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Language: en
hi everyone and welcome back to this
series on how to do open- Source
investigations from home I'm Ben and
this is part 22 so let's get
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started in today's session we're going
to delve a little bit deeper into the
Practical utilization of tools like
Google Earth and Sentinel Hub to
calculate the size of specific areas
using satellite imagery
alone these are essential tools that can
help you and Aid investigations and
research by providing this detailed
geographical data what I've tried to do
is to break these tools down by using
three specific case studies so we'll go
through and calculate for example the
size of an area left behind by a
wildfire so that that burn damage we'll
go through and have a look at change in
infrastructure and the area impacted by
that and we'll also go through and look
at measuring the length of an airport
the length of a Runway or the size or
area of a car park as well all of the
case studies will be included in the
description below as well as the tools
so if you want to actually follow along
and pause the video and try out some of
these yourself while you're actually
watching the video you can simply open
the links and follow through so let's
get started with the first one which is
using Google Earth Pro which is the
desktop version so there's a link below
in the description on where you can
download that from and it's a really
useful tool for measuring area of
satellite imagery measuring length of
specific objects or planes or ships or
runways but also using that on past
satellite imagery as well and we're
going to look at an example that we have
here on the screen from Mandalay in
myamar where there's been a huge amount
of homes and communities and buildings
that have been destroyed in the east of
that that city of Mandalay what you can
see on the screen here are lots of
little empty blocks and empty homes if I
click on the historical imagery you can
see what used to be there in April
2022 and then if I go forward to April
17 2023 it's no longer there and there's
hundreds of homes that have essentially
been cleared out from there so what we
want to do with this is to make an
original finding by identifying the size
of the area where the where the
destruction has occurred and this could
be helpful if you're doing a research
piece if you're doing an investigation
or if you're working on say a news
report or a feature investigation for
Google Earth Pro when you want to
measure a specific
area there's a little icon appropriately
shaped like a ruler called show ruler I
started with the tool of Google Earth
Pro because I feel like it's the most
comprehensive for measurement and you
have multiple options like line path
polygon Circle 3D path or 3D polygon as
well I'm going to start with the line
path which is just something quick to
show you and it allows you to measure in
meters or degrees inches feet
kilometers um nautical miles if you want
or or many others so I could perhaps
measure the size of this side of the
block here this road which is about
301 M if I wanted to to round it up to
the nearest one but what we want to do
is actually measure this entire block
area and I'm going to do that by
creating a polygon so I'm going to
orientate my
map a little bit easier so I can simply
create that polygon and this allows me
to start really clicking in certain
areas and I can also zoom in to make
sure that I'm actually getting the
appropriate section of the polygon where
that destruction has occurred as well so
if I want to go around some houses like
that and you can see the benefit of
creating something like a polygon is
that it allows you to be so accurate
about your corners of where you're
actually measuring this so after
selecting the area of my polygon you can
see the options that I have here so I've
got a perimeter that I can view so the
perimeter which is the line around the
outside or or that that kind of Border
area with all those connected points is
7.94 KM almost 8 km but my interest is
the area um and I could even do that in
kind of in square meters or I could do
that in square kilom and so for this
specific area now I'm able to say after
viewing this that the area that had the
most destruction was around about 1.77
or 1 .8 Square km and that's really
useful because if we're trying to add
more value to our research and be more
precise with our findings it really
helps us answer that question when we're
looking about what actually happened or
what are we seeing on this satellite
image here great so that's covering
Google Earth in the next example we're
actually going to look at Russia's
Siberia area and specifically some of
the fires that were happening there in
early
2023 around may this is a platform
called Sentinel Hub EO browser Sentinel
Hub is a satellite imagery platform that
allows you to view NASA satellite
imagery Sentinel satellite imagery and
others as well the reason why I always
like to use Sentinal Hub as a satellite
tool is because of the regularity of
coverage of it so it updates about every
3 to 5 days for example for this region
I have imagery from the 1 the 3 the
fifth the sixth uh in in around this
area so it really helps for me to view
for example fires or infrastructure
change or other patterns that I might be
looking at for my research or
investigations this specific image is
from May 8th 2023 and you can see that
date up there one of the drawbacks of
