Satellite 101 Series Part III: Deciphering the Acronyms: The Satellite Breakdown
Like any field, the satellite communications industry has its own set of commonly used acronyms. Unfortunately, it’s easy to get lost among the stars—or among the LEOs, GEOs and MEOs. We want to make it easy and break down the letters and highlight the ones you really need to know.
It’s All About Orbits
If you’re just getting started, you want to know the basics. What satellite acronyms are going to get you through your next dinner party? There are three that provide a good starting place: GEO, MEO and LEO. These acronyms refer to the specific orbits that a satellite is in, each with its own characteristics.
LEO, or Low Earth Orbit satellites are the closest to Earth and orbit roughly 400 to 1,000 miles above the planet. Due to their close proximity, LEO satellites have better signal strength and shorter time delay (or latency) than other satellites. However, you need more of them to cover the planet since their coverage footprint is the smallest. Typically, LEO satellites are only visible on the horizon for 3 to 15 minutes meaning you would switch to a new satellite up to 480 times in a 24-hour period to maintain connectivity. This is why it’s necessary to launch a lot of them in a constellation, and why it’s important to move towards electronically-steered antennas. Mechanical antennas just aren’t fast enough to track these satellites, especially when you’re on the move. Not to mention all of the mechanical parts risk more frequent failure with such constant movement.
The future of LEO satellites is exciting. The majority of LEO satellites currently in orbit are used for Earth monitoring, and the emergence of communications satellites is the next frontier.
MEO, or Medium Earth Orbit satellites are at a higher altitude than LEO satellites. MEOs orbit somewhere between 5,000 and 10,000 miles above the Earth’s surface. They have a longer time delay than LEO satellites, but are visible on the horizon for longer periods compared to their LEO counterparts – usually between two to eight hours. Many of our current communications satellites, including GPS satellites, can be found in MEO.
GEO, or Geostationary Orbit satellites are the slow-moving, easy-to-maintain satellites that are cruising around the planet 22,284 miles above us. They orbit the Earth at approximately the same speed as the Earth rotates, keeping them in roughly the same position all the times. A single GEO satellite can cover up to a fourth of the Earth’s surface.
GEO satellites really revolutionized communications in the 1970s by providing satellite service to rural areas, and sparking competition in the television broadcasting industry. They are low maintenance satellites that are still used today for satellite radio and television.
So which one is best?
Each satellite serves a different purpose. At Kymeta we are excited for the progression of LEO and MEO constellations, and their impact on the future of connectivity.