Maybe you want to connect with the people at Fleye. Their drone is quite close to what you have in mind. Le 7 oct. 2015 17:55, "Eliot Miranda" <[email protected]> a écrit :
> Dear Friends and Colleagues, > > as you may know, Sharks, as apex predators, are vital to maintaining > healthy marine ecosystems, and at the same time, their populations are > plummeting due to human actions. It is estimated for example that the > population of pelagic oceanic white tip sharks is reducing by 17% per year > [1] and I've heard (can't find a reference) that populations in the eastern > indian/western pacific are at 1% of normal levels. Such reductions in > populations create "trophic cascades" that produce wide-ranging changes in > populations of different species all the way down the food chain [2]. And > the marine ecosystem is a key source of human nutrition; it comprises > between 13% and 17% of global human protein intake [3]. > > As you may also know, there is currently a shark attack crisis in New > South Wales [4]. While most people in the region oppose killing sharks in > response to the crisis, existing solutions, netting and culling reduce > those same threatened populations of sharks upon which the sustainability > of marine food supply d ecosystems depend [5], and are arguably ineffective > [6]. Apparently the most successful approach at avoiding attacks is the > use of human spotters, as used in Cape Town, where people in tall towers > scan the sea close to shore [6]. > > But please watch this Youtube video > <https://www.youtube.com/watch?v=q2U3gjwJfS4> [7] from Pismo Beach, > California. The shark is spotted at about 1:20 into the video. This > drone, a phantom 3, is sending live video back to the operators, who are > using remote control. What we can see from this video is that the point of > view of drones is far superior to that of spotters. > > My first thought is that autonomous drones could provide a cheap and > scalable solution to patrolling beaches to prevent shark attacks. I expect > that processors like the Pi 2 have easily enough processing power to both > plan and execute search patterns along beaches, and perform the image > recognition necessary to reliably detect potentially dangerous sharks. A > drone might also be able autonomously to visit surfers and swimmers near to > the shark and warn them, either by some signal such as flashing red LEDs or > an audible message (language issues notwithstanding). The drone would have > to be able to identify swimmers and surfers in the water (not easy; sharks > confuse seals and surfers all the time), but computing an optimal route to > visit suspected swimmers should be relatively easy :-). > > I imagine that sooner or later it will be possible to construct cheap > rugged solar powered docking/charging shelters that drones could depart > from and return to, to charge and shelter from the elements after patrols. > Satellite communications could provide status reports for maintenance. > > My second thought is that as a community, we probably have all the > necessary expertise to construct a working prototype that at least > demonstrates feasibility. Such a prototype would have to be able to fly > above the ocean along a beach under its own control for a useful period of > time, at least 15 minutes, and demonstrate that it can identify a shark in > the water (we could use a rubber shark > <https://www.youtube.com/watch?v=9dghbyBaQyI> for testing ;-) ). > > Our community includes people doing image recognition with the Pi, radio > control experts, users of 3D printers, and some exceptional programmers. > If a small, strong group could be formed with the relevant expertise we may > be able to develop a prototype in a short enough time frame to be > relevant. Of course, availability of time is a big issue. I couldn't > contribute more than a few hours a week. But nothing ventured, nothing > gained. So I'm writing this message to the Squeak and Pharo communities, > and bcc'ing a few friends I know that have relevant expertise to ask for > two things; first, for good information on scoping out the project, > possible technologies, power budgets, costs, what is available > off-the-shelf (both in hardware and known algorithms) and what we would > need to construct ourselves, and second, for volunteers. Who among us are > really excited by this project, have relevant expertise and are motivated > to make a contribution? > > > [1] www.sharkadvocates.org/cites_4sharks_owt_fact_sheet.pdf > [2] http://www.globalshark.ca/pressmaterial/cascading/fig1_web.pdf > [3] http://www.who.int/nutrition/topics/3_foodconsumption/en/index5.html > [4] http://www.bbc.com/news/world-australia-34398516 > [5] > http://www.theguardian.com/environment/2015/sep/29/shark-hit-australian-community-opposes-cull-research-finds > [6] http://www.nonswsharkcull.net/latestnews/tag/shark_spotting/ > [7] https://www.youtube.com/watch?v=q2U3gjwJfS4 > > > > crazier ideas: > > Infra red cameras are becoming cheap and easily available. Species like > Great White and Bull Shark have elevated metabolisms, effectively they are > warm blooded, so these two facts may allow spotting at night. > > Sharks are extremely sensitive to electrical fields; maybe some kind of > transmitter could be fitted to a drone, e.g. via a wire suspended in the > water, that could generate a field that could direct the shark away from > swimmers > > _,,,^..^,,,_ > best, Eliot >
