Help Content > Import Data > Download > Sentinel-1 Multidownloader

Purpose

This tool allows one to perform a query and download of Sentinel data from the Alaska Satellite Facility - ASF - (https://search.asf.alaska.edu) and Copernicus Data Space (https://dataspace.copernicus.eu/browser). At least one of the accounts with login credentials is required. The tool considers the accounts specified in User Accounts session in the Preferences Common.

Please note: To take advantage of the ASF, users have to login at least once on the ASF web browser portal and set a Study Area and accept the Terms Of Service for that account before performing the tool. Moreover, to enable the download via API, username and password must not be composed of special characters (even though the web interface allows these characters).

Technical Note

This tool performs a search for Sentinel data according to the query built through the input parameters. The downloaded data has to be decompressed and imported using the proper SARscape tools for further processing.

When started from the SARscape graphical user interface (under Import Data->Sentinel-1 Multidownload), the downloader is executed as a stand-alone, detached window. In this way, the downloading process does not depend on ENVI: you can even close ENVI while the downloader will continue to run. Under Linux, we use the "xterm" application to spawn the downloader into a stand-alone terminal: please make sure that this application is already installed on the machine where you are using SARscape. Xterm is usually available by default on most of the available Linux distributions or can be easily installed through the various distribution repositories (e.g., under RHEL/CentOS, simply run "yum install xterm" as administrator to install it). However, it is not possible to start the download while another process is running on the same working directory. If this happens, the first process will be killed and has to be resumed again.

Progress File

When at least one full data is downloaded, a Progress File named as defined in the Output tab is created in the output directory. This file can be used to skip already downloaded files which match the query. This file contains a list of all the data which are completely downloaded and the MD5 match the one provided by ASF or Copernicus Data Space. When a second request is preformed using the Sentinel Data Download tool, it is possible to set an already existing Progress File in the Progress File field. The software makes the following steps

•creates a list of needed files which fulfill the query created by the user using the provided parameters

•check if files in this this list are already present in the Progress File (if provided). If they are present, the files are not downloaded (again) and are skipped

•If a file is already downloaded, present in the output directory and the list of needed files but not in the Progress File, the software performs a MD5 check with the file present on ASF or Copernicus Data Space servers and if they match, the Progress file is actualized with this acquisition.

This functionality is helpful when an archive has to be updated with new files.

IMPORTANT: never use the same Progress File when another download is already active on the same Progress File!

Concurrent downloads

One account allows a maximum of multiple concurrent download. Multiple different download can be launched with this tool but it is imperative to use multiple different progress files.

Please note: According to the connection speed the download of a single image can take up to several hours.

Please note: Precisoe/restituted orbit files are not included in the downloaded file and have to be downloaded separately using the proper SARscape tool. More information can be found here.

Preview Mode

Small previews will be downloaded in the output folder instead of the full size SAR data. Note: Preview will be downloaded only for GRD data (Sentinel-1). Each preview is composed by a .png file containing the quick view image and a .kml file, which contains the footprint polygon and the quick view .png draped. By clicking on the footprint polygon, the following information are displayed: Satellite ID, Acquisition mode, Polarization, Orbit Direction, Absolute Orbit, Relative Orbit and filename. This is helpful in case only one track has to be downloaded but the relative orbit is not known a priori. Defining a region of interest and entering in the Preview Mode allows the user to have an overview of all the acquisitions on the interested area. Afterwards, based on these new acquired information, the search parameters can be adapted in order to match the desired request and the preview mode can be disabled (Preview Only = FALSE) in order to download the SAR data.

In the example below, the preview .kml, displayed in Google Earth, of two tracks on the same area of interest is shown. Clicking of the preview footprint polygon a balloon displaying acquisition information is shown.

The following color code is used for the footprint polygons:

Yellow SLC

Red RAW

Carmine GRD

Blue S2MSI1C

White other

Preview

Input Files

Optional Input Files

Input file(s) name of the image to be used as geographic reference for the search query. These files are mandatory if no shapefile or coordinate box is given as a reference. These files can be geocoded files, slant range or ground range files. However, the data type of the whole list has to be the same.

