
Fleets of drones could aid searches for lost hikers - chablent
http://news.mit.edu/2018/fleets-drones-help-searches-lost-hikers-1102
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bicubic
The tech required for search and rescue is the same tech required for search
and destroy.

We seem to be running headfirst into the autonomous killer bot future without
giving so much as a second look at the implications.

Slaughterbots [0] is a pretty good look at what can be achieved by refining
and integrating technologies which all exist today.

[0]
[https://www.youtube.com/watch?v=9CO6M2HsoIA](https://www.youtube.com/watch?v=9CO6M2HsoIA)

~~~
jbob2000
You can attach weapons and AI to anything, it’s not a reason to stop progress.

Morality has kept nuclear weapons in check (so far anyways), I’m sure it will
keep AI drones in check too.

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nordsieck
> Morality has kept nuclear weapons in check (so far anyways)

Morality and logistics. The major nuclear powers have implemented a relatively
successful program to make it very difficult for a non-nuclear power to
develop nuclear weapons.

> I’m sure it will keep AI drones in check too.

There is simply no way to use logistics to curtail AI drones in the same
manner as nuclear weapons; all that is needed to make a drone is a 3d printer,
common industrial components and software.

~~~
njarboe
Fortunately for an AI drone swarm to be as destructive as a decent sized nuke,
you would need millions of them. Unfortunately an AI drone swarm can be less
destructive than a nuke. It could kill all the people in a city but leave
infrastructure completely intact for the attackers to use. This future is not
here yet but is coming and it is good people are starting to talk about it.

~~~
LinuxBender
Do you need that size of destruction to keep people from leaving their homes?
Or just the fear that rogue autonomous drones are flying around with a .22 mag
attached? Wouldn't there be some economic impact from such a scenario?

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njarboe
Maybe for some small period of time, but not for long. Americans, and I think
people in general, can be quite adaptive. In Texas enough people would just
start carrying around shotguns for the chance to be the one to shoot it out of
the sky. In San Francisco, who knows, maybe some counter drone tech would be
quickly developed. A large society can absorb hundreds of deaths a day without
too many problems if it knows the problem is not going to escalate
exponentially.

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LinuxBender
Perhaps you are right. Texas certainly would adapt rather quick.

That said, some cities are already so messed up, that cops won't respond to
911 calls in some areas. I would expect that to get worse should there ever be
"thugs with drones".

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nateberkopec
The video assumes that the most important and most difficult part of a SAR
drone's job - object detection - will simply be solved at some point in the
future.

I am a SAR volunteer, and our team has used drones on real searches. What I
can tell you is that the problem is not navigation (even through forested
areas), but object detection. Even for a human being, detecting humans
(responsive or unresponsive) or _signs of human presence_ (trash, abandoned
camps, etc) from drone camera footage is extremely difficult.

Autonomous flying drone navigation is hard but identifying signs of human
presence from onboard sensor information will be much, much harder.

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BurningFrog
My takeaway is that if I'm ever lost in the wild I need to make something
VISIBLE.

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rstuart4133
There is a contest run in Australia called the "UAV Outback rescue"
[https://uavchallenge.org/](https://uavchallenge.org/) It's run by Australia's
peak scientific body, the CSIRO so the results are pretty rigorous.

The scenario is Joe is lost and incapacitated in the Australian bush. "Joe" is
a human sized dummy with a (very) small infra red source under his clothing.
He needs to be found and then have something done. He is located within an
area of about 50 sq km.

The requirement has always been the aircraft must be totally autonomous from
take-off through to landing - and that includes finding Joe. In the previous
challenge, once Joe was fond the aircraft had to land beside him, and take off
again - in an area it had never seen before.

About 6 years ago Andrew Tridgell (original author of Samba and Rsync) joined
Canberra UAV (an amateur group of UAV enthusiasts), and started working on the
Ardupilot AUV software Canberra UAV used in future attempts at the
competition. At the time nobody had completed the challenge. After Andrew
joined Canberra UAV, Canberra UAV completed the challenge every time (and
indeed until 2018 was the only team to complete it) forcing the CSIRO to up
the difficulty for the next competition to be held.

The location algorithm has been pretty simple in all cases - this is a group
of amateurs who could not use expensive LIDAR's. From memory it's multi pass.
The first pass happens from relatively high, and then promising signatures
(which are barely more than a pixel) and then investigated more closely.

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Someone1234
On a related note, sea search & rescue still primarily relies on spotters
looking out the windows trying to see something.

Seems like a place where pattern recognition could be an asset, even if it
just supplements rather than replaces a spotter. Or heck, send a Google Maps-
style image to land, and let volunteers flag points of interest.

