This inclined orbit satellite tracking system is iSat’s innovation project. Although still in development, we have a working model and expect to release the product in Q1 of 2019.
It’s tracking performance will compete with currently available inclined orbit tracking solutions but at a significantly lower cost.
Current inclined orbit satellite tracking methods
Step Track—This method constantly adjusts the antenna position to find the best receive level of a beacon signal. The problem with this method is that tracking movements are initiated by a drop in signal level. This means that the antenna is always following the satellite movements, not moving in unison. This results in fluctuations in received signal power at each end of the link. This method is also susceptible to interference which can cause loss of the tracked satellite completely. A step-track system requires a motorised antenna as well as a beacon receiver and antenna controller.
Monopulse Tracking – This method is significantly more accurate than the others. A beacon signal from the satellite is received by two separate elements within the antenna feed simultaneously. A comparison of the signal at the 2 different reception points accurately predicts the location of the satellite. The antenna can then track the satellite in real time rather than waiting for the signal to drop. However, it requires more complex equipment and therefore greater expense. This method requires a motorised antenna, a complex control system and a specialist feed. This method is usually only implemented in large hub antennas due to the cost and complexity.
External positional data tracking—More recently, a new tracking solution has emerged which uses positional data from an external source. There are organisations which track all celestial bodies and provide positional data free online . An antenna can then use the data to track the required satellite by knowing exactly where it is and exactly where it will be at a given time. This eliminates two of the big drawbacks of beacon tracking (poor signal stability and susceptibility to interference/fading) although current solutions are still fairly expensive. This method requires a motorised antenna, and a tracking controller
Our method is an evolution of the external positional data tracking method. We keep the antenna reflector fixed and instead move the feed along a single axis of travel in order to steer the antenna beams in unison with the satellite. Add in some positional data and some clever maths and we now have a tracking solution which is far more accurate and reliable than the industry standard ‘step-track’ method and significantly cheaper than any other commercially available solution. You can also retro-fit this system to an existing fixed antenna, making the switch to inclined capacity quick and easy. This method requires a fixed axis antenna and our inclined orbit tracking system.