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* Enter '''[0 TO 10]''' in the cloud coverage Section
* Enter '''[0 TO 10]''' in the cloud coverage Section


Press the menu button again. The button will turn into a filter icon. Then enter a '''country name''' (e.g. Germany). As a result of the query you will get a list of entries.  
Press the menu button again. The button will turn into a filter icon. Then define the selected region by dragging a rectangle around the area of interest.


[[File:ss2.png]]
[[File:ss2.png]]
Line 36: Line 36:
* images that ideally have '''no cloud cover'''
* images that ideally have '''no cloud cover'''
* images that were taken in '''bright light'''.
* images that were taken in '''bright light'''.
* images that includes a maximum amount of complete tiles (with a minimum of tilted cut off black portions).
* images that includes a maximum amount of complete sub tiles (with a minimum of tilted cut off black portions). Eventually only those tiles which are complete (i.e. without clouds and black areas) will be of long-term value.
* images that '''contain land masses''' or at least '''islands''' or '''coastlines'''. We are not interested in Ocean pictures since we will add an artificial ocean later on.
* initially we should rather focus on '''populated areas''' in Europe.
* the chosen areas should ideally be '''adjacent''' to existing tiles that have been downloaded so that we get "growing" areas.
 


Once you've made a choice we suggest that you write down:
Once you've made a choice we suggest that you write down:
Line 55: Line 59:
Once the zip file is download '''unzip''' it in a directory of your choice. Make sure that your hard disc still has enough space left (approx. 10 GB).
Once the zip file is download '''unzip''' it in a directory of your choice. Make sure that your hard disc still has enough space left (approx. 10 GB).


''Note:'' Once QGIS is installed you could also download further tiles using the SCP plugin, however this approach lacks the nice thumbnails for introspection:
''Note:'' There are also alternative sentinel data browsers available:
 
1. The [http://maps.mundialis.de/ Mundialis] browser offers a nice search query that also works on smart phones.
 
2. Once QGIS is installed you could also download further tiles using the SCP plugin, however this approach lacks the nice thumbnails for introspection:


* [https://www.youtube.com/watch?v=fVS2Ls2bUbk Search and Download Sentinel-2 Images Using the Semi-Automatic Classification Plugin ]
* [https://www.youtube.com/watch?v=fVS2Ls2bUbk Search and Download Sentinel-2 Images Using the Semi-Automatic Classification Plugin ]
Line 77: Line 85:
Select '''Not Installed''' and choose the following plugins for installation in the list:
Select '''Not Installed''' and choose the following plugins for installation in the list:


* '''Semi-Automatic Classification Plugin'''
* '''QTiles'''
* '''QTiles'''
* OpenLayers Plugin


Also we recommend the following tools:


Once installed please right-click the toolbar area and enable the '''SCP Toolbar''' .
* Semi-Automatic Classification Plugin
* OpenLayers Plugin


=== Opening the Sentinel data in QGIS using the SCP plugin ===
Once you installed the Semi-Automatic Classification Plugin please right-click on the toolbar and enable the SCP toolbar.


Launch QGIS and choose '''Layer -> Add Layer -> Add Raster Layer'''  (or the associated toolbar '''checkboard''' button).
=== Using QGIS to create GeoTiffs for Sentinel-2 subtiles ===
Then navigate into the '''GRANULE''' directory. There choose the directory for the correct sub tile. The order of the tiles follows columns.
Inside the sub tile directory use the Ctrl button to '''choose multiple files at once''' - namly those which end on b2-b8, b8a, b11, b12:


'''b2.jp2, b3.jp2, b4.jp2, b5.jp2, b6.jp2, b7.jp2, b8.jp2, b8a.jp2, b11.jp2, b12.jp2'''
The current image data is stored in jp2 files which cover one subtile each for a certain spectral band. For each subtile there are about 12 different spectral bands covered. The goal of this chapter is to merge these jp2 files in order to get realistic colors. The end result should be a smaller georeferenced RGB file with realistic colors.  


Press '''Open''' to open them and wait for them to be loaded which might take about 10 secs.