Sentinel Hub is that you're not really
using clear satellite imagery like what
you would have seen on that previous
Google Earth example where we can really
Zoom quite detailed
in so if I zoom quite closely into some
of these images you can see it is a
little bit blurry however it makes up
for that in the frequency of the image
as well and this is also really helpful
if you're observing large changes like
fire
with smoke plumes or other things like
that and so for example this image
caught on May 8
2023 we can even see some of that fire
line burning along there where there's
been where where there is that large or
significantly large fire creating that
smoke plume over some of the communities
that are there more east of where this
fire is as well which is quite
interesting before I get into the
measurement the other quick interesting
thing and you may have noticed this as
well is the banding colors over here and
this allows me to change or to filter
the satellite image like you would an
Instagram image with filters except this
one brings out different characteristics
for example I can use false color which
shows up the burn marks really well I
can use
ndvi I could have a look for moisture
index which as you can see really
highlights areas of
water uh I can do false color which is
specifically for urban but you can see
it also has a bit of banding to bring
out fires and there's many different
options for banding as well as custom
coding options for now I'm going to
stick with true color just to stick with
the normal VI version of what we usually
View and I'm going to measure this area
so on our screen it doesn't really
appear that big but if you think about
theze size of the potential of this area
it's actually quite large to measure an
area on Sentinel Hub we have the panel
on the right over here and again apply
provided we have a ruler measuring tool
this allows me to click on points on the
screen and similar to what we just did
on Google Earth before it allows me to
draw an area box to see the kind of size
of that scorched area on that day now
don't forget this is a a specific
satellite image so I'd want to make sure
that I state that this is what is
visible in the image on that day it
might be the case that this fire might
increase by five or 10 times the size we
don't know yet but we can say in this
image that we are able to at least for
this specific fire because there's many
others around it as you can see but for
this specific fire the burn bur area is
km that's
massive and we wouldn't have known that
had we not have actually been able to ma
uh measure that area or measure the the
the area size of that you can also do
straight lines with that so when you do
more than two points you'll get an area
if you only do two points it allows you
to measure a certain line so say we can
me this line and that's 6.29 or 6.3 km
so also really useful if you've
identified new areas new buildings or
new runways or the S or the length of a
ship or the width of an airplane for
example uh and then you can also do the
area as well like that in the third and
last example I'm going to take you back
to Google Earth now but I'm actually
going to take you to the Google Earth
website version it's available on your
mobile phones or your browsers without
actually having to download anything and
this is a really cool version of Google
Earth that's very simple to use and very
userfriendly less detailed than the
downloadable version but still has quite
a lot of different
functions in this specific one we're
going to use this to actually measure
first of all the length of the runway
and then second of all one of these
quite sizable car Parks over here for
this Runway we can easily measure the
tool by again the ruler icon we can
measure that in a straight line quite
easily so we'll go from here to here
this gives us a reading in meters of
almost 3,600 M we can actually change
that to kilm so the runway that we have
here is about 3.6 km great so we've done
that one and we can actually keep that
on there and save it to a project that
next time we log in we can keep that
area I'm going to remove that one and
I'm actually going to have a look at a
specific car part so say I want to have
a look
at this Row in the car park here and I
want to measure that exact one where
that paintwork is for the borders of
this specific parking area so I'm going
to measure all the way around that and
that's given me an area of
72 square m with a perimeter
of15 km or or 148 M and that's how we
actually use the measuring tool to to
measure
that great so we've covered Google Earth
Pro the downloadable version where we
measured the full area of a destroyed
portion of homes in in the Eastern side
of myanmar's manderlay we had to look at
the size of damage left behind by
wildfires in Russia using Sentinel Hub
and we also had a look at using Google
Earth on the desktop which is also
available on your phone as an
application to measure both the length
of a Runway as well as the area and size
of a car park I hope you found this
tutorial really useful and please let me
know if you have any other measuring
tools in the comments section below or
or if you able to use it on a research
piece Maybe please give us some ideas in
the comments section below as you might
Inspire another researcher or
investigator to use this tool in a
creative way thanks so much for watching
this session and I'll see you in the
next
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