Two-Line Elements (TLE)

Two-line elements is a standardised format used to describe the orbit of a satellite. They consist of a set of data that includes important orbital parameters, such as the satellite’s position, velocity, and other relevant information at a specific epoch or time.

The TLE format was developed to provide a compact and standardised way to convey essential orbital data for tracking and predicting the motion of satellites. It is widely used by various organisations, including satellite operators, space agencies, and tracking networks.

A typical TLE consists of two lines of text. The first line, known as the “line 1,” provides information such as the satellite’s name or identification number, the International Designator, the epoch time (the specific time at which the orbital parameters are valid), and certain orbital elements like the inclination, right ascension of the ascending node, and eccentricity.

The second line, known as the “line 2,” includes additional orbital parameters like the argument of perigee, mean anomaly, mean motion, and revolution number. These parameters, along with the data from the first line, allow for precise calculation of the satellite’s position and velocity at any given time.

TLE data is generated based on observations from ground-based tracking stations, radar systems, or other tracking methods. These observations are processed to determine the satellite’s orbital elements, which are then encoded into the TLE format. It’s important to note that TLE data is time-sensitive and needs to be regularly updated to account for orbital perturbations and changes in the satellite’s orbit.