For convenience you might want to press the '''Collapse All''' button in the Layers panel.
Let's start:


[[File:ss3.png]]
Download the [[File:sentinel.zip]] file and extract it in your home directory. It contains two files: createvrts.py and sentinel-marble.qml. Add the executable flag to the createvrts.py file.


Enter the '''GRANULE''' directory inside the .SAFE directory of the unzipped Sentinel-2 data. Then execute the createvrts.py createvrts.py script from inside that directory. It should create a '''vrts directory''' inside the GRANULE directory. Inside this directory you should find several .vrt files.


Now press the rainbow colored "Band set" button in the SCP toolbar. All files should appear in the upper section. Now apply the following steps:
Now launch QGIS. Press '''Ctrl-Shift-R''' (or '''Layer->Add Layer->Add Raster Layer'''). We'd like to load several .vrt files at once. However loading all would most likely require too much memory. So we have to load them in batches: Using the Ctrl-Key select the first six .vrt files inside the newly created vrts directory. Then press '''Open'''.
* Press '''Select All'''
* Press '''Add rasters to set'''
* In the middle to the right press the '''Sort by Name''' button
* In the '''Quick wavelength settings''' press the drop down list combobox, scroll down and choose '''Sentinel-2 [bands 2, 3, 4, ...]''' (if it is Sentinel-2 right from the start you might need to change to a different entry and back to Sentinel-2 to apply the correct wave length band sets).
* Press '''Create virtual raster of band set'''
* Enter a '''band_set.vrt''' as a file name.
* Press '''Close'''
* Then in the SCP Toolbar choose RGB first to be 4-3-2 '''then change it to be 3-2-1''' from the combobox (only after changing the correct color will be applied).


You should see a colorized version of your loaded tiles now. We suggest that you tweak the colors by right clicking on the vrt file entry on the right and press "Properties". In the Band rendering section we suggest that you make the following adjustments:
(In case QGIS crashes on opening the vrt it might be due to a corrupt jp2 file. In that case try to find out which jp2 is the culprit by trying to load the jp2 files into QGIS one by one via the Add Raster Layer feature. Once the corrupted jp2 is identified you can use the following workaround: copy it over by the jp2 with the closest band number. This will unfortunately result in a slightly different color shade).


[[File:ss3b.png]]
Now we want to apply proper colorization and styling: The styling is stored inside the sentinel-marble.qml file (short for QGIS markup language - so it's NOT a Qt Quick file).


* '''Right-click''' on the '''first''' (file) '''entry''' in the Layers panel.
* Press '''Properties'''.
* Press the '''Style button''' in the lower left corner
* Press '''Load Style''' and load the '''sentinel-marble-qml''' file.


Red Band: Band 03 - 398 2310


Green Band: Band 02 - 630 1962
[[File:style.jpg]]


Blue Band: Band 01 - 851 1903


* Press '''Apply'''. As a result the color of the tile should change to something more vivid.
* Right-click on the first (file) entry in the Layers panel again and choose '''Styles->Copy Style'''
* Then right click on all other (file) entries in the Layers panel and choose '''Styles->Paste Style''' for each entry.


In the Resampling section choose


* Zoomed: in '''Bilinear''' out '''Average''' Oversampling 2,00
As a temporary result you should see something like this:
* Press '''Apply'''


As a result you should now see a nice relatively realistic looking rendering of the sentinel data.


[[File:sentinel6tiles.jpg]]


[[File:ss4.png]]


[[File:sentinel_closeup.jpg]]


You can zoom into it using the mouse scroll wheel down to street level (10m per pixel).


Now we want to save the resulting virtual tiles into actual GeoTIFF files:
* Right-click on the first (file) entry in the Layers panel.
* Choose '''Rename'''. Then copy the file name using '''Ctrl-C''' and press '''Enter'''.
* Right-click on the first (file) entry in the Layers panel.
* Choose '''Save As'''


[[File:ss5.png]]


[[File:saveas.jpg]]


''Note:''


For further illustration we also recommend this [https://www.youtube.com/watch?v=HbxbbGyHjNs video].
* As an '''Output mode''' in the dialog choose '''Rendered Image'''.
* Click  '''Browse''' Button in the '''Save As field''', navigate to the tif directory inside the GRANULE directory. Press '''Ctrl+V''' to paste the layer name.
* Enable the '''Create Options''' checkbox, choose '''JPEG Compression''' as a profile. Change '''JPEG_QUALITY''' to '''85'''.  
* Press '''Ok''' and fetch a cup of coffee while the progressbar goes up to 100%.
* ''Repeat this procedure for all other entries.''


