Kind: captions
Language: en
[Music]
hi everyone and welcome back to this
series on how to do open source
investigations from home
i'm ben and this is part nine so let's
get started
[Music]
in this session i really want to share
with you my favorite
free satellite imagery resources that i
use
what i like about sharing these
resources with you is that no matter who
you are
or where you are in the world you can
access them for no cost
just like these tutorials that i'm
making here
and all you need is a computer and an
internet connection to access them
so let's get started with my favorite
number one
source for satellite imagery which is
google earth
and that's the desktop version not the
web-based version
for those of you that are more familiar
with using google maps
or with using google earth on the
web-based version
you'll notice there's a lot of
similarities but when you download
the google earth desktop version there
are a huge amount of
added extras that you've got this
satellite image that you're seeing right
here is of a village
in nigeria's borno state in the north
what's really interesting about google
earth is that we can scroll backwards
and forwards in time
so for example if i scroll forwards from
october 2014 to
february february 2017 you can see that
that village disappears
and we can see a lot more of those on
google earth
as we go through in different areas what
i really like
about using google earth is the fact
that
we can actually save our pins on a map
and get more of an understanding as to
trends or things like that that might
have occurred
so for example this is just a little
project that i've been working on where
i'm mapping
villages that were destroyed in
nigeria's borno state between the 2014
2017 period and the only way
we can really see them is if we scroll
back in time
on satellite imagery just like this one
that we're seeing in this location here
where this village was uh very much
present
and you can see that by the roofs you
can see that by
some of the changes that we can see in
the village and then if we scroll
through
to 2017
2018 significant change with all the
roofs destroyed or removed
and then the place has grown over and
subsequently we're just left with ruins
in that place
so this is one of the reasons why i
really like google earth
just to explain a little bit more about
the availability of past satellite
imagery
if we go to a place like london uh in
the uk
we can also see just how far back we can
go so
the uk has available imagery on google
earth
right back to 1945 as we can see here
and these are images that are taken of
london
uh from 1945 we can scroll forwards uh
1985 looks a little bit more blurry but
then we can start to go
forward a little bit more and see how
the area changes
over time and that's a huge benefit that
we have in google earth that we don't
really have in many other places
especially the fact that we can
get such clear imagery one of the other
benefits about google earth
is the fact that we can bring in
different layers as well
so for example if i wanted to bring in
google maps
uh and use their their naming system or
or their
their data and then also bring in
perhaps bing
maps in their aerial version i could do
that as well
and that gives me a entirely different
satellite image
as to what would usually be available in
google earth and that's just through
using the kml and kmz's that are
freely available on the internet so now
we move on to the second satellite
imagery source that i really enjoy using
a lot
which is sentinel hub sentinel hub just
like google earth
brings in a multiple amount of data sets
that you can select from
and you can choose to have a look at the
sentinel satellite system
landsat motor sentinel one but also some
others through the
eo browser that they have at the moment
i'm looking at sentinel hub playground
one thing to point out is that the
satellite imagery
on sentinel hub is not as clear as what
you would have on google earth
but what sentinel hub lacks in clarity
because you can see it's not very clear
it makes up for in coverage and let's
have a look at what i mean by that
so if we have a look on google earth
sure things are pretty clear here we can
see the streets quite well we can see
very much the fine definition in the
buildings
when we scroll back in time and we use
that historical slider
you'll notice that it jumps almost
months so
for you can see that it's almost jumping
every two months or every
three months when i scroll back over
london with google earth imagery
in other areas that's much more worse
where it'll skip years
not just months on sentinel hub on the
other hand
you can see that i'm currently viewing
but let's jump ahead to july 2021
and you can see just how much coverage
there is for july already
so almost every three days there's a
satellite image
for july of course each time there's a
shot
sometimes there might be clouds and if
we keep going back we can find
a nice cloud-free shot just like we have
on the 31st of may here so you can see
that
there are a there is a lot more
uh satellite imagery available on
sentinel hub than there is on google
earth but it's just not as clear
this is also quite useful as a tool
because we can manipulate what we can
see
to bring out different sorts of things
in satellite imagery
for example if we wanted to look at
banding on the satellite image to have a
look at the
infrared so the vegetation filter
sentinel hub really allows us to do that
without doing any manual coding
