Comparison of three tracking methods-Program Tracking, TLE Tracking, and Vector Tracking

In satellite communications, Program Tracking, TLE Tracking, and Vector Tracking are three distinct tracking methods, each with different principles and application scenarios. Although they are all used to control ground station antennas to point toward satellites, their implementation methods and accuracy levels differ significantly. With the development of satellite communication industry, TLE Tracking, and Vector Tracking are becoming more and more widely used due to their own advantages.
1. Program Tracking
Program Tracking is a method based on pre-programmed satellite orbital data. The ground station calculates the satellite’s position in advance using known orbital parameters (such as Keplerian elements or TLE data) and generates a schedule of azimuth and elevation angles over time. The ground station then adjusts the antenna pointing according to this schedule.
2. TLE Tracking
Two-Line Element (TLE) tracking is a widely used method for predicting the position and velocity of Earth-orbiting satellites. TLE data is provided by organizations like NORAD (North American Aerospace Defense Command) and is used in satellite communication systems to determine the location of satellites for tracking, communication, and data transmission purposes.

A TLE is a data format used to convey the orbital elements of an Earth-orbiting object, such as a satellite. It consists of two lines of 69 characters each, containing information about the satellite’s orbit. These elements are used in conjunction with an orbital prediction model (such as SGP4/SDP4) to calculate the satellite’s position and velocity at a given time.
3. Vector Tracking
Vector tracking is an advanced signal processing technique used in satellite communication systems, particularly in Global Navigation Satellite Systems (GNSS) receivers. Unlike traditional scalar tracking, which processes each satellite signal independently, vector tracking employs a unified approach to estimate the user’s position, velocity, and time (PVT) by jointly processing all available satellite signals. This method offers several advantages, including improved robustness, accuracy, and performance in challenging environments.
4. Comparison of the Three Tracking Methods

Monopulse tracking

This tracking system requires a special feed system on the antenna with multiple outputs, arranged so that the phase angle difference between the beacon signal appearing at the various outlets relates to the angle that the satellite is off from the central main beam direction.

Advantage and disadvantages
Fast and immediate closed loop following of the satellite.
Good for fast moving satellites.
Good for mobile satellite operation, such as maritime, aircraft or land vehicles.
Requires multiple receivers.

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