How to download Satellite Images from the USGS, ESA and Google Earth Engine

hello and welcome today I thought rather than showing you how you can process spatial data I would actually make a tutorial on how you can get your own datasets specifically satellite data from various sources for free to do your own research now first of all I want to introduce to you the earth Explorer from the US Geological Survey and this is a data portal for obtaining geospatial datasets from an extensive collection including Landsat satellite imagery radar data digital elevation models and so on secondly we will talk about the Copernicus open exit hub which is the place to go if you're looking for a data from any of these sentinel missions and then finally I want to give you a brief introduction on Google Earth engine which is actually my favorite place to go to when I want to download any datasets and the great thing about Google Earth engine is that you can access all those freely available satellite datasets right here and process them within this coding environment of the Earth engine and clip it select certain bands and that way you don't have to download a huge image which can be a gigabyte in size but rather clip the image to your specific study area select only the bands that you need and download this result which will be much smaller in size so let's get started and talk about earth Explorer first you will find the earth Explorer either by clicking on the link in the description or you can simply search for Earth Explorer and the USGS page will be the first one now to download any kind of data you do have to sign up for an account if you don't have one yet now you will need to provide a username and then your password and on the following pages it will also ask you what you will use the data for so scientific purposes for example but the registration is completely free so complete that and then you can go back to the earth Explorer and sign in now I already have an account and once you're logged in the page should look something like this so let's look for some data I like to search my data by location so change the geocoding method to address and place and I'd search for a place for example Paris show that hit Paris and France and here we are now let's narrow our search down a bit so we don't get hundreds of satellite images but only gets for example data that was collected in May 2020 so define your date range right here what you can also do is for example if you're only searching for summer months you can define a time span of a couple of years and then only select the months that you want for example June July August ok let's look for the data sets here are all the data available within the earthexplorer so as I said it's a huge collection for this example let's look at Landsat data you can see we have different image collections right here the Landsat level one data is not corrected for any atmospheric conditions but it can be downloaded right away so we will look at that and check the Landsat 8 satellite for example if you want the level to surface reflectance data that is corrected for atmospheric conditions you can check that as well these data sets cannot be downloaded directly but you will send a request this will be processed to get an email takes about an hour maybe and then you will get a link in the earth Explorer where you can download the data set so I've selected Landsat 8 for both the level 2 and level 1 collection and then we can add some additional search criteria which will most importantly be the cloud cover because usually we don't want super cloudy scenes where we can't see anything I don't know whether we'll have that in France in May let's just choose 20% and see if we find any scenes so go to results and great we can see we have found scene right here this is the Landsat 8 level 2 products of these surface reflectance data let's change here to the level 1 data and you can see we have two scenes right here if we want to look at them we can hit this icon and we will see our scene right here this is another one oh this is super cloudy so we would not want that all right now if you want to download this beautiful scene you can go to download options and here you have some suggestions I always go for the dieta file which will be the one below here and I already said they're huge in size so stay tuned for the Google Earth engine but if you want the entire scene just hit download the Geo two file right here if you're searching for multiple scenes it might be easier to add them all to a both download hitting this I can and do that for all the scenes that you want and then you can download them all at once now let's go back to the level 2 product and you might notice we don't have the download button right here this is because the level 2 product is only available on demand but there's no problem if you want any Landsat 8 level 2 data hit this basket icon right here and now you can see I have an item in my basket so I can look at this so here's my order and then I hit proceed to checkout and I will submit my order and it says an email has been sent to me notifying me that I've placed this order and once my order has been approved I will get another email directing me to the download link in the earthexplorer ok what if we want some digital elevation data then we go back to the earth Explorer and it's still searching for those scenes we don't want that anymore so unchecked all the Landsat products right here and then we also need to make sure that we change our search criteria down here because the SRTM that i'm going to show you is a data set that was not collected in May 20 20 so I'll just leave that blank remove the dates then I go to data sets go to digital elevation and the SRTM is right here and then you can choose from a void filled non boil fill the global data set I will for example take the void filled data right now so I'll check that and go to results and here is the void filled SRTM for the paris area we can look at this and we can download this as well similar to the level 1 Landsat data let's briefly talk about the Copernicus open access hub this is a data portal similar to the earth Explorer from the European Space Agency and this is the place to go to if you want to access any kind of data from these sentinel missions you can download sentinel day from the earthexplorer as well but this is limited to Sentinel 2 data I believe to get to this Copernicus hub just search for it and this will be the first result we will get to this page and to access the hop go down here and you will be directed to this page where you can search for data now to download any scenes again here you need to register for an account so go over here and sign up or login if you already have an account like me so I'm going to do that and