For more information please consult the [https://media.readthedocs.org/pdf/semiautomaticclassificationmanual-v4/latest/semiautomaticclassificationmanual-v4.pdf Documentation]
* Alternatively, you may download the [[File:Geotiff_Saver.zip]] script, and add it to Qgis, by going to the Processing Toolbox (you may open it by pressing Ctrl + Alt + T,  if you can't find it, enable it in the Plugins settings) and choosing "Add script from file", under Scripts > Tools.  
* Specify a folder to save in, a style file ( sentinel-marble.qml ), and the layers to save and press run. It will automatically go through those layers, add the style and save the tiffs. You may then compress them using the GDAL command below.


''Questions: ''


''1. are there other ways how we could achieve more realistic and better colors?''
The resulting GeoTIFF files will contain the rendered image in RGB representation without storing each band. This is lighter on memory and is better suited for tile processing. As the GeoTIFF files amount to about '''75 MB''' they are also better suited for long-term storage and data exchange than the original jp2 files.  (if you forgot to enable the compression profile you can also compress the files using: gdal_translate  -co COMPRESS=JPEG -co JPEG_QUALITY=85 inputfile.tif outputfile.tif )


=== Using QGIS to create GeoTiffs for Sentinel-2 subtiles ===
It's important that you keep these GeoTIFF files (e.g. on a USB disk) to allow for recreating the slippy map tiles later on.


Download the [[File:sentinel.zip]] [sentinel.zip sentinel.zip] file and extract it in your home directory. It contains two files: createvrts.py and sentinel-marble.qml. Add the executable flag to the createvrts.py file.
Once you are done with creating the first batch of GeoTiffs quit QGIS and restart it.
Then repeat the steps in this chapter for the other vrt files until there is a GeoTIFF file for every vrt file.


Enter the '''GRANULE''' directory inside the .SAFE directory of the unzipped Sentinel-2 data. Then execute the createvrts.py createvrts.py script from inside that directory. It should create a '''vrts directory''' inside the GRANULE directory. Inside this directory you should find several .vrt files.
Later on once you've downloaded more adjacent datasets from the Sentinel SciHub you can combine the GeoTIFF files:


Now launch QGIS. Press '''Ctrl-Shift-R''' (or '''Layer->Add Layer->Add Raster Layer'''). We'd like to load several .vrt files at once. However loading all would most likely require too much memory. So we have to load them in batches: Using the Ctrl-Key select the first six .vrt files inside the newly created vrts directory. Then press '''Open'''.


Now we want to apply proper colorization and styling: The styling is stored inside a .qml file (short for QGIS markup language - so it's NOT a Qt Quick file): Save the [sentinel-marble.qml sentinel-marble.qml] style file in a central place on your hard disc.
[[File:twodatasets.jpg]]


* '''Right-click''' on the '''first''' (file) '''entry''' in the Layers panel.
=== Tile Creation ===
* Press '''Properties'''.
Press Ctrl-Shift-R (or Layer->Add Layer->Add Raster Layer) and load all GeoTIFFs that you've created so far.  
* Press the '''Style button''' in the lower left corner
* Press '''Load Style''' and load the '''sentinel-marble-qml''' file.
* Press '''Apply'''. As a result the color of the tile should change to something more vivid.
* Right-click on the first (file) entry in the Layers panel again and choose '''Styles->Copy Style'''
* Then right click on all other (file) entries in the Layers panel and choose '''Styles->Paste Style''' for each entry.


