S-1 TOPS SPLIT Analyzer (STSA)

This code intends to help users easily work with the S-1 TOPS SPLIT function in SNAP software by parsing the XML metadata of Sentinel-1 satellite data and converting it into usable data such as shapefiles or webmaps.

Using S-1 TOPS SPLIT Analyzer you are able to:

• Download XML data directly from Copernicus Scihub and view TOPS-SPLIT data. No need to download the full 4 GB image to view the TOPS SPLIT data
• View TOPS-SPLIT data from downloaded ZIP files containing full size Sentinel-1 imagery
• View all subswaths at the same time
• Save S1-TOPS-SPLIT data as a shapefile, JSON, or CSV
• View and interact with S1-TOPS-SPLIT data using a webmap. In addition, you can add a polygon to visualize its extent with regards to the S1-TOPS-SPLIT data

Comments and feedback are welcome.

Live Web App

For easier usage. STSA has a web app which is hosted by Streamlit. Access it here! You can view data and download it in GeoJSON format.

Installation

This has been tested to work in Python versions 3.8 to 3.9

If you are using Windows you need to manually install the GDAL and Fiona wheels OR install Fiona using Anaconda:

conda install -c conda-forge fiona

Linux or MacOS users can disregard the previous instruction. Install stsa into your environment by typing this command:

pip install git+https://github.com/pbrotoisworo/s1-tops-split-analyzer.git

Usage

STSA can be used in the command line and as a Python import.

Command Line

CLI access is available if you directly run stsa.py. The available flags are:

Flag	Description
-v	Print all statements
--zip	Path of Sentinel-1 ZIP file
--safe	Path of Sentinel-1 manifest.safe file
--swaths	List of target subswaths
--polar	Polarization
--shp	Path of output shapefile
--csv	Path of output CSV file
--json	Path of output JSON file
--api-user	Copernicus username
--api-password	Copernicus password (Leave empty for secure input)
--api-scene	Sentinel-1 scene ID to download
--api-folder	Folder for downloaded XML files

Below is a sample command where user selects subswath IW2 and IW3, specifies VV polarization, and specifies output data.

python stsa.py --zip S1_image.zip --swaths iw2 iw3 --polar vv --shp out_shp.shp --csv out_csv.csv --json out_json.json

Python Import

Below are code samples of using TopsSplitAnalyzer. When loading Sentinel-1 data please choose either API or ZIP method only.

############################################
# Load data using `load_api` or `load_zip`
############################################

import stsa

s1 = stsa.TopsSplitAnalyzer(target_subswaths=['iw1', 'iw2', 'iw3'], polarization='vh')

# METHOD 1: Load using local ZIP file
s1.load_zip(zip_path='S1_image.zip')

# METHOD 2: Load using Copernicus Scihub API
s1.load_api(
    'myusername',
    'S1A_IW_SLC__1SDV_20210627T043102_20210627T043130_038521_048BB9_DA44',
    'mypassword'
)

##################################################################
# Export the data in your preferred format.
# To visualize on a webmap you need to be using Jupyter Notebook.
##################################################################

# Write to shapefile
s1.to_shapefile('data.shp')

# Get JSON
s1.to_json('json_output.json')

# Write to CSV
s1.to_csv('output.csv')

# Visualize on a webmap with additional polygon
s1.visualize_webmap(polygon='mask.shp')

Output shown on a webmap

Tests

If you plan on contributing ensure that is passes all tests by installing pytest and typing this in the project directory:

pytest tests