~~~
jcrawfordor
There's a couple of different services that are taking a "Mechanical Turk"
approach to this problem right now. Probably the largest is Tomnod, which has
had volunteers classify objects in satellite images for both SAR and
humanitarian tasks: [https://www.tomnod.com/](https://www.tomnod.com/)

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lwansbrough
Lots of drone people, so I’ll drop my off topic drone question: why isn’t
gasoline more popular in the drone world? Isn’t the energy to weight ratio
like 100x compared to LiPo?

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snovv_crash
1) noisy, messy, complicated and less reliable (no redundancy)

2) minimum size before it becomes a viable strategy

3) vibrations affect any cameras, requiring extra damping

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chrisfosterelli
I don't follow why the drones _need_ to go below the canopy at all. Just use
an infrared camera! This is already being done in our local area for SAR,
though with remote controlled drones rather than autonomous[0], and it's
worked. I also worked on a undergrad research project involving autonomously
deployed drones that identified cattle with infrared and the results were a
no-brainer compared to conventional cameras[1], even though this was quite a
few years ago and both autonomous navigation and infrared options have gotten
much much better since then.

There's the problem of false positives for sure (e.g. deer), but it gives you
more than enough starting points.

This research sounds genuinely really fascinating, and I think they are making
huge progress on a difficult problem (specifically, navigating unknown 3D
space). I'm just not sure that _this_ use case is the most important one.

[0]:
[https://www.radionl.com/2018/03/11/3624/](https://www.radionl.com/2018/03/11/3624/)

[1]: [https://fosterelli.co/file/talk/tracking-cattle-with-
infrare...](https://fosterelli.co/file/talk/tracking-cattle-with-infrared-
imaging.pdf)

~~~
thaumaturgy
I'd love to hear more about cases in which IR has made a difference in a
search, because that hasn't been my experience or what I've heard about it.

And I'm calling BS on IR being able to see footprints under fresh snow, unless
that fresh snow is a light dusting about 1 cm thick -- which just about any
tracker could follow anyway.

IR requires a steep difference in thermal gradients between the subject and
the environment. In cold environments, subjects tend to wear insulating
clothing (and if they've shed that, then they've gone into the paradoxical
undressing stage of hypothermia, and unfortunately they're done for). The cold
environment also acts as a massive heat sink, quickly masking any heat
signatures.

Warm environments suffer from reflectivity. Rocks bake in the sunlight and
then re-emit that radiation all night long.

There are some environments where IR might help, but many more where it
doesn't.

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chrisfosterelli
I don't know much personally about SAR applications. But in terms of the
projects I've done, the temperature and size of the target is fairly
predictable compared to noise in the image. While it's not as easy as "filter
anything above this temperature as a positive", it's an easier engineering
program than 3D navigation.

> I'd love to hear more about cases in which IR has made a difference in a
> search, because that hasn't been my experience or what I've heard about it.

Here's another link where IR was used to find seven missing people, same trial
program: [https://bc.ctvnews.ca/a-b-c-first-heat-seeking-drone-used-
in...](https://bc.ctvnews.ca/a-b-c-first-heat-seeking-drone-used-in-search-
and-rescue-mission-1.3295797)

While looking more into this though, they mentioned that one of the things the
program found is that the drones are _not_ good at seeing through tree
canopies. This is surprising for me, and I suppose answers my question about
why this MIT project has some benefit! I stand corrected in that regard.

> There are some environments where IR might help, but many more where it
> doesn't.

Absolutely. There's no magic solution for finding people. The project here is
going to have pros and cons too, you need experienced people to know what tool
makes sense where.

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thaumaturgy
Thanks for the link.

> *...one of the things the program found is that the drones are not good at
> seeing through tree canopies. This is surprising for me...

Yeah, if you dig around a bit you can find infrared and near-infrared images
of trees and forests, and overhead IR shots of forest canopies. Trees give off
a surprising amount of IR.

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toss1
Several have commented on the likelihood that this will not be so much "Search
& Rescue" as "Search & Destroy".

It seems that the "no GPS required" spec and the under-the-canopy flying and
mapping they showed makes this considerably more likely.

Small drones on rescue missions need to find the lost person, identify their
location and transmit it back. The search/find part would be best done above
the canopy with appropriate sensors, covering as much ground as quickly as
possible. Flying under the canopy, and mapping it the whole way would
dramatically slow this process -- probably quicker to have a human horde
search on foot.

Once found, the GPS coordinates would be the most essential data point to
transmit back to the rescuers. The relative positions of all the local trees
would be kind of irrelevant, but that could be quite useful in targeting
various kinds of attack.

IOW, it seems the other Search & Destroy comments have got it right.

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chmaynard
Interesting, useful research. I didn't know that GPS is unreliable under a
forest canopy. Hmm, I wonder if hikers could aid searches for lost drones?

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dmckeon
I would think that IR sensors would be a natural choice, more for ‘lost child’
or ‘injured hiker’ than for the simpler ‘lost hiker’ scenario. One of the SAR
challenges for lost children is that they might too frightened to leap up and
wave their arms at searchers, either human or robotic. Calling a lost child by
name helps, but IR seems like a natural choice - is there a weight, battery,
or cost downside?

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thaumaturgy
Eh, the bigger problem with lost children is their habit of hiding or
wandering back into cleared areas. Fortunately, they don't tend to wander far.
Lost Person Behavior guidebook puts a 4-6 year old child at a 95% range of 5.1
miles in dry territory. That doesn't change dramatically until you start
approaching teenage ages.

I've posted a few criticisms of IR already in this thread. There are a narrow
range of environments where it's helpful, and there's a tradeoff between image
quality and flight time -- you can have good flight time and terrible image
quality, or good image quality and terrible flight time.

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hprotagonist
I will thank you very kindly to take your loud battery powered flying fire-
starters out of federal wilderness areas, thanks. SAR is hard enough as it is.

Also, and this may sound just totally perverse, when i go into a wilderness
area I really do want to be alone and out of range of the world.

