ERDAS IMAGINE 2018 Update 1 (v16.5.1), to be released in the June/July, 2018 timeframe, will address the following issue (IM-12386 / 00026796):
Customers have reported that when using ERDAS IMAGINE 2016, the StereoSAR DEM tool no longer produces acceptable output DEMs compared to previous versions.
The problem was inadvertently introduced via a change to the way coordinates are referenced in "raw" satellite imagery which was not taken into account in the StereoSAR DEM tool. This meant that control points were not being correctly related to their image position.
The solution was to correct StereoSAR DEM to use the newer coordinate referencing system.
This change will be made available to all customers as part of ERDAS IMAGINE 2018 Update 1.