TerraSync software running v5.86 on Microsoft Desktop or Windows Tablet will be unable to select a coordinate system other than Lat/Long WGS 1984 as it's coordinate system. In order to get around this it is recommended that the user either ...
Visit the rental story map to get all the basics on collecting data, navigating, and transferring data using TerraSync and Pathfinder Office. https://storymaps.arcgis.com/stories/6400358a8a3b4fa99a350b119cd903f2
The attached support note demonstrates the workflow for using Pathfinder Office to post process Positions and GPScorrect ssf files and apply the corrections to the axf file.