or manual gis work which is a little bit
more difficult than the click of a
button
we can go to false color urban we can go
agriculture
i always like to use the color infrared
because when there's a fire or burnt
area
it's indicated much more easily or
much more visible than just the natural
color of the satellite imagery
one of the other cool things about
sentinel hub is that allows you to
easily apply different custom scripts to
satellite imagery as well
so for example if we wanted to see when
the fires were burning in australia
and apply a fire filter over that to see
just how big those fires actually were
when they were burning
we can use sentinel hub to really get a
good visualization of that
if you like to have a look at different
images of wildfires or things like that
then this is
quite useful for you there's also a lot
of research as to
how fires actually spread their impact
where they burn and things like that as
well
and satellite imagery can be quite
useful for that especially when you've
got an added filter that shows where the
current burning is and a satellite image
just like this
so that's the power of sentinel hub
which is much more useful
than the sporadic imagery on google
earth
just because of the coverage and the
fact that there's so many
uh different ways to process that
imagery as well
you can also create a time lapse because
there is so many images
and i've created another youtube video
which i'll link to in the description
below
on that one but now let's move on to the
third
source of satellite imagery that i've
been using a lot recently
which is zoom earth as you can see i'm
quite zoomed out at the moment and
there's a lot of details that we can
see uh so you can see something that
might look more like
a um like a weather map so we can even
see
uh nighttime effects we've got a couple
of filters on here of where the rain is
where
certain storms might be showers clouds
things like that
any dust clouds that might be coming
over and we can also
even play a time lapse of that as well
so here i'm just creating an animation
to scroll through on a basis to see the
cloud movements and to see
what's been happening to this side of
west africa
as it moves along it's also really nice
to zoom in
and have a look at the alternative
details in zoom earth that we might not
be able to see in google earth
so for example let's go to a location in
afghanistan
on google earth even if we try and
scroll back in time
the imagery of this area is
very blurry and that's because
afghanistan as a wider area
similar to iraq has quite
blurry or graded imagery however
if we go to the same location on zoom
earth which brings in satellite imagery
from microsoft
we can see that same location in so much
more detail
than what we can see on google earth
which is quite useful if you're doing
work in locations where
images might be blurry or they might not
be as
available and this really helps if
you're trying to geolocate specific
videos
so for example uh this video of an
airstrike from
the ministry of defense in afghanistan
and we can see the smoke cloud climate
come up through there and we can also
see the
the the buildings here and those
buildings these two buildings
match the exact buildings that we have
right here whereas on google earth we
wouldn't be able to verify that footage
zoom earth is also really cool for the
fact that it has a really handy function
to detect wildfires and sources of heat
so if i click that icon on the right
over there
and i go down to say
a location like this where we can see
lots of these little
red dots these are heat indicators and
this actually draws in information from
firms so if we have a look at those
places we can get a little bit closer
and we can actually see what's going on
there
and so yes there's a heat signature
coming out of this
oil refinery there and that's why there
would be a lot of these
uh in this area so now moving on to the
fourth
source for satellite imagery that i get
a lot of use out of
which is the world imagery wayback tool
and what's really useful about this is
that i can go back in time
with some of these shots so for example
i'm having a look at 2020 now so i'll go
back to
2019. and maybe even back to
2016 and we can see that there's
different shots
for each one obviously being afghanistan
there will be
less coverage however if we try that for
different places we'll get a lot more
so one of the cooler things we can do is
do a toggle
swipe mode which will let me choose
between two images so
say one with 2020 and one with 2014
and i can slide between these and just
see the change
in satellite imagery between 2014
and 2020 which is really cool and it's
something that we cannot even do
on google earth with afghanistan
and with a lot of other regions as well
just with the
availability of the satellite imagery or
also this nice little tool
just to slide between the dates as well
so those are the four favorite tools
that i really like to use
to get access to satellite imagery for
free
i hope you enjoyed this session uh
please leave
a like and a share if you think that
this might be helpful
for anyone uh that is
interested in satellite imagery or
geospatial intelligence or
environmental research or in a newsroom
if you're a journalist
please do share it and also don't forget
to leave a comment
below on any other sources that you use
for satellite imagery perhaps
what you use satellite imagery for so
thank you very much
and i'll see you in the next session