SLC georeferencing

Hello,

I am working with Sentinel-1 SLC data and I need SLC data to perform interferometry. I would like to identify the coordinate of given pixel. Currently, I am using the longitude and latitude tie-point-grid. The problem is that the values are wrong/offset by a given value due to the fact that SLC products are not map projected.

I would like to know how to get the projected coordinates of a given pixel (without terrain-correction of the image, I need to keep the slant range geometry). SNAP seems to do it when we product is plotted on map. (world map visualization)

My question is: What is the algorithm to get the map coordinates of a SLC pixel?

Thx

Apply Range Doppler Terrain Correction and select complex output to geocode your data while maintaining the complex information