SNAP-PYTHON API Finding Particulars

Currently, I am working on a project of detecting ocean objects using Sentinel-1 data. I am using Doppler frequency analysis to analyze shift of such targets due to relative velocity of Sentinel 1 satellite and target(ship or vessel). So I need to work on a formula. For this formula, I need to know following things -

  1. Altitude of Satellite (SAR) for given image.
  2. Incident angle when SAR is looking at particular target (given pixel coordinates of target)
  3. Satellite to target slant range (in meters)
  4. Azimuth line heading with respect to north direction

As such number of such targets are larger and I am coding in python, it is best for me to go with SNAP-python API. But I went through API documentation and it is difficult to find require details. It would be appreciated if anyone could help me with this code.