again, so it may happen that you scan a section, wrongly assume that area is empty and then move to next section, and the body has drifted backwards.

The beam is really narrow, and bear in mind that the sea is not flat, there are waves that will shadow and temporarily hide areas where you are only going to have the camera a few seconds on.

Hope it helps

John

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[YILDIRAY YILMAZ]

Hi John,

Thanks for your interest and detailed answer. My aim is to find human's dead body. There are a lot of drowning in water incidents (usually in slack water) or some child disappearance cases in my town. After many of these incidents, dead human bodies can't find by divers. I thought that maybe i can develop a system to find human corpses under the water. Actually, i am planning to develop an autonomous underwater vehicle with powerful lights and high resolution stereo cameras. Thus, your second advice which is LIDAR seems very complicated and expensive system for me. I found some research about recognizing fish in the underwater videos. I expect that some kind of that approaches could apply for the human dead bodies. Your first advice is more suitable for me but as you said i have to know the information of the objects that i look for before the scanning.

Thanks, Yildiray

[prem matlani]

Hi Yildiraj,

i have to do a research for a specific case similar to yours. i have to search for sensors that can be used for an autonomous submarine to search weapons (metals) and human bodies. In my case im not allowed to use cameras or any light sensors. what could i use? thank you

Answer 1

[Walter Roberson]

I recommend that you have a look at OpenROV which designs and builds autonomous underwater vehicles and has a very large enthusiast community. The history of it is somewhat interesting: active crowd collaboration has been a part of it from nearly the very beginning of the project. It is not a typical commercial project at all.