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SEPAL is part of the Open Foris suite of tools. SEPAL allows users to query and process satellite data quickly and efficiently, tailor their products for local needs, and produce sophisticated and relevant geospatial analyses quickly. Harnessing cloud-based supercomputers and modern geospatial data infrastructures (e.g. Google Earth Engine), SEPAL enables access and processing of historical satellite data as well as newer data from Landsat and higher-resolution data from Europe's Copernicus programme.
SEPAL is a cloud computing-based platform for autonomous land monitoring using remotely-sensed data. It is a combination of Google Earth Engine and open source softwares ORFEO Toolbox, GDAL, R, R Studio Server, R Shiny Server, SNAP Toolkit, and OpenForis Geospatial Toolkit. It allows users to access powerful cloud-computing resources to query, access and process satellite data quickly and efficiently for creating advanced analyses.
SEPAL is currently in a BETA testing mode only. It is undergoing constant updates and improvements and has not reached a point of being considered a stable codebase. It works, of course...it's just not something we can call finished.
SEPAL is a project of the Forestry Division of the United Nations Food and Agriculture Organization (FAO) and funded by the Government of Norway.
Go HERE and enter your information
Login…
Login to SEPAL and give it a go!
The essentials…
There is no user manual as of yet…but the initial navigation should be relatively straightforward. However, before you get into it there are a few essential things you should know.
You are working in a secured cloud-based computing environment. In other words, you are not processing anything on your desktop but rather in a range of super-computers, or INSTANCES, located in a computing facility…somewhere. In the current case of SEPAL 2.0, these computers are part of the Amazon cloud. Specifically as of now you will be working on computers located in Ireland.
The image search, compositing, previewing and downloading is handled by Google Earth Engine. The Earth Engine is an amazing system and you can read more about it here: earthengine.google.com
SEPAL 2.0 works on the concept of ‘user budgets’. These budgets refer to a monthly US Dollar amount for processing capacity and storage capacity within the cloud-computing architecture. As BETA users of SEPAL, you have all been given 10 USD monthly for processing and storage. This may not seem like much…but the basic computer, or instance, costs less than 0.03 USD per hour to run! So you get quite a bit of processing for your ‘budget’. You can change the level of instance you are connected to and, depending on the power of the instance, the costs will increase more or less dramatically from the base instance. More on this later.
It should be noted that searching for data, compositing data and previewing the result of the searching and compositing do not count at all towards your monthly user budget!! You can do as much searching and testing of mosaicking as you want without charging your user account for processing time.
For more detailed instruction, please see the Tutorials section below!
What else can we do???
Processing
SEPAL 2.0 utility is expanded with user-contributed PROCESSING MODULES available through the ‘Processing’ button (e.g. the wrench).
Check out the kind of processing options available by clicking on ‘the wrench’…
Here we have access to:
RStudio - just general use of RStudio for anything you want to do with RStudio but with the processing power of the computing instance you select… Accuracy Assessment Design - a module to design a map accuracy assessment for raster or vector maps Accuracy Assessment Analysis - a module to analyze the results of a map accuracy assessment SAR Toolkit - a module for query and processing of Synthetic Aperture Radar (SAR) data GEO-processing (BETA) - a module to perform geo-processing on data you have in your workspace Visualize (BETA) - a very very basic module to view what you’ve processed
Each module starts an Amazon instance (basic) if one is not already running and processing time will be charged to your user account. If an Amazon instance is already started, then the modules will be run on the existing instance. It may take a few moments for a processing module to start if a new instance has to also be started simultaneously.
The Terminal
The terminal can be used to start instances, terminate instances and perform LINUX command-line functions on your workspace.
Start a Terminal by clicking on the symbol. You will be given the option to start an Amazon instance (with associated processing power and price per hour) or will be asked to join an existing session if one is available.
To terminate an instance go the terminal and type ‘exit’ at the command prompt. Then hit ‘ENTER’. You will be asked if you want to rejoin the session or ‘TERMINATE’ it. Press ’t’ to terminate and hit enter. The remote instance will shut down and you are FREE!!!
This is all I can include at the moment in the way of an introduction to the SEPAL platform. Please feel free to give it a try and e-mail me with comments or questions at erik.lindquist@fao.org. Or…better yet…post your question or suggestion to our support community at http://www.openforis.org/support/. Then we can all learn from each other.
How to get started building data in SEPAL
Some short standard operating procedures (SOP)
Change Detection in SEPAL...thanks to the United States Forest Service and the USAID CARPE Program
How to perform a stratified area estimation in SEPAL
How to use the SEPAL Open SAR Kit
GOFC/GOLD videos: Introduction to SEPAL
GOFC/GOLD videos: Stratified area estimation
Webinar Intro SEPAL 2.1 - 2019/07/11 EN
Webinaire Intro SEPAL 2.1 - 2019/07/12 FR
Overview ESA phi-week 2019. 2019/09/13 EN
Peatland mapping and monitoring webinar, 2020/03/18 EN
ESKEN webinar, Forest mask and Fragmentation, 2020/03/26 EN
In the new version of SEPAL, the interface has been overhauled to improve the user experience. Some new features in the new interface include: Sentinel 1 mosaics, Landsat and Sentinel 2 fusion, increased flexibility with image classification, inclusion of Jupyter Labs and many other features. The new version of SEPAL is also compatible with mobile devices.
