Types of Satellites In Remote Sensing: Exploring Different Orbits and Functions

Satellites have become a critical component of modern technology and have revolutionized the way we interact with the world. From communication to navigation, from weather forecasting to environmental monitoring, satellites play a vital role in various applications. Among the many uses of satellites, remote sensing stands out as a prominent one. In this article, we will explore the different types of satellites in remote sensing based on their orbits and functions.

Satellites used in remote sensing can be classified based on their orbits and functions. The different types of orbits used in remote sensing are LEO, MEO, GEO, SSO, and GTO. The different types of satellites used in remote sensing based on their functions are communication, earth observation, navigation, and astronomical satellites.

Why Are There So Many Types of Satellites?

There are so many types of satellites because they serve a wide range of purposes and applications, including communication, navigation, Earth observation, weather forecasting, space exploration, scientific research, and military purposes.

Different types of satellites are designed and built to fulfill these specific functions, with varying sizes, orbits, frequencies, and technology. The diversity of satellite types allows for better coverage, higher efficiency, and more accurate results in their respective domains.

Types of Satellites In Remote Sensing by Orbit

There are various orbits in which satellites are placed, depending on their intended purpose and mission requirements. Here, we delve into the 5 most common types of orbits for remote sensing satellites:

Low Earth Orbit (LEO) Satellites

LEO satellites are positioned at altitudes between 160 and 2,000 kilometers (99 to 1,243 miles) above Earth. They typically complete an orbit in approximately 90 to 120 minutes, enabling them to provide frequent coverage over a specific area. Some key features of LEO satellites include:

• High-resolution imagery
• Rapid revisit times
• Reduced communication latency
• Shorter life span due to atmospheric drag

Applications of LEO satellites include weather monitoring, disaster management, and military reconnaissance.

Some examples of LEO satellites used in remote sensing are Landsat, Sentinel, and Aqua.

Medium Earth Orbit (MEO) Satellites

MEO satellites are positioned at altitudes between 2,000 and 35,786 kilometers (1,243 to 22,236 miles) above Earth. These satellites have an orbital period ranging from 2 to 24 hours. Characteristics of MEO satellites include:

• Medium-resolution imagery
• Larger coverage area compared to LEO satellites
• Longer life span than LEO satellites
• Moderate communication latency

MEO satellites are primarily used for navigation and communication purposes.

Some examples of MEO satellites used in remote sensing are GPS, GLONASS, and Galileo.

Geostationary Orbit (GEO) Satellites

GEO satellites are positioned at an altitude of approximately 35,786 kilometers (22,236 miles) above Earth. They have an orbital period of 24 hours, which allows them to remain stationary relative to a specific location on Earth’s surface. Key features of GEO satellites are:

• Continuous coverage over a fixed geographical area
• Lower resolution imagery compared to LEO and MEO satellites
• High communication latency
• Long life span

Some examples of GEO satellites used in communication are Intelsat, SES, and Eutelsat.

Sun-Synchronous Orbit (SSO) Satellites

SSO satellites have a unique orbit, which enables them to pass over the same location on Earth at the same local solar time on each orbit. SSO satellites are typically positioned at altitudes between 600 and 800 kilometers (373 to 497 miles). Features of SSO satellites include:

• Consistent illumination conditions for imaging
• Frequent revisit times
• High-resolution imagery
• Ideal for monitoring polar regions

SSO satellites are primarily used for Earth observation, including monitoring land use, vegetation, and ice sheets.

Some examples of SSO satellites used in remote sensing are MODIS, ASTER, and Landsat.

Geostationary Transfer Orbit (GTO) Satellites

GTO is an elliptical orbit used as an intermediate step for satellites transitioning from a low Earth orbit to a geostationary orbit. GTO satellites have the following characteristics:

• Highly elliptical orbit with an apogee close to GEO altitude
• Short-term use during satellite transition
• Primarily used for communication satellites

Some examples of GTO satellites used in communication are the Inmarsat fleet, and the EchoStar fleet.

READ MORE: Difference Between Geostationary and Geosynchronous Orbit

Types of Satellites In Remote Sensing by Functions

Satellites can also be classified based on their functions. There are four main types of satellites used in remote sensing applications based on their functions, as follows:

Communication Satellites

Communication satellites are designed to transmit and receive signals, such as voice, data, and video, between ground stations and other communication devices.

Communication satellites are commonly used for television broadcasting, internet connectivity, telephone networks, and military communication. In remote sensing, communication satellites are used to transmit data acquired by other types of remote sensing satellites to the ground stations.

Examples of communication satellite systems include the Globalstar, Iridium, and Intelsat networks.

Earth Observation Satellites

Earth observation satellites are designed to acquire data about the earth’s surface and atmosphere.

The data acquired by earth observation satellites can be used for various applications, such as land cover mapping, vegetation monitoring, oceanography, disaster management, and weather forecasting. Earth observation satellites use various sensors, such as optical, radar, and thermal sensors, to acquire data.

Examples of Earth observation satellite missions include Landsat, Copernicus Sentinel, and MODIS.

Navigation Satellites

Navigation satellites are designed to provide accurate location information to users on the ground.

Navigation satellites use signals transmitted by the satellites to determine the user’s location. Navigation satellites are commonly used in GPS systems, which are used for various applications, such as navigation, surveying, and mapping.

Examples of navigation satellite systems include the Global Positioning System (GPS), GLONASS, and Galileo.

Astronomical Satellites

Astronomical satellites are designed to study objects beyond the earth’s atmosphere, such as stars, planets, and galaxies.

Astronomical satellites are equipped with specialized sensors, such as telescopes, to observe and study these objects. Astronomical satellites are used to study various phenomena, such as the formation of galaxies, the evolution of stars, and the search for extraterrestrial life.

Examples of astronomical satellite missions include the Hubble Space Telescope, Chandra X-ray Observatory, and James Webb Space Telescope.

Conclusion: Different Types of Satellites In Remote Sensing

In conclusion, satellites have revolutionized the way we interact with the world, and remote sensing is one of the prominent applications of satellites. Satellites used in remote sensing can be classified based on their orbits and functions.

The different types of orbits used in remote sensing are LEO, MEO, GEO, SSO, and GTO, each with its advantages and disadvantages.

The different types of satellites used in remote sensing based on their functions are communication satellites, earth observation satellites, navigation satellites, and astronomical satellites.

Each type of satellite plays a critical role in various applications and has contributed significantly to our understanding of the world.

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