Now we want to save the resulting virtual tiles into actual GeoTIFF files:
'''IMPORTANT: Before you start creating the tileset check the properties dialog: Make sure that all GeoTiff subtiles have "Bicubic" and "Average" enabled.''' This needs to be re-enabled after GeoTIFF generation!  Otherwise your tiles will be rendered using the low-quality nearest neighbor resampling approach.
* Right-click on the first (file) entry in the Layers panel.
* Choose '''Rename'''. Then copy the file name using '''Ctrl-C''' and press '''Enter'''.
* Right-click on the first (file) entry in the Layers panel.
* Choose '''Save As'''
* As an '''Output mode''' in the dialog choose '''Rendered Image'''.
* Click  '''Browse''' Button in the '''Save As field''', navigate to the tif directory inside the GRANULE directory. Press '''Ctrl+V''' to paste the layer name.
* Press '''Ok''' and fetch a cup of coffee while the progressbar goes up to 100%.
* ''Repeat this procedure for all other entries.''
 
The resulting GeoTIFF files will contain the rendered image in RGB representation without storing each band. This is lighter on memory and is better suited for long-time storage and tile processing.
 
Once you are done with creating the first batch of GeoTiffs repeat the steps in this chapter for the other vrt files until there is a GeoTIFF file for every vrt file.


=== Tile Creation ===
[[File:sentinel_netherlands.jpg]]


With the new sentinel layer loaded and proper band sets in place we can now start to create our own tiles:
With the new sentinel layer loaded and proper band sets in place we can now start to create our own tiles:
Line 190: Line 181:
* In the ''Extent'' section choose '''Layer Extent'''
* In the ''Extent'' section choose '''Layer Extent'''
* In the ''Zoom'' section choose '''14''' as a maximum zoom level
* In the ''Zoom'' section choose '''14''' as a maximum zoom level
* Choose '''JPG''' as a file format
* Choose '''85%''' as the Compression level
* In the ''Parameters'' section enable '''Make lines appear less jagged''' and '''Render tiles outside of layers extents (within combined extent)'''.
* In the ''Parameters'' section enable '''Make lines appear less jagged''' and '''Render tiles outside of layers extents (within combined extent)'''.




[[File:ss6.png]]
[[File:qtiles.jpg]]


''Questions: ''
''Questions: ''
Line 199: Line 192:
''1. Are there any other alternatives to using QTiles? Any better QGIS plugins than this?''
''1. Are there any other alternatives to using QTiles? Any better QGIS plugins than this?''


''2. How can we merge multiple datasets?''
=== Tileset postprocessing ===
The color range in the sentinel-marble.qml is chosen to allow for wide post processing. The idea is that a complete tile set can be easily batch-processed using image-magick or opencv.
 
Currently we are using this command inside the sentinel2 directory to apply a better '''gamma value''' and '''saturation''' to the whole dataset (level 1-14). This requires the graphicsmagick and parallel package to be installed.
 
<source lang="bash">
find -type f -name "*.jpg" | parallel --progress convert  -type TrueColor -gamma 1.33 -modulate 100,110,100 {} {.}.jpg
</source>


== Creating as custom DGML file for the Sentinel 2 data set ==
Since level 14 is at the edge of the highest resolution we apply an '''additional unsharp mask filter''' to it:


Creation of the DGML file should mostly be compatible with
<source lang="bash">
find -type f -name "*.jpg" | parallel --progress convert -type TrueColor -unsharp 1.75x1.75 {} {.}.jpg
</source>


[https://techbase.kde.org/Marble/OSMSlippyMaps How to integrate OSM "slippy" maps into Marble]
== Compiling Marble with support for the Sentinel 2 data ==
 
Technically marble's source code since version 16.08 has experimental support for the Sentinel 2 Satellite Map theme built-in already.
In order to enable the vector map theme you need to pass the cmake config option
 
-DEXPERIMENTAL_SENTINEL2_MAP=ON
 
So in order to compile Marble with vector tile support just compile it as described here:
 
https://marble.kde.org/sources.php
 
and just add the config option above, e.g.
 
<source lang="bash">
cmake  -DEXPERIMENTAL_SENTINEL2_MAP=ON ~/marble/sources
</source>
 
You can also enable this option in a more user-friendly way using the cmake-gui application.


