Downloading and preprocessing Sentinel 2 images using the Semi-Classification Plugin in QGIS 3.0

hi everyone how's it going welcome to this tutorial my name is Mari Carmen and I will show you how to download and process Sentinel 2 images using the semi classification plugin in QGIS 3.0 ok so before we start with QGIS we need to go to the psyhov website we go to this website which is sie hope that Copernicus dot-eu and we click on open hub after clicking on up and hub we are going to get we're going to get a map and the website where we can find where we can find the satellite images or other data but we're not going to download it from here we just need to sign up or just to have a an account ok so if we click on sign up we're going to get this this window and in this window we have to complete all this information and then register after registering you are going to have a password and user name so when you have your password and your username you're ready to go to QGIS 3.0 so we open QGIS 3.0 if you have this folder you need to double click on QGIS desktop 3.0 point zero and then you wait for a little bit and you get QGIS so we need to install the plugin to install the plug-in we go to plugins manage and install plugins and here we're going to search for semi automatic classification plugin when you have this plugin you're going to find this button this button you will have installed plug-in you click on install plug-in and then you'll have your plugin installed after having your plugin installed you're going to have this this menu which is SCP when you have your SCP menu you go to show plug-in click on show plug-in and this is the new window of the plug-in then here we can do a lot of things we have lots of tools but for this tutorial we're going to use that download product we go to login data and here we have the option log-in sentinels here is the service is this one and you you have your username and your password you can say remember and and this plug-in will remember your information ok so now you have your your user and your password I'm going to to upload my study area which is this one this is a vector other okay so here I have my study area I want a satellite image from this area so we're going to look for that satellite image here you have the option search here you have Sentinel to product and here you have the search parameters we can create a rectangle around the study area and and then the coordinates are going to appear here so to create the rectangle we click on this plus button set area in the map and then click on on one corner just normal click and then right click on the opposite corner and the rectangle will appear so does the coordinates ok and now we can choose to drag the date in this case I wanted a from 2018 January 2018 to 3rd date to this date and then we can we can move the maximum cloud cover and the product and then we can click on find so we need to wait for a little bit until it finds the information okay so now here we have some results all of these are satellite images from different dates we have here a preview window so if we click on some of on one of the one of the images we're going to get a preview from the from the image in this case we have more information we have the cloud cover cloud cover is important the acquisition date and I am going to look for for an image that has not a lot of cloud cover for instance this one okay so this image is fine for me and the cloud cover is is minimum and I think it covers very well their study area so I'll download this image so we need to we need to delete the other images so the one that I selected was cloud cover this one so it's this one I'm going to select the ones above it okay now that they are selected I am going to delete the rows yes and now I am going to select the ones below damage okay now I have them selected and I'm going to delete these rows as well yes okay now we have the image that I want to download here we have the download options in case of Sentinel - it has all of these bands you can select which bands you want to download in this case I am going to download all of them so then this is not necessary and we are going to click on pre process images because we are downloading the image and then QGIS will purposes these images and then it will load the bands in QGIS this operation takes around one to two hours so I am NOT going to run it but if you want to download Sentinel two images this is the process that you have to follow then if you want to process them you purposes them with this button and then you only click on run after clicking on run it will take around one to two hours to download the image and to purposes very much as well if you have already a sentinel two image and you just want to press s then you go to this option which is for processing here in processing you will select Sentinel 2 here in Sentinel two you're going to selected the files where you have your your Sentinel 2 images in this case I have I have this this this folder so I'll select the folder and then it asks for the metadata file so here I have all my bands and then we need to introduce them mental data file the meta data file here it says MTD M s I so is this one and you say open and then you're you're going to have quantification volume and solar irradiance you can apply the atmospheric correction and then your your image will be persist you only have to click on run and this this operation also takes about one maybe less than one hour but around for a minute and then you run and you will have your your purposes images so for this case I will read it on the per processing and the downloading of the images and I'll just add them to QGIS the images are a raster files so I'll go to this button which is addressed earlier and I'll look for them so I don't look at them with the SCP plugin and I have two folders I have the first folder that is the one without Corrections for pre-processing and I have the second folder which is this with all the processed images so I have band 1 1 2 1 3 4 5 6 7 the the type of the file is ti FF 8 9 10 11 12 open so here I have all the bands for my satellite image these are images from The Sentinel two satellite okay so now what we can do with these satellite images is that we can we can create a natural color image or a fake color image and we also can calculate a nd V I which is the normalized difference vegetation index to do so we need to know more about the events of Sentinel - the Sentinel two bands are at this so one one is coastal aerosol band whose Blue Man 3 is green Banford red one five six seven vegetation red edge eight near-infrared 8 a 9 water vapor and 10 11 12 their shortwave infrared so this is very important because now we are going to we're going to create a a natural image and we are also going to calculate the NDVI okay so to create a natural color image we go to roster I don't have to here here in miscellaneous we're going to create build virtual roster here we're going to select only there to create a natural color image we need the blue green and red band the blue band is band 2 so we're going to select band - then band 3 and band 4 and we're going to say ok and we'll say run in background okay so now here we have a virtual roster and we're just going to give and give it another style we go to properties and here we're going to change the ones the red band will be band three green band one two and blue band band one okay so now here we have a natural color image if we go closer we can see natural colors in this image so this is it for this tutorial if you want to know more about QGIS for weather management check out the online courses of Hatari labs thank you and Cheers

Channel: Hatari Labs

Views: 63,592

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Length: 18min 40sec (1120 seconds)

Published: Mon May 07 2018