Help Content > Import Data > Download > Capella Archive Download

Purpose

This tool allows one to perform a query and download of Capella data from the Capella Space website archive - (https://www.capellaspace.com/).

Please note: Capella images are available for download provided a payment, sarmap SA only provides this tool to ease the search and download of archived images. Sarmap SA will not respond regarding wrong purchases or unexpected additional costs.

The purchase for the whole order is finalized when the download of the first image starts. Therefore interrupting a download in progress will result in the payment of not yet downloaded images as well.

Technical Note

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

When started from the SARscape graphical user interface (under Import Data->Capella Archive Download), the downloader is executed as a stand-alone, detached window. In this way, the downloading process does not depend on ENVIQGIS: you can even close ENVI QGIS 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. When a second request is preformed using the Capella Archive 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 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!

Please note: According to the connection speed, area size and data extension the download of a single image can take up to several hours.

Preview Mode

The download of preview images does not result in any cost.

Small previews will be downloaded in the output folder instead of the full size SAR data. Note: 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. 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

White other

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. All acquisitions inside or intersecting this polygon are returned. The shapefile must be in GEO-GLOBAL cartographic system.

Parameters - Principal Parameters

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).

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.

Preview Only

With this flag on, the Capella Archive Download is entering in Preview Mode. More information in the technical note.

Orbit Direction

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

Product Type

Filter for product type (SLC, GEC, GEO, SICD, SIDD, CPHD, ALL). If the type ''ALL'' is selected, the tool will download all the product types at the cost of one product.

This parameter is optional.

Polarization Mode

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

Wait For Confirmation

When this flag is set to true the process will display a preview of the total order`s cost and wait for confirmation before proceeding.

Wait For Completion

It allows to close the panel ones the process is completed.

Repositories

It allows to input a list of folders (separated by ;), the Capella Downloader will search file matching the query in those folders before downloading it. If a file is found it will be removed from the order and not downloaded again. In this case the file won’t be downloaded from the server, saving time and possibly reducing the order`s total cost. (C:\download_repo_1\; D:\download_repo_2\;...)

Capella Login - USERNAME

Username of Capella Space login credentials. This field is mandatory.

Capella Login - PASSWORD

Password of Capella Space login credentials. This field is mandatory.

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 - Capella Account

Capella Login - USERNAME

Username of Capella Space login credentials. This field is mandatory.

Capella Login - PASSWORD

Password of Capella Space login credentials. This field is mandatory.

Parameters - Capella Service

Capella Base URL

It allows setting the Downloader web API entry point to perform queries (https://api.capellaspace.com).

Capella Search URL

Subdirectory appended to the base_url address for performing search operations.

Capella Token URL

Subdirectory appended to the base_url address to acquire the login token.

Capella Review URL

Subdirectory appended to the base_url address to request the order preview before finalizing it (E.G. displaying the cost).

Capella Order URL

Subdirectory appended to the base_url address to finalize the order.

Capella Connection timeout

The number of seconds the Capella Archive Download will wait before considering a pending connection failed.

Capella Download timeout

The number of seconds the Capella Archive Download will wait to download at least the number of bytes specified in the download_speed field before considering a pending download failed.

Capella Download Speed

A threshold value, in byte, of data that must be downloaded 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, the 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.

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.

Add Results to View

Tick this box if results have to be displayed.

Specific Function(s)

None.

References

None.