File → Open .pl5, or the Open .pl5 button on the toolbar, reads a Pathloss 5 file. If the open project already has path data, Spanline asks whether to merge the file into it or replace the project. Cancel leaves the project as it was.
After the read, Spanline lists what it took from the file. The profile stored in the .pl5 is the one on screen until elevations are fetched from USGS. A length recomputed with Vincenty is shown next to the length stored in the file, and a difference larger than 1 m is flagged.
A hop created in Spanline starts horizontal. The Austin North demo hop stays vertical, because that one is set on purpose.
Export .pl5 writes a Pathloss 5 file from the open hop. The control stays disabled until the project has a site. The tooltip then states that sites and a hop are required.
College & Bethel is the Byhalia path used as a check. After that file is imported, the thermal fade margin is 17.28 dB and the receive level is −31.32 dBm. The method page records the constants behind that result.