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PreviSat is a simple, fast and intuitive application that displays the position of artificial satellites. Its graphical interface is designed to meet the needs of the neophyte or experienced observer. Developed in C++/Qt, it can work on all platforms (Windows, Linux, MacOS) and makes fast and precise calculations.

PreviSat can calculate all passes of artificial satellites for any location in the world. So you can observe passes of the ISS (International Space Station) or Iridium flares, even if you live in a city.

Below you can find a description of the most significant features of PreviSat.

Main features

Daylight ISS pass

PreviSat has a real-time, a manual and a simulation mode. So you can observe the displacements of the satellites in real time, or you can display positions for any times. In the "Main" tab, the numerical position is given in different frames (terrestrial, horizontal, equatorial) and some characteristics are given depending on the satellite position (velocity, magnitude). We also give positions of the Sun and of the Moon.

The second tab gives cartesian position of the selected satellite and its osculating elements (or keplerian elements). It also calculates some parameters deriving from osculating elements, for example orbital period, apogee or perigee.

The third tab describes the TLE of the selected satellite and gives informations about brightness and dimensions of the satellite itself.

Predictions of passes

PreviSat calculates passes of artificial satellites for any location on Earth and it is possible to set many parameters (Sun maximum elevation, satellite minimum elevation...).

Iridium flares can be determinated very quickly for the given location, and we also give terrestrial coordinates of the location next to your place of observation where the flare is maximum. An Iridium flare can reach a magnitude of -8, which is 30 to 40 times brighter than Venus.

Three other predictions are provided by PreviSat : the calculation of orbital events, the determination of ISS transits with the Sun and/or the Moon and the calculation of MetOp and COSMO-SkyMed flares.

All prediction algorithms are refined to provide precise results in a minimum of time. Compared to other similar softwares, PreviSat is widely more efficient.

TLE tools

Two tools are developed to manage TLE orbital elements. The first one allows to update categories of orbital elements from the Internet. The second tool is able to create a TLE file from another by specifying limiting values for orbital elements.

Management of location and options for display

PreviSat provides several categories of locations. You can easily add or delete a location or a category. A category is specially created in order to manage personal locations frequently used.

In the options tab, you can choose to display or to hide the most of elements drawn on the maps at your convenience.

Supported Files

The common text file extension for a TLE is "txt", but one can find a "tle" extension. PreviSat is able to read files with a "txt" or "tle" extension. The web site provides TLEs compressed with the "gz" format. PreviSat is also able to read this format.