Access to super computers means you can process huge data sets in a short amount of time that you would not be able to process on a laptop or desktop computer due to memory and processing power limitations. You can see the list of available super-computers when you open a terminal
In the processing tab, yes. In the app tab, not yet, the interfaces for applications are not 100% adapted to use on mobile phones.
Each user starts with 20 GB of storage in SEPAL. SEPAL also has a limit for monthly storage budget. Make sure you clean your data space once if you have finished processing. SEPAL is not intended to be a storage platform but a processing platform
For now the sign up process is manual, a member of the SEPAL team needs to approve each sign up request. Therefore, it can take up to a couple of days to get an account.
Questions can be posted on the SEPAL Google group or the Open Foris Community Support forum with the tag SEPAL
7. What are the compatible formats for training data inputs? I had the impression it was a sheet GoogleDoc?
Training data should be in a fusion table format. Training data can be loaded into SEPAL using the fusion table ID. Discussions with the Google Earth Engine team indicate that GoogleSheets will be used after Fusion Table get deprecated and we will use the same approach.
Both radar and optical mosaics can be exported at any resolution between 10 and 100 meters.
Yes! R can be used through Rstudio or Jupyter notebooks
It’s free for all our users! Each users gets a virtual budget so the SEPAL team can monitor the usage of the platform but it does not cost anything for the users.
Yes, there are a few options for exporting your data from SEPAL to your computer. You can export the data using the download interface through the folder structure in SEPAL. You can also use a SSH file client such as FileZilla or through the export through the export option in RStudio. The fastest way is through a SSH file client.
Results are kept in SEPAL for as long as you don’t delete them, but we advise you to regularly clean your working space
They do as good as when they are processed in GEE. Results obtained so far have proven satisfactory
There is the option to download metadata layers as bands when exporting a mosaic.
Google Sheets
OrfeoToolbox commands are accessible through the SEPAL terminal. There is a user interface in the Apps, Geoprocessing Tools BETA for Unsupervised change detection (IMAD) and image segmentation using the OrfeoToolbox.
Yes, there is an option to apply atmospheric correction in the mosaic corrections options.
Cela signifie que vous avez accès à des instances du serveur en ligne qui correspondent à des superordinateurs. La liste des instances disponibles est visible quand vous ouvrez un terminal (différentes RAM et CPU parallèles)
Sepal.io/ceo est toujours opérationnel, mais ne sera pas développé plus avant
3. Peut-on faire exactement les mêmes opérations sur SEPAL mobile (téléphone) que sur les ordinateurs ?
Pour les applications GEE oui, pour le traitement toutes les applications ne sont pas disponibles en version mobile (par exemple R-Shiny)
Nouvelle ergonomie pour une utilisation simplifiée, mosaiques radar, fusion des données pour la classification, accès à Jupyter Lab. SEPAL est aussi disponible sur support mobile.
Par défaut vous avez 20GB d’espace de stockage, qui peut être augmenté en fonction des besoins. S’adresser à un administrateur SEPAL. Aussi, il faut garder en tête que SEPAL est développé pour être une plateforme de traitement, pas de stockage. Une fois vos opérations terminées et les produits exportés, nous vous encourageons à nettoyer votre espace de travail.
6. Google Fusion Table sera fermé à partir de décembre 2019 Sépal fera quelque chose pour palier à cela?
Pour pallier la disparition des Tables de Fusion, SEPAL suivra la solution adoptée par GEE (vraisemblablement des GoogleSheets)
7. Pour charger les données d'apprentissage, quel est/sont les formats compatibles? j'ai eu l'impression que c'était un sheet googledoc
-> pour l’instant des Tables de Fusion, par la suite GoogleSheets
-> les mosaïques radar peuvent être exportées de 10m à 100m de résolution
Le temps pour un membre de l’équipe de vous ouvrir un compte, en général 24h
Sur le SEPAL Google group ou sur le forum Open Foris Community, avec le tag SEPAL
Oui un serveur rstudio est disponible et vous pouvez utiliser n’importe quel code en R (également Python, Perl). La plateforme SEPAL est gratuite
Oui vous pouvez soit utiliser la fonction download dans votre navigateur de l’espace de travail, soit via un client SSH comme FileZilla. Nous recommandons d’utiliser un client SHH.
Oui l’option est disponible pendant la création des mosaiques
Autant que disponible dans les catalogues GEE. Pour le moment, les résultats obtenus sont satisfaisants.
Oui, les metadonnées sont disponibles sous forme de bande dans les options de téléchargement.
Vous avez accès directement aux librairies OTB depuis le terminal. Si vous avez un code avec OTB, il pourra tourner depuis votre interface de choix 17. Pendant combien de temps le résultat des traitements est conservé dans SEPAL? Autant que vous les laissez sur la plateforme. Nous vous conseillons cependant de nettoyer votre espace de travail régulièrement et de supprimer les fichiers une fois les résultats téléchargés
Oui vous pouvez soit utiliser la fonction download dans votre navigateur de l’espace de travail, soit via un client SSH comme FileZilla. Nous recommandons d’utiliser un client SHH. Vous pouvez ensuite utiliser QGIS ou un autre SIG pour visualiser et manipuler vos résultats.