QGISSubmitted by admin on Wed, 2016-12-14 17:33
Running the QGIS Application within F-TEP
This service allows to run QGIS in the browser on any image either produced inside the F-TEP system or resulting from a query. QGIS (previously known as Quantum GIS) is a cross-platform free and open-source desktop geographic information system (GIS) application that provides data viewing, editing, and analysis.
The following tutorial describes how to acess and open data from F-TEP within QGIS. Further guidance as to performing other activities in QGIS can be found here.
Accessing F-TEP Explorer and selecting data
Perform a search specifying either an area of interest or a filter on products (for guidance see previous tutorial - Searching for data). The picture below shows the result of a search for Sentinel-1 products.
Open the Services panel on the left of the F-TEP Explorer page and within the GUI Applications select the QGIS service.
Start the QGIS Job
To define the input of the selected service a user can directly drag into the inputFile field the result(s) of a search or a result within the Databasket.
After filling the form containing the parameters of the service, by clicking the “Execute” button the service is started by the system and the user can follow the processing in the “JOB” panel.
The JOB panel shows all the run of services provide by F-TEP performed grouped by the server name. The QGIS service just launched can be found in the QGIS section of the JOB panel.
The job is identified by a number (Job ID, 785 in the picture above) and in a few seconds - depending on the nature of the service and on the size of the inputs - cycle through three different states:
- Fetching data
Graphical application - like QGIS - while in status "Processing" allows the user to open in the browser the interface of the application and to directly use the selected inputs. When the running QGIS application reaches Processing status, an icon is showed: the picture below show the icon and its tooltip (Go To GUI).
By clicking on the "Go To GUI" button a user is presented - in a new window - a login panel to access the graphical interface of the QGIS application. The picture below shows the login page: by clicking OK button a user directly access QGIS interface.
The picture below shows the QGIS interface opened in the browser: all the functionalities of the application are directly accessible.
To open the selected image as a raster layer in QGIS "S1A_IW_GRDH_1SSV_20151214T001822_20151214T001834_009030_00CF4C_7CAA", in the top bar menu
- open "Layer" menu
- select "Add Layer"
- select "Add Raster Layer"
In the new window that QGIS will open, navigate the filesystem and access the directory
this directory will contain all the input files selected in the launch phase. In this specifc scenario, a user will find the following folder
Open the folder S1A_IW_GRDH_1SSV_20151214T001822_20151214T001834_009030_00CF4C_7CAA and select the tiff image and press the Open button: in a few seconds, depending on the size of the image a user will see the tiff image in QGIS.