~~~
lolc
Maybe you are an exception but once they're in a survival situation most
people would welcome any means to be found.

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sitkack
"Lost hikers" is really enemy combatant.

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vorpalhex
I'd imagine an enemy combatant would be using camouflage unlike a a lost hiker
who would want to be found.

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village-idiot
Hikers typically wear the exact opposite of camouflage.

Edit: really? Downvotes? Hiker gear is half neon colors and colored in
reflective tabs. Easy visibility for SAR purposes is a design criteria for
most hiking gear.

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gaius
_Hikers typically wear the exact opposite of camouflage_

Photographers, hunters and people who's taste in clothes doesn't run to the
garish?

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village-idiot
Hunter’s orange is pretty damn bright by design. I would also argue that
hunter != hiker.

I’ve never noticed a correlation between photographers and clothing colors. I
tend not to be in my own photos, so it’s not something I select gear based on.

Obviously not every bag is bright, although my wife’s bag is a nice metallic
teal, but every hiking bag I’ve ever seen has reflector tabs built in. Ditto
with our tent and rain flies, and quite a few of our tops. They help in a SAR
situation, and improve safety if you ever need to come close to a road at
night.

Taste is subjective, but outdoor gear trends towards the bright for safety
reasons.

I have _never_ seen a hiker wear camo, all of them have reflector tabs, and a
large percentage have tops, bags, and hats in bright colors. And that’s not
even getting into inclement weather gear, which trends towards the super
garish. There’s a reason why Everest has a “rainbow valley”, and it’s not
because heavy coats are designed to be subtle.

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jpindar
That sounds like a "no true Scotsman" argument.

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village-idiot
No.

I pointed out that hunting isn’t hiking (opinion, but they do have different
names), and that regardless hunters regularly wear gear that is anti-
camouflage _by design_ , making any distinction there moot.

I then proceeded to point out that hiking gear has reflective tabs and bright
colors for similar reasons. The more extreme the gear, the more intense the
visibility features on average.

I then made an observation about what I’ve seen.

At no point did I say that any of those groups aren’t “real” hikers.
Therefore, not a true Scotsman argument.

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lexxed
prometheus did this in 2012

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zython
Yeah, nah. Its only a matter of time when "find and rescue" becomes "search
and destroy".

Not to cheapen the work the authors have done, but I dont have a lot of faith
that this tech will be used for "good".

