This looks like failed antenna pattern removal in one of the subswaths, probably the first subswath in near range. Does this image mostly cover an ocean? It needs to be corrected for by the data provider.
Yes! this image is taken over Actic Ocean…Is there no possible Remedy for that?
What is the acquisition?
HV band of dual pol of sentinel1 image
Which product exactly?
Looks like typical S-1 EW image over sea ice/ocean - high noise level in the near range EW1 sub-swath. You can do noise removal with SNAP, but it wont remove totally that wavy noise pattern in the azimuth direction.
see Radar-Radiometric - S-1 Thermal Noise Removal
This is improved with the IPF v2.9 products - we’re currently verifying the module update for SNAP that enables the proper handling of these new products.