Data can be imported from UWP data files which are in the following format. This format seems to be common for Traveller map data that I've managed to find on the web.
1-14: Name
15-18: HexNbr
20-28: UWP - Port, Size, Atmosphere, Hydro, Pop, Gov, Law (-) Tech
31: Bases
33-47: Codes & Comments
49: Zone
52-54: PBG - Population digit, number of other terrestrial worlds, number of gas giants
56-57: Allegiance
59-74: Stellar Data
0 1 2 3 4 5 6 7 8
012345678901234567890123456789012345678901234567890123456789012345678901234567890
eC Mirriam 0303 B9998A6-A B A 514 Im M6 V
012345678
Saregon 2936 A584976-E Hi 114 Im M3 V M6 D
2937 B434779-A A 703 Im M1 III M9 V
Shakiiga 2938 B867ACA-B Hi 710 Im K4 V
It is normally expected that all star systems for a single sector will be stored in a single file. Such files may have further information about sub sector names etc, which will be detailed later.
Traveller data only details the main world of a system (actually, the extended data format above does include a count of the number of other planets, but no detail on them). For this reason we guess the rest of the information about the system, and basically just make it all up.
A system is considered to have a Main World, which is the most important world in the system. The Main World is the one with the largest starport, followed by largest population.
After generating a random star system, the world most likely to support life is replaced with one created from the UWP data. In theory, this could be a moon, but the software doesn't yet support this.