Kind: captions
Language: en
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hi everyone
and welcome back to this series on how
to do open source investigations from
home
i'm ben and this is part eight so let's
get started
[Music]
here we have an image of boris johnson
he's the current prime minister of the
uk
we can find out quite easily where it
was taken
but how do we find out exactly when it
was taken
to do this we're going to turn boris
into a sundial
and we're going to go through the
process and detail the steps on how we
find out the time
of when this image was taken
we're going to do this in a number of
steps first
we're going to have a look at the
context of the image
and see what we can identify in the
image that might give us clues as to
where
and when it was taken number two
we're going to go further and geolocate
the image
find out exactly where it was taken and
you can probably already have a few
guesses as to where right now
number three we're going to have a look
at when it was taken
and to do that we're going to do a
shadow calculation
or turn boris into a sundial to do that
we need to look at four different
variables the height of the object
or how tall is boris the length
of his shadow so how long the shadow is
that he's casting
we'll also need to know the azimuth so
the direction of sunlight and we'll also
need to know the altitude
and we're going to replicate all of this
in sun calc which is a really handy tool
it's a free to use website and we'll be
able to identify
the exact time that photo was taken just
by using boris johnson's shadow
is this technique new no it's not it's
part of a digital investigator's toolkit
when looking at verifying footage or
images
and trying to identify when they would
have been taken one case study that we
can look at that i worked on with a team
was from bbc africa i where we
documented the
location and time of where two women
and children were executed in cameroon
this technique was also used by forensic
architecture
to look at bombings in rapha and this
technique was also used by
bellingcat in the verification and
documentation
of footage of an execution in
nagorno-karabakh
you can find links to all of these case
studies and more and also the tools and
techniques in the description below
in this example i'm not going to use
some of the
more horrific human rights footage that
was used
in those case studies but i'm going to
take a easier
and more lighter on approach for the
purposes of this tutorial
specifically we're looking at boris
johnson here or a photo of him
and we want to verify exactly when
this photo was taken so how do we do
that we mentioned the steps before
and the first step was obviously looking
at the context
so what clues can we draw out of this
image to give us some context
as to when this photo may have been
taken well if we remember back to
some of the previous episodes one of the
ways was having a look at doing an image
reverse search
so we'll go ahead and do that now i'm
pasting my
image in and we can do an image of our
search and already we have one clue
as to the next one which was to
geolocate the image
it immediately says 10 downing street
which is quite handy
so now we know that this photo was taken
at 10 downing street
and we can also see the little 10 there
we also have
larry the cat in the corner from 10
downing street for those of you
that are a fan of the 10 downing street
cat
so in having a look at the further
context of this image
we already know what location it would
have been taken so it's given us 10
downing street and that makes sense just
given what we can see
in the photo of boris johnson if we go
down a little bit more
we might be able to see other forms of
the image for example we've got one here
as well and one
here there's lots of images but none of
them
are exactly the same as we can see that
we've got the little flags
here and we also have a lot of pictures
which look like they might be school
pictures
in the windows i'll also do an image
reverse search with yandex
just to double check and remember these
are two separate
image of our search platforms yandex and
google image reverse search
so we can always have a look at the
alternative results that we get
so we've got something from voa news and
this looks exactly like our photo
what do we have down here britain's
prime minister boris johnson
talks to journalists outside 10 downing
street to mark the 75th anniversary of
ve day in london
may 8 2020. great so it's given us
a date may 8 2020 ve day
but we want to know the exact time now
this has given us a big clue
which is really helpful so now we know
what location
and what day this might have been taken
this being may 8 2020 makes a lot of
sense as well as this was during the
coronavirus period
and we can see in the window up here
and and on both sides we can see a lot
of the artwork
that might have been drawn by school
children or children at home
uh for the nhs and showing their
appreciation
of the nhs we also noticed the flags
around there
uh which would have been put there for
ve day
as well okay great so now that we have
those two variables
uh we have context this photo would have