== Deployment on the server ==
== Deployment on the server ==


For deploying the tiles on the server follow
For deploying the RGBA-GeoTIF-files and the tiles on the server you can mostly follow the access instructions at:


[https://techbase.kde.org/Marble/ServerUpload Upload to our KDE server]
[https://techbase.kde.org/Marble/ServerUpload Upload to our KDE server]
There is one difference: for the tiles we need to use the '''server darwini''' instead of depot.
=== Tiles ===
For the actual upload of the tiles you can use rsync. From the current local sentinel2 folder you could e.g. call:
<source lang="bash">
rsync -av --progress 13 14 [email protected]:/srv/www/maps.kde.org/earth/sentinel2
</source>
to upload level and 13, 14.
=== RGBA GeoTiff ===
The RGBA-GeoTIF files are stored inside the '''sentinel2 directory''' of the marble user on the KDE server. Before you upload them make sure that the tif files are stored inside a directory named "tif" that is stored in the following directory hierarchy:
S2A_OPER_PRD_MSIL1C_PDMC_20160315T113406_R065_V20150826T102655_20150826T102655.SAFE/GRANULE/tif
Then for uploading you can do:
<source lang="bash">
rsync -av --progress S2A_OPER_PRD_MSIL1C_PDMC_20160315T113406_R065_V20150826T102655_20150826T102655.SAFE [email protected]:~/sentinel2
</source>

Latest revision as of 08:05, 21 October 2016

Satellite Map Theme based on the Sentinel 2 Mission

Introduction/Motivation

This page is about the process that allows to create a satellite map theme for Marble based on the Sentinel data.

Sentinels Scientific Data Hub

Registering at the SciHub

Go to the Registration website of the SciHub and enter your name, username, password, e-Mail and country. As a domain you can choose "Land" and "Research" for the usage.

Once you press the Register button you will receive an e-Mail which allows you to finalize your registration in the SciHub system by pressing the included link.

As an alternative to creating your own login you can use "guest/guest" as a username/password when logging in.

Looking for data

Go to the SciHub website and press the Login Button to enter it. On the right side you can press the layers button to choose between the Hybrid, Road (OpenStreetMap) and Satellite map (Blue Marble/LandSat) for orientation.

Now we are ready to query some actual Sentinel data. In order to limit our query to useful entries we recommend these adjustments: Press the menu button on the left of the query line edit to enter the Advanced Search

  • Check Mission: Sentinel-2
  • Enter [0 TO 10] in the cloud coverage Section

Press the menu button again. The button will turn into a filter icon. Then define the selected region by dragging a rectangle around the area of interest.

You can browse through the pages. The thumb nails give you an idea about the quality of the photographic images. You can press the "eye" button to get an enlarged version of the thumbnail and to get more information.

  • images that contain an area that hasn't been included in the map theme yet
  • images that ideally have no cloud cover
  • images that were taken in bright light.
  • images that includes a maximum amount of complete sub tiles (with a minimum of tilted cut off black portions). Eventually only those tiles which are complete (i.e. without clouds and black areas) will be of long-term value.
  • images that contain land masses or at least islands or coastlines. We are not interested in Ocean pictures since we will add an artificial ocean later on.
  • initially we should rather focus on populated areas in Europe.
  • the chosen areas should ideally be adjacent to existing tiles that have been downloaded so that we get "growing" areas.


Once you've made a choice we suggest that you write down:

  • the id of the entry (which you can retrieve by pressing the "eye" icon for the entry and copy the id from the title line.
  • and the download url

in a text file. Good examples are:

id: S2A_OPER_PRD_MSIL1C_PDMC_20160508T220612_R008_V20160508T104027_20160508T104027 url: https://scihub.copernicus.eu/dhus/odata/v1/Products('4658007a-76a0-455c-bb9a-d9e789b5e1e3')/$value

id: S2A_OPER_PRD_MSIL1C_PDMC_20160508T221741_R008_V20160508T104027_20160508T104027 url: https://scihub.copernicus.eu/dhus/odata/v1/Products('0ded3149-d971-4524-ab80-536ffc1cbb55')/$value

Now click the download link to download the tile. The download will amount to 4-7GB on average. Even if the download gets aborted in the browser it should be possible to continue the download later on. Depending on the connection the download might take a few hours. At times the SciHub server has temporary maintenance down times.

Once the zip file is download unzip it in a directory of your choice. Make sure that your hard disc still has enough space left (approx. 10 GB).

