Very few Sentinel 1B data

I am trying to access Sentinel 1 data from Google Earth Engine. For my study area which is a part of the Himalayan region I am getting only few data from Sentinel 1B for the year 2019 and I am not getting any data from 1B for the year 2018. Shouldn’t we be getting equal number of data from both 1A and 1B.
It would be really helpful if some one could explain the reason behind it.

For the year 2019:
List of platform number:
Object (2 properties)

As you can see there are only 11 images from 1B for a whole year in my study region.

Here is the link to the code:

Searching the original data on Scihub also returns the same results.

I don’t have the definitive answer to this, but I believe the scenes acquired by S1A and S1B is dependent on Sentinel 1 pre-defined mission observation scenario. You can check the KML files (archive and current) of the planned acquisitions provided here. Simply open the KML file in google earth pro and search for your location.

Also note that Sentinel 1B data have not been available after 23 December 2021, see news

I hope that helps