PreviSat (may be the successor of TLE Analyser) is a free, open-source and multi-functional satellite real-time tracking software for Windows, Mac and Linux platforms, developed by astropedia from France. By analyzing the Two-Line Element (TLE) data published and updated regularly by United States Space Surveillance Network (SSN), it can achieve accurate prediction and tracking of satellite orbit, and simultaneously analyze the TLE parameters of hundreds of in-orbit targets.