A Detailed Report on the Advantages and Disadvantages of LEO and GEO

This report provides a comprehensive comparison of Low Earth Orbit (LEO) and Geostationary Orbit (GEO) satellites, examining their respective advantages and disadvantages. The analysis begins by highlighting the benefits of LEO, such as reduced delay times, full Earth coverage, and higher elevation angles, which make them suitable for applications where real-time communication and coverage in urban areas are critical. However, it also acknowledges a key disadvantage: the need for more satellites to provide continuous coverage. The report then shifts its focus to GEO, emphasizing its advantages, including wide geographical coverage, continuous visibility from a single point, and the elimination of ground station tracking requirements. It also addresses the drawbacks of GEO, such as significant signal travel delays, which make it unsuitable for time-sensitive applications, and limited coverage near the Polar Regions. The report references several sources to support its findings, providing a well-rounded overview of the topic.

Introduction to Space Studies
INTRODUCTION TO SPACE STUDIES
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Introduction to Space Studies
Advantages and Disadvantages of LEO
There are several advantages that are being offered by low earth orbit (LEO) as opposed to the
geostationary orbit. This particular benefit is however coupled with at least one main
disadvantage (Leanza et al.2019).
Delay: There is a budgeting at 125ms for one-way delay to GEO satellite. This implies that one-
way up and down will give a double or twice the original value of 250ms (Qu et al.2017). There
is about 0.5s round-trip delay. The delay to any typical LEO will be equivalent to 2.67ms with
the delay of round-trip being about 10.66ms. It is possible to relay calls from/to mobile users of
the same systems while utilizing the services of the conventional satellites. In other words, the
services of data do not have to undergo restriction of the utilization of “handshake” as well as
ARQ of stop-and –wait as it is common with the services of the system of GEO (Tscherne et
al.2018).
Full Earth Coverage and Higher Elevation Angles: It is important to note that GEO orbit
cannot provide coverage which goes beyond 80° latitude. Instead, it provides angle coverage
which is low as to many of the world’s centers of great population as a result of its comparatively
high latitude. This kind of dilemma is faced by the cities in Canada and Europe (Cucinotta 2015).
Satellites of LEO can provide elevation angle greater than 40 degree depending on the orbital
plane spacing. This kind of performance will be attractive particularly in those areas of urban
centers that have very tall buildings. This implies that availability of coverage will be restricted
to the southern side of such buildings which are in the Northern Hemisphere and with properly
defined shot to the horizon (Botella et al 2016).

Introduction to Space Studies
Advantages and disadvantages of GEO
The following are some of the advantages of GEO:
 Considering that it is at greater height, it is capable of covering very large geographical
areas. This implies that three satellites will effectively cover the entire Earth(Phipps &
Bonnal 2016).
 There is continuous 24 hours visibility of satellite from a single fixed point on the surface
of the Earth
 This particular orbiting system is ideal for both multi-point application and broadcasting.
 There is no need for ground station tracking since there is continuous visibility from the
Earth all the time from a location which is fixed(Boice 2019)..
 There is no need for the inter-satellite handoff
 There is need for very little number of satellites for covering the entire Earth.
 It is possible to use less complex receivers for communication in satellites since there is
no Doppler shift.
GEO has the following disadvantages
 The GEO signals will always require considerable amount of time for them to move from
satellite to Earth and vice versa. The travel delay of the signal is about 120ms which is in
one direction. There is provision of 120 ms latency with 3x108 m/sec speed of the signal
by the distance of 35786km. This makes it unsuitable for point to point applications
which are usually time sensitive like video (Boice 2017).

Introduction to Space Studies
 The orbit of GEO is located above the equator. This makes it very difficult to effectively
broadcast near the Polar Regions.
 At higher latitude places which are usually greater than 77 degrees, the coverage will be
definitely poor (Campa, Szocik & Braddock 2019).

Introduction to Space Studies
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Introduction to Space Studies
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