Issues with Seamless SAR Archive (SSARA) query in tutorial notebooks

[manudeo]

Dear fellow ISCE2 learners,

Like me, if you are using the tutorials from isce2-docs/Notebooks/UNAVCO_2020/, you might run into an issue while working with the SSARA queries for data downloads Juputer Notebook - https://github.com/isce-framework/isce2-docs/blob/master/Notebooks/UNAVCO_2020/DataAccess/SSARA.ipynb

The GitHub link in the code at cell 2 !git clone https://github.com/bakerunavco/SSARA.git $HOME/work/SSARA is dead. Replacing that link with https://www.unavco.org/gitlab/unavco_public/ssara_client.git works.

Another issue is - the Sentinel-1 orbit download link has changed and the query to download one (in topsApp notebook) will result in an error. The workaround is to rectify the ssara_federated_query.py file. Follow the instructions given at this link (thanks to Rebecca Bussard) - https://www.unavco.org/gitlab/unavco_public/ssara_client/-/issues/3

I am also copypasting the solution here:

Sentinel Orbits with SSARA

Currently, the script ssara_federated_query.py is calling a broken link to try to grab orbit files for Sentinel-1 and the format that it’s using to call the files doesn’t match the current file format. To fix this, the following changes can be done:

Line 315:

scene_center_time = datetime.datetime.strptime(scene['startTime'],"%Y-%m-%d %H:%M:%S")

needs to be changed to

scene_center_time = datetime.datetime.strptime(scene['startTime'],"%Y-%m-%dT%H:%M:%S.000000")

Line 323:

BASE_URL = 'https://qc.sentinel1.eo.esa.int/%s/?validity_start_time=%s' % (orb_type, validity_start_time.strftime("%Y-%m-%d"))

needs to be changed to

BASE_URL = 'https://s1qc.asf.alaska.edu/%s/?validity_start_time=%s' % (orb_type, validity_start_time.strftime("%Y-%m-%d"))

Changing the location of where to get the orbit files to ASF requires an ASF username and password to be used and for those credentials to be included in the script somehow. There are definitely more sophisticated methods of doing this, but for a simple and easy fix, the following works:

Line 334:

cmd = "wget --no-check-certificate -c %s" % orbit_file_url

needs to be changed to

cmd = "wget --user=ASFusername --password=ASFpassword %s" % orbit_file_url

This requires users to go edit this line in the ssara_federated_query script when they download it and enter their own username and password. As stated before there is probably another way to read in password_config.py but this is another method that works and could be used for the time being.

I hope this will help some of you.

Best,
Manu