Optional Files

Geographical region

A vector file (.shp), or a Google Earth file (.kml or .kmz) can be upload to specify a region of interest. The AOI file must have at least 4 vertices. All acquisitions inside or intersecting this polygon are returned. The shapefile must be in GEO-GLOBAL cartographic system.

Parameters - Principal Parameters

Select Download Service

Select the download service between ASF and DataSpace.

Geographic Region

Box coordinates. All acquisitions inside or intersecting this box are returned. These fields have to be left empty if a shapefile is used as spatial reference. Co-ordinate decimal values must be entered using the dot (e.g. 29.30) and not the comma (e.g. 29,30) character.

West

The Westernmost cartographic co-ordinate (in decimal degrees).

North

The Northernmost cartographic co-ordinate (in decimal degrees).

East

The Easternmost cartographic co-ordinate (in decimal degrees).

South

The Southernmost cartographic co-ordinate (in decimal degrees).

From

Sensing period start date (day-MONTH-year), dd-MMM-yyyy, (01-JAN-1970). Note: The month must be provided as the name of the month (e.g., 'January', 'February', 'March', etc.); numerical values are not accepted.

Sensing period stop date (day-MONTH-year), dd-MMM-yyyy, (01-JAN-1970). In case the end date is not defined by users, the current time of the processing is considered. Note: The month must be provided as the name of the month (e.g., 'January', 'February', 'March', etc.); numerical values are not accepted.

Preview Only

With this flag on, the Sentinel Downloader is entering in Preview Mode. More information in the technical note.

Note: Preview will be downloaded only for Sentinel-1 GRD data.

Unzip Files

With this flag on, the downloaded files will be unzipped. to the directory selected in the Output Files.

Check MD5 After Download

With this flag set to true, the tool will not check if the MD5 of the downloaded file match with the one provided by ASF or Copernicus Data Space. This option helps to save time in case of downloading a large dataset, but it does not ensure the total reliability of the the downloaded files.

Orbit Direction

Filter for orbit direction (Ascending, Descending, ALL). This parameter is optional.

Product Type

Filter for product type (SLC, GRD, RAW, Ocean, ALL). This parameter is optional.

Acquisition Mode

Filter for acquisition mode (IW, EW, WV, SM, ALL). This parameter is optional.

Relative Orbit

Filter for relative orbit (e.g. 1, 2, 3... ). This parameter is optional.

Polarization Mode

Filter for polarization mode (VV VH, HH, HV, Dual VV, Dual HV, Dual VH, Dual HH, ALL). This parameter is optional.

Wait For Completion

If set to false, once the downloading process starts, the license gets unlocked and the panel can be closed, the downloading process runs in background in the terminal panel.

Repositories

It allows to input a list of folders (separated by ;), the Multidownloader will search a .zip file matching the query in those folders before downloading it. If a file is found the MD5 will be checked and, if correct and the corresponding option is set to true, the file will be extracted. In this case the file won’t be downloaded from the server, saving time. (C:\download_repo_1\; D:\download_repo_2\;...)

NOTE: If the “delete after extraction” flag is set to True the files in the repository will be deleted once the extraction is completed!

ASF Login - USERNAME

Username of Alaska Satellite Facility credentials. This field is optional only if the Copernicus Data Space login is inserted.

ASF Login - PASSWORD

Password of Alaska Satellite Facility login credentials. This field is optional only if the Copernicus Data Space login is inserted.

ASF concurrent download

Maximum number of simultaneous performed download (available download from 0 to 10, if 0 is selected the search is not performed in ASF).

Data Space Login - USERNAME

Username of Copernicus Data Space credentials. This field is optional only if the ASF login is inserted.

Data Space Login - USERNAME

Password of Copernicus Data Space credentials. This field is optional only if the ASF login is inserted.

