The Level-0 data contains the Azimuth Beam Address for every pulse collected. It is defined in Sentinel-1-SAR-Space-Packet-Protocol-Data-Unit.pdf in section 3.2.5.13.1.4 Azimuth Beam Address. The document indicates that this field “identifies one of 1024 available Azimuth beams”. Where can I find the look-up table or conversion from Address/Index value to degrees or radians?
Based on examining the burst time, the azimuth steering rate, and the actual used span of azimuth beam addresses, I believe the full span of the azimuth steering to cover +/-0.018 radians (i.e. - when the azimuth beam address is 0, the electronically steerable antenna is pointing -0.018 radians in azimuth, when the azimuth beam address is 512, the elcetronically steerable antenna is pointing 0 radians in azimuth (‘broadside’), and when the azimuth beam address is 1023, the electronically steerable antenna is pointing +0.018 radians in azimuth).