Note: There are also alternative sentinel data browsers available:

1. The Mundialis browser offers a nice search query that also works on smart phones.

2. Once QGIS is installed you could also download further tiles using the SCP plugin, however this approach lacks the nice thumbnails for introspection:

Using QGIS to edit the Sentinel 2 data

QGIS installation

In order to process the data you need to install QGIS. On Ubuntu/Debian you can do this e.g. by opening a terminal and type:

sudo apt-get update

Type in a terminal:

sudo apt-get install qgis

Installing the required plugins

Launch QGIS and enter the Plugins menu. There choose Manage and Install Plugins. Select Not Installed and choose the following plugins for installation in the list:

  • QTiles

Also we recommend the following tools:

  • Semi-Automatic Classification Plugin
  • OpenLayers Plugin

Once you installed the Semi-Automatic Classification Plugin please right-click on the toolbar and enable the SCP toolbar.

Using QGIS to create GeoTiffs for Sentinel-2 subtiles

The current image data is stored in jp2 files which cover one subtile each for a certain spectral band. For each subtile there are about 12 different spectral bands covered. The goal of this chapter is to merge these jp2 files in order to get realistic colors. The end result should be a smaller georeferenced RGB file with realistic colors.


Let's start:

Download the File:Sentinel.zip file and extract it in your home directory. It contains two files: createvrts.py and sentinel-marble.qml. Add the executable flag to the createvrts.py file.

Enter the GRANULE directory inside the .SAFE directory of the unzipped Sentinel-2 data. Then execute the createvrts.py createvrts.py script from inside that directory. It should create a vrts directory inside the GRANULE directory. Inside this directory you should find several .vrt files.

Now launch QGIS. Press Ctrl-Shift-R (or Layer->Add Layer->Add Raster Layer). We'd like to load several .vrt files at once. However loading all would most likely require too much memory. So we have to load them in batches: Using the Ctrl-Key select the first six .vrt files inside the newly created vrts directory. Then press Open.

(In case QGIS crashes on opening the vrt it might be due to a corrupt jp2 file. In that case try to find out which jp2 is the culprit by trying to load the jp2 files into QGIS one by one via the Add Raster Layer feature. Once the corrupted jp2 is identified you can use the following workaround: copy it over by the jp2 with the closest band number. This will unfortunately result in a slightly different color shade).

Now we want to apply proper colorization and styling: The styling is stored inside the sentinel-marble.qml file (short for QGIS markup language - so it's NOT a Qt Quick file).

  • Right-click on the first (file) entry in the Layers panel.
  • Press Properties.
  • Press the Style button in the lower left corner
  • Press Load Style and load the sentinel-marble-qml file.



  • Press Apply. As a result the color of the tile should change to something more vivid.
  • Right-click on the first (file) entry in the Layers panel again and choose Styles->Copy Style
  • Then right click on all other (file) entries in the Layers panel and choose Styles->Paste Style for each entry.


As a temporary result you should see something like this:




Now we want to save the resulting virtual tiles into actual GeoTIFF files:

  • Right-click on the first (file) entry in the Layers panel.
  • Choose Rename. Then copy the file name using Ctrl-C and press Enter.
  • Right-click on the first (file) entry in the Layers panel.
  • Choose Save As



  • As an Output mode in the dialog choose Rendered Image.
  • Click Browse Button in the Save As field, navigate to the tif directory inside the GRANULE directory. Press Ctrl+V to paste the layer name.
  • Enable the Create Options checkbox, choose JPEG Compression as a profile. Change JPEG_QUALITY to 85.
  • Press Ok and fetch a cup of coffee while the progressbar goes up to 100%.
  • Repeat this procedure for all other entries.
  • Alternatively, you may download the File:Geotiff Saver.zip script, and add it to Qgis, by going to the Processing Toolbox (you may open it by pressing Ctrl + Alt + T, if you can't find it, enable it in the Plugins settings) and choosing "Add script from file", under Scripts > Tools.
  • Specify a folder to save in, a style file ( sentinel-marble.qml ), and the layers to save and press run. It will automatically go through those layers, add the style and save the tiffs. You may then compress them using the GDAL command below.