been taken on v day
may 8 2020 at 10 downing street
now we can start to really get a lot
more narrow
in terms of exactly when this photo was
taken
so how can we do that well we have to
look at four things
we need to look at the height of boris
johnson
the length of the shadow we need to look
at the altitude of the shadow
and then we need to look at the azimuth
as well and the azimuth will be
something that we can look at in terms
of using google earth
we can have a look at the direction of
sunlight as well
which will allow us to effectively turn
boris johnson into a sundial
now for those of you a little bit lost
on these steps you can also just go back
to that tool that i mentioned
suncalc which we'll be using a lot of
and you'll see the variables that we
have on here so
you can easily just hover over on each
one of these on suncalc
and get that description okay so let's
start so
the first thing i want to do is maybe
change my contrast in this image a
little bit
now i'm using preview on a mac so i'm
just going to adjust the color of the
image i'm going to make it a little bit
dark
and up the contrast you'll notice that
when i up the contrast we can see boris
johnson's shadow
a little bit stronger and that's why i'm
doing this
okay so next step we want to look at
some measurements
the first thing that i want is a
and that's the length of the object or
the height of the object i should say
now in this case our object that's
creating the shadow is boris johnson so
i want to know how
high or how tall is boris what's his
length
we have a pretty good measurement here
boris johnson is 1.75 meters tall
i'm going to go back to my image and i'm
going to say a equals
1.75 m the next one we want
is the length so i'm going to draw
another line
and this will be for the length of the
shadow now we can see the shadow
just cuts off at this part down here
just where the step starts
so i'm going to draw that line there
and we're going to call this line b
we need to know what b is as well
how on earth do we do that well first of
all we needed to have geolocated this
image now we know it's at the front of
10 downing street
so let's go there on google maps
and i'm going to zoom in on this
location so this is obviously 10 downing
street
we can see the images there they match
what we've got with boris right here
thankfully london has google street view
so i'm going to zoom in a little bit
closer because i really want to get
granular
with the detail that we're looking for
here i want to get right up close
to see this area because this is where
boris was
so what we can see this pavement right
here where boris is
and we can see that right here what we
need to do is replicate
this exact same image
in google earth so that we can measure
the length from here to here
and get the measurement of b
so let's go to google earth i've got
10 downing street as a location in here
we can see the front archway in the door
right here that's where boris would have
been standing
so i'm going to pop a pin where boris
would have been standing
and we're going to measure that line
coming back from here one way to do this
i always like to draw
an operation box of the area that i'm
looking at
so i just did that by using a
polygon and we can stretch out
a polygon from bit to bit so i've
created a nice a pre-made a nice little
operating
area right there and we can start to
turn this
into almost like a grid that we're
looking at now the line would be coming
back
from the pin right to this
corner of the gateway right there
so that's exactly what we're after this
shadow line
now to draw a line in google earth is
quite simple
all we have to do is use this function
up here
add new path and we can easily drag that
around
so how long is that line well there's a
couple of ways to do that
either we can get info and we can have a
look at the
length of this line in meters it says
here that the shadow line is 1.46 meters
so that's quite helpful
and we can also use just for easy
reference
the ruler as well so i'll use the ruler
going from the boris pin
and i'll measure my shadow line so
we have a shadow meter of 1.5 meters
i'm going to pop that in there b equals
because this is our shadow
length remember this line b equals
1.5 meters because we have those two
variables
it helps us get a third variable
if any of you remember trigonometry
you'll remember that we have opposite
hypotenuse adjacent and these allow us
to start figuring out angles
because we have a and b we can work out
the angle
of x x will be this angle that we have
right there
this is the angle that we want to
identify
for here a way to identify that angle
is by using trigonometry calculator
like this one again the link to this
tool will be
in the description below so what we have
here
is a b and we want to get
the capital a in this case i've actually
called it
uh x so we'll just replace that with a
little x
okay so side a was 1.75 meters
side b was 1.5
and now we're going to click calculate
great angle a is 49.39 degrees
so now we have another variable x equals
49.39
so now the last variable we need is the
azimuth of the sun line so i've
pre-created another line here which is
