Your Processing Environment

Use of SNAP and QGIS on a CREODIAS Virtual Machine

 

The CREODIAS platform is designed to be flexible. Satellite data can be downloaded from the platform through a number of services like OGC, NFS, S3 and the CREODIAS Finder API. However, the platform has been designed to minimise the need to download large amounts of satellite data and perform processing and analysis of data on the CREODIAS platform itself. To facilitate this, users of CREODIAS can use a Virtual Machine (VM). Currently, a wide range of VM images are available that can be installed quickly on CREODIAS, currently there are 17 options. For Linux users, there are CentOS, Red Hat, SUSE and Ubuntu images available, as well as OpenVPN and OSGEO images. These are very useful for users that want to access and process large amounts of data. However, for simpler tasks the most commonly used OS, Windows is often more user-friendly.

After installation of a Windows-based VM, the CREODIAS platform can be accessed via Remote Desktop. From here the VM functions like you are working on any Windows PC. Programs like ESA SNAP or QGIS can be installed by the user itself as requested.

 

Satellite data access

Accessing the satellite data stored on the platform can be done through a mounted network drive in the File Explorer. This shows immediately the advantage of using a VM on the CREODIAS platform, there is no need to download any satellite data to your computer, they are already present and ready to be used for further processing inside the VM. Suitable satellite imagery can be searched in the CREODIAS Finder and be accessed by copying the file path into ESA SNAP, QGIS or any other preferred software and start working on it straightaway.

Through CREODIAS Finder it is also possible to create a task to convert Sentinel-2 L1C data to atmospherically correct L2A data. For this, any L1C image can be selected and ordered by adding the sen2cor processing task. It generates the L2A product directly and will be available within half an hour.

 

Screenshot of Windows VM environment

 

Use cases

Sentinel-2 data is often used to estimate health and development of agricultural crops. To achieve this through the VM in CREODIAS, a required Sentinel-2 image can be loaded directly into ESA SNAP and be pre-processed to biophysical parameters like NDVI, fAPAR or LAI. In the screenshot below, biophysical parameter processing of Sentinel-2 data in SNAP is shown, with fAPAR, fCover and LAI parameters shown.

 

Screenshot of Windows VM environment

Use potential

The use of a VM on CREODIAS offers a safe cloud-based access to large Sentinel and other satellite data sources data, as well as processing and analysis capabilities. This is all possible in a familiar (Windows) environment, without advanced programming and coding skills needed. The VM is highly customisable, it can easily be adapted to the user’s needs and wishes.