The resulting GeoTIFF files will contain the rendered image in RGB representation without storing each band. This is lighter on memory and is better suited for tile processing. As the GeoTIFF files amount to about 75 MB they are also better suited for long-term storage and data exchange than the original jp2 files. (if you forgot to enable the compression profile you can also compress the files using: gdal_translate -co COMPRESS=JPEG -co JPEG_QUALITY=85 inputfile.tif outputfile.tif )

It's important that you keep these GeoTIFF files (e.g. on a USB disk) to allow for recreating the slippy map tiles later on.

Once you are done with creating the first batch of GeoTiffs quit QGIS and restart it. Then repeat the steps in this chapter for the other vrt files until there is a GeoTIFF file for every vrt file.

Later on once you've downloaded more adjacent datasets from the Sentinel SciHub you can combine the GeoTIFF files:


Tile Creation

Press Ctrl-Shift-R (or Layer->Add Layer->Add Raster Layer) and load all GeoTIFFs that you've created so far.

IMPORTANT: Before you start creating the tileset check the properties dialog: Make sure that all GeoTiff subtiles have "Bicubic" and "Average" enabled. This needs to be re-enabled after GeoTIFF generation! Otherwise your tiles will be rendered using the low-quality nearest neighbor resampling approach.

With the new sentinel layer loaded and proper band sets in place we can now start to create our own tiles:

Press Plugins -> QTiles -> QTiles then

  • In the Output section choose Directory and browse to your directory of choice where the tiles should be stored
  • Enter sentinel2 as a Tileset name
  • In the Extent section choose Layer Extent
  • In the Zoom section choose 14 as a maximum zoom level
  • Choose JPG as a file format
  • Choose 85% as the Compression level
  • In the Parameters section enable Make lines appear less jagged and Render tiles outside of layers extents (within combined extent).


Questions:

1. Are there any other alternatives to using QTiles? Any better QGIS plugins than this?

Tileset postprocessing

The color range in the sentinel-marble.qml is chosen to allow for wide post processing. The idea is that a complete tile set can be easily batch-processed using image-magick or opencv.

Currently we are using this command inside the sentinel2 directory to apply a better gamma value and saturation to the whole dataset (level 1-14). This requires the graphicsmagick and parallel package to be installed. 

find -type f -name "*.jpg" | parallel --progress convert  -type TrueColor -gamma 1.33 -modulate 100,110,100 {} {.}.jpg

Since level 14 is at the edge of the highest resolution we apply an additional unsharp mask filter to it: 

find -type f -name "*.jpg" | parallel --progress convert -type TrueColor -unsharp 1.75x1.75 {} {.}.jpg

Compiling Marble with support for the Sentinel 2 data

Technically marble's source code since version 16.08 has experimental support for the Sentinel 2 Satellite Map theme built-in already. In order to enable the vector map theme you need to pass the cmake config option 

-DEXPERIMENTAL_SENTINEL2_MAP=ON

So in order to compile Marble with vector tile support just compile it as described here:

https://marble.kde.org/sources.php

and just add the config option above, e.g. 

cmake  -DEXPERIMENTAL_SENTINEL2_MAP=ON ~/marble/sources

You can also enable this option in a more user-friendly way using the cmake-gui application.

Deployment on the server

For deploying the RGBA-GeoTIF-files and the tiles on the server you can mostly follow the access instructions at:

Upload to our KDE server

There is one difference: for the tiles we need to use the server darwini instead of depot.

Tiles

For the actual upload of the tiles you can use rsync. From the current local sentinel2 folder you could e.g. call: 

rsync -av --progress 13 14 [email protected]:/srv/www/maps.kde.org/earth/sentinel2

to upload level and 13, 14.

RGBA GeoTiff

The RGBA-GeoTIF files are stored inside the sentinel2 directory of the marble user on the KDE server. Before you upload them make sure that the tif files are stored inside a directory named "tif" that is stored in the following directory hierarchy:

S2A_OPER_PRD_MSIL1C_PDMC_20160315T113406_R065_V20150826T102655_20150826T102655.SAFE/GRANULE/tif

Then for uploading you can do: 

rsync -av --progress S2A_OPER_PRD_MSIL1C_PDMC_20160315T113406_R065_V20150826T102655_20150826T102655.SAFE [email protected]:~/sentinel2
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