now I'm logged in so let's search for some satellite data again we'll go to the Paris region so zoom in right here and then we can use this tool to draw a polygon of the area that we're interested click to finish it and now we'll search for all these scenes that intersect with this polygon within a given time frame now again we will limit the sensing period to May 2020 1st to 31st ok let's only get data from The Sentinel 2 mission for this example and also limit our cloud cover similar like this so put in 0 to 20 maybe okay let's see if we find anything ok nice so we have found 23 products and we can look at them here in map view so if we select a scene right here you can see they're turned dark now we can get some more info by hitting this eye button and we'll get this pop up with some more information on the data set and yeah for example here's the file name the satellite some more stuff down here so you can have a quick look and if you're satisfied with what you're seeing you can simply hit download right here I will not do that in this case ok so I think the Copernicus open exits app is pretty straightforward let's move to Google Earth engine which is probably a bit more confusing if you haven't used it before Google Earth engine looks like this it is a cloud-based platform with a huge catalog of satellite data and it allows you to analyze geospatial data on a planetary scale because you don't have to download a tremendous amount of data but can process everything within this platform today we're not going to do that we will simply exploit this large catalog and the functions provided by the coding environment from Google Earth engine to eclipse satellite data and just download small snippets of it again you do have to sign up for a Google Earth engine if you're strolling around YouTube you probably already have a Google account so you can use that I have already signed up so I'll log in and once you're logged in you can go to platform and code editor now this is what the code editor looks like so you have your scripts on the left side right here here's the script you're working on right now and here's the console this is the script I'm using to download Center to data I will put that in the description I will only walk you briefly through everything that I'm doing right here to not get too much into depth of Google Earth engine that will be another video some other time but yeah basically what you need to do let's again do that for Paris because that has been our example there's some old stuff I've been doing here so let's go to Paris and France and we're in Paris so again let's define a polygon and straw an area around Paris right here you can see up here we've gotten a new geometry called geometry - I'll actually delete the first one because I don't need that anymore and name the second one geometry so everything stays the same with in my code this is our area of interest let's load the centum to data we will create a variable called s - and this is going to be an image collection now within this image collection we want Sentinel 2 data which we define here we will filter all these Sentinel 2 images by the bounds of our geometry down here the next filter that we apply is a cloud filter so we only want images that have a cloudy pixel percentage less than 10% and then finally we want to filter that by date so previously we're searching for data from May 2020 so let's do that here as well and this will return a collection of images that all fulfill this criteria now if you're looking for a different data set for example and said you can always search for your data set up here hit for example this collection and down here it will tell you how you can import images from this collection so in this case you would substitute the compare Nicholson central two with this code snippet just put that here ok the next thing that I'm doing right here is clipping all my images within my image collection to our geometry so this part right here this is the definition of the function and here I'm executing it and then within my image collection I might have five images I might have 10 now I want to look at every image that fits my filter criteria and I want to potentially also export all the images that have been filtered now to do that we need to loop over our image collection we do that right here and as you might know Sentinel 2 data is multispectral so we have several bands but let's just say we're interested in the RGB bands so been to band 3 been four so for every image we only select those three bands and plot them down here and this is the code to actually export your image from this Earth engine environment and save that to your Google Drive so you will put the RGB image right here give some description so I will name that central to RGB plus the date of my image the scale is the resolution of your data so 10 meters in this time the region that we want is the geometry around Paris right here and we can create a new folder in my Google Drive Paris okay and if we run this you now concede that we have gotten a couple of new layers so those are snippets from all sentinel two scenes acquired during May 2020 over Paris and if we just don't show our geometry and zoom in you can see we have a clipped RGB image for every scene here are some clouds those are actually a lot of images maybe I should have narrowed down the filter criteria a bit if your image collection gets really large Google Earth engine gets really slow and my laptop also gets really loud so sorry about that anyhow now you would just look at all of those layers and find one that you like for example this one and then you go to text and you can see I've gotten a couple of new tasks and this task up here belongs to this RGB clip of our satellite image and if we run this you can see we get a task to initiate our image export and we can execute this and now this image will be saved to our Google Drive where we can download that to our computer now this might take some time depending on the size of your data but then you're good to go alright that's it for this tutorial thanks for watching as usual leave all your questions in the comments and until next time

Channel: Making Sense Remotely

Views: 12,912

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Keywords: download satellite images from usgs, download landsat 8 satellite images, earth explorer download image, earth explorer dem download, srtm download free, how to download sentinel 2 data, google earth engine download data, google earth engine download landsat, remote sensing tutorial, remote sensing, satellite imagery, how to download sentinel 2 data from copernicus, how to download satellite images from earth explorer, download satelite images

Id: uQvlTQoUWuQ

Length: 14min 21sec (861 seconds)

Published: Sun Jun 07 2020