Orbit
An orbit in a remote sensing satellite refers to the path that the satellite follows as it orbits the Earth. The type of orbit that a satellite follows can have a significant impact on its capabilities and the types of data it can collect.
Low Earth orbit (LEO) satellites are those that orbit the Earth at altitudes of around 160 to 2,000 kilometers (100 to 1,200 miles). These satellites orbit the Earth relatively quickly, completing one orbit in just a few hours. Because they are so close to the Earth, LEO satellites have a relatively high spatial resolution, meaning they can capture images of small features on the Earth’s surface. However, they also have a relatively narrow field of view and can only observe a small area at a time.
Medium Earth orbit (MEO) satellites are those that orbit the Earth at altitudes of around 8,000 to 12,000 kilometers (5,000 to 7,500 miles). These satellites have a broader field of view than LEO satellites and can observe a larger area at a time, but they have a lower spatial resolution because they are further away from the Earth.
Geostationary orbit (GEO) satellites are those that orbit the Earth at an altitude of around 36,000 kilometers (22,000 miles). These satellites orbit the Earth at the same rate that the Earth rotates, so they appear to be stationary in the sky. GEO satellites are often used for communication and weather forecasting because they can provide continuous coverage of a particular region. However, they have a very low spatial resolution because they are so far away from the Earth.
Sensor Characteristics and Applications of Weather Satellites: GOES, NOAA, METEOSAT, INSAT
GOES (Geostationary Operational Environmental Satellite):
- Characteristics: The GOES satellite is stationary and orbits the Earth at the same rate as the Earth’s rotation, allowing it to maintain a constant position relative to the surface. It is equipped with various sensors, including visible and infrared cameras, to measure temperature, humidity, and atmospheric pressure.
- Applications: The GOES satellite is used for weather forecasting and monitoring, particularly in the Americas. It is also used to track storms, such as hurricanes, and to monitor the Earth’s radiation budget.
NOAA (National Oceanic and Atmospheric Administration):
- Characteristics: The NOAA satellite is a polar orbiting satellite, meaning it orbits the Earth in a north-south direction. It is equipped with a range of sensors, including visible and infrared cameras, to measure temperature, humidity, and atmospheric pressure.
- Applications: The NOAA satellite is used for weather forecasting and monitoring, particularly in the United States. It is also used to track storms, such as hurricanes, and to monitor the Earth’s radiation budget.
METEOSAT (Meteorological Satellite):
- Characteristics: The METEOSAT satellite is a geostationary satellite, meaning it orbits the Earth at the same rate as the Earth’s rotation, allowing it to maintain a constant position relative to the surface. It is equipped with various sensors, including visible and infrared cameras, to measure temperature, humidity, and atmospheric pressure.
- Applications: The METEOSAT satellite is used for weather forecasting and monitoring, particularly in Europe and Africa. It is also used to track storms, such as hurricanes, and to monitor the Earth’s radiation budget.
INSAT (Indian National Satellite System):
- Characteristics: The INSAT satellite is a geostationary satellite, meaning it orbits the Earth at the same rate as the Earth’s rotation, allowing it to maintain a constant position relative to the surface. It is equipped with various sensors, including visible and infrared cameras, to measure temperature, humidity, and atmospheric pressure.
- Applications: The INSAT satellite is used for weather forecasting and monitoring, particularly in India and the surrounding region. It is also used to track storms, such as hurricanes, and to monitor the Earth’s radiation budget.
Land Observation Satellite: LANDSAT, SPOT, IRS, IKONOS, GEOEYE, WORLDVIEW, SENTINEL
Landsat:
The Landsat program is a series of Earth observation satellite missions jointly managed by NASA and the U.S. Geological Survey (USGS). The first Landsat satellite, Landsat 1, was launched in 1972 and the latest, Landsat 8, was launched in 2013. Landsat satellites are used to monitor the Earth’s surface and gather data on land use, land cover, natural resources, and environmental changes.
SPOT
The System for Observation of the Earth (SPOT) is a series of Earth observation satellites developed by the French space agency CNES and operated by Airbus Defense and Space. The first SPOT satellite, SPOT 1, was launched in 1986 and the latest, SPOT 7, was launched in 2014. SPOT satellites are used for a variety of applications, including mapping, land cover classification, and monitoring of natural disasters and environmental changes.
IRS:
The Indian Remote Sensing (IRS) satellites are a series of Earth observation satellites developed by the Indian Space Research Organisation (ISRO). The first IRS satellite, IRS-1A, was launched in 1988 and the latest, IRS-P8, was launched in 2016. IRS satellites are used for a variety of applications, including mapping, land cover classification, and monitoring of natural disasters and environmental changes.
IKONOS:
IKONOS is a commercial Earth observation satellite operated by DigitalGlobe. It was launched in 1999 and is capable of capturing high-resolution images of the Earth’s surface. IKONOS is used for a variety of applications, including mapping, land cover classification, and monitoring of natural disasters and environmental changes.
