1. Leo Low Earth Orbit Distance
2. Leo Low Earth Orbit Day
3. Leo Low Earth Orbit
4. Satellite Low Earth Orbit (leo)

This circular obits are used by the vast majority of satellites. They are low in altitude (between 200 and 3.000 km above the Earth’s surface).

LEO basics

• Orbit times are much less. The lower altitude means higher velocities are required to balance the earth’s gravitational field.
• The satellite and user are closer together and therefore path losses are lower.
• The round trip time (RTT) for the radio signals is lower.
• Radiation levels are lower.
• Less energy is expended placing the satellites in LEO.
• Speed reduction occurs as a result of friction from the atmosphere.

Applications for LEO satellites

A variety of different types of satellite use the LEO orbit levels:

Launched into Low Earth Orbit—512 miles Orbits Earth 14 times pole-to-pole with SNPP 14x Images entire globe twice a day 2x State of the art instrumentation to collect data on Earth’s atmosphere, lands, and oceans Sends more than 2,000 gigabytes of data to Earth every day NOAA-20: Today’s Prime Operational Satellite NOAA-20 (previously. Low Earth Orbit (LEO) Satellites are in orbit at altitudes between 500 to 2,000 kilometres. For complete Earth coverage and due to their limited (momentary) Field of View (FoV) a high number of satellites are required. Unlike GEO satellites which are stationary relative to the Earth’s rotation; LEO satellites at 1000Km altitude have an orbital velocity relative to the Earth of about 7.3Km/s.

• Communications satellites – Iridium phone system.
• Earth monitoring satellites –
• The International Space Station

Limited field of view of the earth´s Surface: there must be a big number of satellites in order to have a network with wide coverage and organize them to form constellations.

The five Big LEO are Iridium, Global Star, Odyssey, ICO Global Communications, Teledesic.

LEO Orbits: Circular (polar or inclined) and elliptic.

Basics parameters:

• Circular Orbits
• Eccentricity = 0 (e=0º)
• The earth is circular with radius 6377 km
• The semimajor axis of the orbit (the radio) is a and the instantaneous height is h.

The linear and angular velocity of the satellite are:

k: Kepler constant

The orbital period of the satellite is:

Leo Low Earth Orbit Distance

Applying the sines law we can obtain the central angle at the edge of coverage as a function of the mínimum elevation angle(El):

The distance d from the edge of coverage to the satellite will be:

The minimum elevation angle is an important feature of the system. Is the angle at which the terminal at the coverage edge sees the satellite. Determines the availability of the link and should be considered for handover.

Design of a LEO system lay on a compromise between number of satellites, delay and losses.

The area of ​​the sphere skullcap is:

Therefore the minimum number of satellites required in function of the central angle, which in turn is a function of elevation and the height of the orbit:

Leo Low Earth Orbit Day

Elements:

• Satellites (main nodes of the network,transmission and switching devices).
• Earth Gateways: Earth Stations (switching and network management, access to public terrestrial networks).
• User terminals (fix or mobile).
• Links: mobile users (satellite-terminal), gateway (sat-gw) between satellites (ISL).

Low Earth Orbit satellites circle the earth at a distance of about 1000km, your typical satellites are either Geostationary Earth Orbit (GEO) satellites located at a distance of 36,000km or your mid range satellites MEO located at about 8,000km. Being closer to the earth has its benefits as the latency delay will drop, that is the time it takes for your data to complete a round trip (RTT), going from earth to satellite and back again. The GEO latency is of 600 milliseconds, MEO of 180ms and LEO of 40ms, the new LEO satellite “Constellation” will allow you to access noticeably faster response times that are important for various applications such as Internet browsing, messenger or online chats, Voice over IP (VoIP), gaming, and an essential part if you are conducting High Frequency Trading (HFT).

Who will provide this?

Leo Low Earth Orbit

In 2022 our partner Telesat will enter commercial operations to deploy hundreds of LEO’s. These will form a mesh like pattern that will ensure all regions across the globe are covered, including polar regions. This constellation of satellites will allow OmniAccess to give our customers full global coverage, whilst at the same time ensuring the highest VSAT throughput and low latency.

Rather than having to follow one geostationary satellite, yachts will be able to follow various satellite beams simultaneously. These satellites will be significantly closer to earth, reducing the latency of the signal, and their capacity to link between provides redundancy to guarantee the service.

What should I, as a client, take into consideration?

Existing Antennas may need to be replaced or updated, but here the specifications are not clear yet and these replacement could be timed in-line with service expectancy.

Satellite Low Earth Orbit (leo)

At Omniaccess we are already looking into flexible solutions for our clients to make the transition as smooth as possible. In any case, we expect the return on switching to LEO to massively outweigh the possible investments required and will provide periodic updates for our clients as soon as further details are made available.