the direction of the sunlight
now just to explain the direction of the
sunlight and the shadow
notice that when the shadow changes its
direction
and length it is always in proportion
with the direction of the sunlight as
well
so if we already know the shadow line
for our boris johnson image which goes
from his foot
right to the corner of this fence post
then we know that the sun goes
in a exact straight same straight line
from the boris pin and matching up
with this shadow line so i've created a
line here
for in yellow indicating the direction
of the sunlight
i'm going to use my ruler and measure
from
my boris pin now something that you'll
notice over here
are the degrees of the direction of
sunlight as 138.13 degrees
and that's the angle that we need
perfect so 138 138.13 degrees
i'm going to put that in my image over
here
so we have all these variables in place
now let's use suncalc
the first and most important thing with
suncalc is to get your
geolocation correct in order to do that
i've already placed my pin down where
boris would have been standing so i'm
going to right click on him
i'm going to take these coordinates so
i'm going to just
paste the coordinates into the suncalc
url up here
in the url up here is obviously the
website
and then we have the latitude which is
51.5 degrees
and then we have the longitude which is
minus 0.12 and then we also have a
figure here
after the comma now this figure is quite
important
if we were to put number 4 we'll notice
that it zooms all the way out
if we put let's say 15
that's zoomed in a bit more and if we
put 19 which should be
full zoom with satellite on we'll zoom
in that's the zoom level or the height
level
and then this will be the date
afterwards and
we already know that our image was taken
on may 8 so we'll change it back to that
okay so first thing and this is the one
variable that we can put
in that we can change is the
height or object height now the object
height
is the height of the object causing the
shadow or casting the shadow
in this case it is the height or or how
tall boris johnson is which is 1.75
meters
so the shadow here at seven or eight
o'clock in the morning is four point two
eight meters that's definitely not like
it was here we
actually have or we measured the shadow
to be around about
1.5 meters a give or take a few
centimeters
so in looking at these three variables
that we have here
we want our shadow length to be about
1.5 meters
we want x or our altitude to be about 49
degrees and we want our azimuth to be
138 degrees
what i'm going to do is i'm going to
scroll around until we're about at
138 degrees so we'll keep an eye
on that one okay so we have to stop at
138.31
close and we have 1.48 meters
and we also have 49.39 very close
now you can see that when i make a
subtle change between
11 10 and 1107
that we get these very similar readings
we're getting 49 on the altitude
which is there we're getting 137 which
is only
2 degrees off on the azimuth and we're
getting the exact
length of our shadow as well
so the only time that this image could
have been taken on the 8th of may 2020
is just after the turn of the hour
at 11 a.m at 11 10
am we have 138 and 49 degrees
and we're almost going too far if we go
to closer to 1105
so we can safely say that this image was
taken
after 11 a.m in the morning and it was
definitely taken before
11 15. these findings actually make
a fair bit of sense if we have a look at
the context
of this photo as well we know that this
was taken on v
day and if we have a look at what
happens on v day we know that there is a
national two minutes of silence at 11
am now this wouldn't have been during
that period but it's likely that this
would have happened
after uh so if we have a look at these
variables the ones that we've
identified here we can see and taking
into context of what happens on v day
after 11 a.m
we can find and cross-reference that
information with our findings and
identify
that uh in fact we are very much close
to the mark
before 11 15 a.m at around about
1105 to 11 10 a.m
our variables match this was a little
bit of a more technical
uh look at imagery forensics which some
people
like to refer to it but again a lot of
things can be identified
just by a simple photo or a simple video
in future cases we'll have a look at
applying these sorts of methods to human
rights videos especially in locations
where we can't get
good satellite imagery or we can't get
close access to the ground
but at least we can place a video or a
photo of a specific incident
on a temporal map or a chronological map
to identify that it may have happened
around a specific
hour or around a specific half hour or
just in the beginning of the day or
after
or towards the end of the day so thank
you very much for
tuning in to this session again i really
appreciate all the likes comments and
shares that everyone has been providing
don't forget to click subscribe and
you'll find all of the links to all of
the case studies
tools and other reading material that
i've mentioned
in the description below and i'll see
you
in the next episode
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you