Copernicus Data Space concurrent download

Maximum number of simultaneous performed download (available download from 0 to 2, if 0 is selected the search is not performed in Copernicus Data Space).

Parameters - Global

It brings to the general section of the Preferences parameters. Any modified value will be used and stored for further processing sessions.

Parameters - Multidownloader Accounts

ASF Login - USERNAME

Username of Alaska Satellite Facility credentials. This field is optional only if the Copernicus Data Space login is inserted.

ASF Login - PASSWORD

Password of Alaska Satellite Facility login credentials. This field is optional only if the Copernicus Data Space login is inserted.

ASF concurrent download

Maximum number of simultaneous performed download (available download from 0 to 10, if 0 is selected the search is not performed in ASF).

Data Space Login - USERNAME

Username of Copernicus Data Space credentials. This field is optional only if the ASF login is inserted.

Data Space Login - USERNAME

Password of Copernicus Data Space credentials. This field is optional only if the ASF login is inserted.

Data Space concurrent download

Maximum number of simultaneous performed download (available download from 0 to 2, if 0 is selected the search is not performed in Copernicus Data Space).

Parameters - Multidownloader Service

ASF Base URL

It allows setting the Downloader web API entry point to perform queries (https://search.asf.alaska.edu).

ASF Search URL

Subdirectory appended to the base_url address for performing search operations.

ASF Data URL

Parameter list for performing data downloading operations.

ASF Connection timeout

The number of seconds the Multidownloader will wait on ASF before considering a pending connection failed.

ASF Download timeout

The number of seconds the Multidownloader will wait on ASF to download at least the number of bytes specified in the download_speed field before considering a pending download failed.

ASF Download Speed

A threshold value, in byte, of data that must be downloaded from ASF within the specified download time out, otherwise the connection is considered lost and an error is triggered.

Data Space Base URL

It allows setting the Downloader web API entry point to perform queries (http://catalogue.dataspace.copernicus.eu/resto/api/collections/).

Data Space Search URL

Subdirectory appended to the base_url address for performing search operations.

Data Space Data URL

Parameter list for performing data downloading operations.

Data Space Connection timeout

The number of seconds the Multidownloader will wait on Copernicus Data Space before considering a pending connection failed.

DataSpace Download timeout

The number of seconds the Multidownloader will wait on Copernicus Data Space to download at least the number of bytes specified in the download_speed field before considering a pending download failed.

DataSpace Download Speed

A threshold value, in byte, of data that must be downloaded from Copernicus Data Space within the specified download time out, otherwise the connection is considered lost and an error is triggered.

Parameters - Proxy Settings

Proxy - URL

The URL of the proxy to use for the requests. This field is optional.

Proxy - USERNAME

The username to use to connect to the proxy to use for the requests. This field is optional.

Proxy - Password

The password to use to connect to the proxy to use for the requests. This field is optional.

Parameters - Other Parameters

It brings to the general section of the Preferences parameters. Any modified value will be used and stored for further processing sessions.

Output Files

Progress File Name

Name of the progress file. All the files found will be downloaded in this directory. More information in the technical notes.

In case the Preview Mode is active, no SAR data is downloaded. Instead, following files will be created for each acquisition:

*.png

Quicklook image file of the acquisition.

*.kml

Kml file, which can be opened in Google Earth, ArcGIS Earth (or similar). This file contains a footprint polygon and will drape the *.png image

*.dat (with .hdr)

Image quicklook file and corresponding hdr file readable in any GIS software.

Unzip files to this directory

All the downloaded files are unzipped in this directory.

General Functions

Exec

The processing step is executed.

Store Batch

The processing step is stored in the batch list. The Batch Browser button allows to load the batch processing list.

The window will be closed.

Help

Specific help document section.

Specific Function(s)

None.

Import Data - Sentinel-1 Multidownloader

Import Data - Sentinel-1 Multidownloader