GEOEYE:
GEOEYE was a commercial Earth observation satellite operator that was acquired by DigitalGlobe in 2013. The company operated a number of Earth observation satellites, including the IKONOS satellite mentioned above.
WORLDVIEW:
WORLDVIEW is a series of commercial Earth observation satellites operated by DigitalGlobe. The first WORLDVIEW satellite, WORLDVIEW-1, was launched in 2007 and the latest, WORLDVIEW-4, was launched in 2016. WORLDVIEW satellites are used for a variety of applications, including mapping, land cover classification, and monitoring of natural disasters and environmental changes.
SENTINEL:
The Sentinel satellite program is a series of Earth observation satellites developed by the European Space Agency (ESA) as part of the Copernicus Earth observation program. The first Sentinel satellite, Sentinel-1A, was launched in 2014 and the latest, Sentinel-5P, was launched in 2017. Sentinel satellites are used for a variety of applications, including mapping, land cover classification, and monitoring of natural disasters and environmental changes.
SkySat
SkySat is a series of remote sensing satellites developed and operated by the company Planet Labs. These satellites are designed to capture high-resolution, high-quality images of the Earth’s surface for a variety of applications, including environmental monitoring, agricultural mapping, urban planning, and disaster response. The SkySat satellites are equipped with advanced imaging sensors and can capture images with a resolution of up to one meter per pixel, making them ideal for detailed mapping and analysis of the Earth’s surface. The SkySat constellation currently consists of over 20 operational satellites, with plans to continue expanding in the future.
Dove
Dove is a remote sensing satellite developed by Planet Labs, a private company based in San Francisco, California. It is a small, lightweight satellite that is designed to capture high-resolution images of the Earth’s surface for a variety of applications, including mapping, monitoring land use and land cover, and disaster response. The Dove satellite has a resolution of 3 meters per pixel and can capture images of an area up to 100 kilometers wide. It is equipped with a visible and infrared camera that allows it to capture both visible and invisible light wavelengths, giving it the ability to detect changes in land cover over time. Dove satellites are launched into low Earth orbit and are able to complete a full orbit of the Earth in just over 90 minutes, allowing them to capture images of nearly every location on the planet.
RapidEye
RapidEye is a remote sensing satellite system that was launched into orbit in August 2009. It consists of five high-resolution imaging satellites that are capable of capturing detailed images of the Earth’s surface. The satellites are equipped with multispectral sensors that allow them to capture images in five different spectral bands, including blue, green, red, red-edge, and near-infrared. This allows the satellites to capture detailed images of the Earth’s surface in a range of different conditions, including during the day and at night.
RapidEye is used for a wide range of applications, including mapping, land use analysis, agricultural monitoring, natural resource management, and disaster response. The high-resolution images captured by the satellites can be used to identify changes in land cover, monitor crop health, and assess the impact of natural disasters. The satellites are also used to monitor the environment, including water bodies, forests, and wetlands, and to track changes over time.
In addition to its remote sensing capabilities, RapidEye also has a suite of advanced data analytics tools that allow users to process and analyze the data collected by the satellites. This includes tools for image processing, data visualization, and geospatial analysis. The combination of high-resolution imaging and advanced data analytics capabilities makes RapidEye a powerful tool for understanding and managing the Earth’s resources.
Marin Observation Satellite: Seasat
launched by NASA in 1978 for the purpose of studying the Earth’s oceans. It was the first satellite specifically designed for ocean observation and was equipped with a suite of sensors including radar, altimeters, and infrared scanners to gather data on sea surface temperature, wave height, and ocean currents. The data collected by Seasat helped improve our understanding of ocean dynamics and how they affect the Earth’s climate and weather patterns. It also provided valuable information for a variety of applications including marine navigation, fishing, and oil exploration. Seasat’s mission ended prematurely due to a failure in its power system, but its legacy lives on through the numerous studies and applications that have used its data.
Nimbus: CZCS, MOS
CZCS (Coastal Zone Color Scanner) was a remote sensing satellite that was launched in 1978. It was designed to measure the concentration of chlorophyll, suspended sediment, and other parameters in the oceans and coasts.
MOS (Multispectral Optical Scanner) is a remote sensing instrument that was used on several satellites, including Nimbus-7 and Landsat 4. It measures the reflectance of the Earth’s surface in multiple wavelengths, providing information about the types of land cover and the presence of certain minerals.
Sea Star: SeaEiFS, Oceansat
Sea Star is a remote sensing satellite developed by SeaEiFS and Oceansat. It is designed to collect data on the oceans and coastal areas, including information on sea surface temperature, currents, and water quality. This data can be used for a variety of purposes, including studying the impacts of climate change, monitoring marine life, and tracking the movement of pollutants. Sea Star is also equipped with imaging capabilities, allowing it to capture high-resolution images of the Earth’s surface. These images can be used for mapping, land use planning, and disaster response efforts. Overall, Sea Star is an important tool for understanding and protecting the world’s oceans and coastal areas.