Hi there it's Tarmo, your instructor. I'm going to provide you with a small
tutorial on downloading Sentinel data from the Copernicus open access hub. This
portal provides data for satellite Sentinel 1, 2, and 3. Today we're
going to look primarily at Sentinel 2. If you point your URL to scihub.copernicus.
eu, you should end up with a website that looks roughly like what I've got open
right now. Depending on whether or not you've been here or you're using a
public access computer or your own they may ask you to accept the use of cookies
if so you can simply click on the ok button at the top and then move on
forward feel free to look through this page to read the documents and explore a
little bit but what we're going to do is head on over here to the open hub and
click on there. This should bring up the main access for getting this data that
we're interested in now to actually access and download data we do need to
log in so if you don't have an account go down to the sign up create a free
account if you already have one and simply fill it in as I have here and
click login once we're in we're going to be able to actually download data and if
we click on this little icon at the top we can see that we are indeed logged in
and that we are allowed to not only search but also download some of the
data that we find so the first thing that we want to do is understand these
buttons here when this toggle is at the top with the four arrows we can easily
pan around on our map until we get to a location that we might be interested in
downloading data for so I'm going to head down to somewhere in Brazil here
and I'm going to zoom in we're gonna take a look at this town called Curitiba
this is where I was at a conference a little bit earlier or later in 2019 but
we're gonna then slide the slider down to the bottom it's going to allow us to
draw a box or an area of interest that's going to help us search for the data
that we are interested in for this region now we can very quickly simply
click on the little magnifying or search button and then wait while it searches
through the archive to see what's available and we can see that all of the
data sources for that area or that touch on this area are now highlighted we get
a tiny thumbnail view of what the data looks like it tells us what kind of data
product we're looking at and at the bottom we can see that we have nearly
700 pages of imagery that meet the request that we want or more precisely
here at the top o most 17,000 441 different images we may want to reduce
this set up a little bit to do that we can create a filter and if we click on
these options over here and if it's not open we can click this arrow we can come
down and say well we only want Sentinel to data by putting a checkbox in there
and we can also indicate a date where we want to start to acquire data from so
let's go let's say May 20 19 to November 20 19 somewhere let's say at the end and
then we can roll that back up click on the search again and let it refresh this
and see how many fewer images we need to actually look through depending on the
number of options depending on the period that we're setting we're going to
have more or fewer results and the processing might take a little bit
longer notice now that we have only 330 products and they're all listed as s 2
which is Sentinel 2 there are two different sentinel two
cameras a and b u tells you here which one we're looking at and the msi tells
us that we're looking at a multi sensor instrument and we can scroll down and
look at quickly these thumbnails we see that some of them have a lot of clouds
some of them are much cleaner and that there are 14 pages of imagery and we can
simply click through those things and see what it is that is available to us
of course we can zoom out to see the boundaries of the four sentinel tiles
gives us an idea of what kinds of data coverage might be available to us and as
we scroll down i'm going to just quickly look at this one it looks relatively
clear if i click on the zoom it tells shows me that it's this scene that i'm
interested in we click on the eyeball it will bring up a quick view for us we can
see that it's a nice clean looking image it shows us the extent as to where that
data set exists and then we can look under these summaries the products the
instrument information the platform information and get a real sense of what
that data looks like we can then look at all the data and so on but if this is
something that we want to download down at the bottom right hand corner we can
simply click on the download product button that will pop up an object do we
want to open it automatically with an archive utility that's usually not the
best way forward it's best to choose to save that file and then as we wait it's
going to download into whatever location our downloads go to this may take a few
seconds if you've got a fast connection it may take several minutes two hours if
you have a slow connection but I'm going to let this download and I'll be right
back when it's ready to show you what the next steps would be okay we can see
that the file has now downloaded we're going to then move that somewhere where
we can work with it I'm just going to make some room on my
desktop and I'm going to drag the file over this file is a zip file so we need
to decompress it to work with it so we can double click on it depending on the
operating system you may need to right-click and choose to decompress
but the archive utility will then go through and take all of the files out of
the archive and produce a new folder in this location with all of the structure
that is supposed to be in there as we can see from the original data set file
we no longer need this screen anymore so we can actually close it and if we're no
longer using copernicus we can actually shut that down and clean things up as we
move forward ok that process is now finished so if we have the original zip
archive and now we have the corresponding folder with the data that
was in there if we open that up to see what's in there we can see that we have
the same structure that we had for the data as we saw online all of this is
really important there's metadata in here there are different formats of the
data but we can go into this granule and down to the image data and we can see
that there's 10 20 and 60 meter spatial resolution data and we can see all the
individual bands we can use the metadata to bring this directly in to PCI we can
take a look at this in a graphic viewer these are large files because they are
high spatial resolution so things might take a little while so here we have it
this is not in a remote sensing package we don't have access to individual bands
here but we can zoom around and take a look at some of the detail to understand
what this image actually looks like so the next step would be to take this data
open it into PCI and start working with it
but now we have a workflow for getting data from copernicus onto our computers
so that we can start to work with it this stuff looks amazing we might be
familiar with landside data but this blows it out of the water in terms of
the detail that we can see you just zoom in a little further start to see the
individual pixel level this is the level that we get it at 10 m spatial
resolution. Okay, I hope you enjoy the data. I hope this tutorial was useful and
happy data hunting!