Satellites and Services - Satellite Applications
3. Remote Sensing
Remote sensing is the process of acquiring information about the Earth's surface, atmosphere, and oceans from a distance, typically using satellites, aircraft, or other platforms. Earth observation satellites are specifically designed and equipped to capture high-resolution images and other data about the Earth's surface, atmosphere, and oceans.
The data gathered by Earth observation satellites can be used in a wide range of applications, including:
Weather forecasting: Satellites can be used to track weather patterns, monitor atmospheric conditions, and provide data for weather models and forecasts.
Natural resource management: Satellites can be used to monitor land use, crop growth, and other environmental factors to help manage natural resources and prevent environmental degradation.
Disaster monitoring: Satellites can be used to monitor natural disasters such as hurricanes, floods, and wildfires, and provide early warning and response information to emergency responders.
Urban planning and infrastructure management: Satellites can be used to monitor and map urban areas, track urban growth, and identify areas that require infrastructure development or improvements.
Archaeology and cultural heritage: Satellites can be used to map and analyze archaeological sites and cultural heritage areas, helping to preserve and protect these important resources.
Overall, remote sensing with Earth observation satellites is a powerful tool for understanding and managing the Earth's natural and built environments, and for addressing a wide range of scientific, social, and economic challenges.
a) Satellites systems that support remote sensing services
Several satellite systems support remote sensing, including:
1. Landsat: Landsat is a series of Earth observation satellites operated by the US Geological Survey (USGS) and NASA. These satellites capture images in several bands of the electromagnetic spectrum, including visible, near-infrared, and thermal infrared, to monitor land use, vegetation cover, and other factors.
2. Sentinel: The Sentinel series of Earth observation satellites is operated by the European Space Agency (ESA) and the European Commission. These satellites capture images in several bands of the electromagnetic spectrum, including visible, near-infrared, and microwave, to monitor a wide range of environmental factors, such as land use, vegetation cover, and sea ice extent.
3. MODIS: The Moderate Resolution Imaging Spectroradiometer (MODIS) is a key instrument on several Earth observation satellites, including NASA's Terra and Aqua satellites. MODIS captures images in several bands of the electromagnetic spectrum, including visible, near-infrared, and thermal infrared, to monitor a wide range of environmental factors, such as land use, vegetation cover, and atmospheric conditions.
4. GOES: The Geostationary Operational Environmental Satellite (GOES) series is operated by the US National Oceanic and Atmospheric Administration (NOAA). These satellites capture images in several bands of the electromagnetic spectrum, including visible and infrared, to monitor weather patterns and atmospheric conditions in real-time.
The specific frequency bands used by these satellite systems depend on the type of sensor being used and the type of data being collected. Landsat and Sentinel, for example, use a range of optical and infrared sensors that operate in the visible, near-infrared, and thermal infrared portions of the electromagnetic spectrum. GOES and other weather monitoring satellites use sensors that operate in the visible and infrared portions of the spectrum. Some remote sensing applications, such as microwave remote sensing, use sensors that operate in the microwave portion of the spectrum.
b) Ground infrastructure is required for satellite remote sensing operations
Satellite remote sensing operations require a specialized ground infrastructure to receive, process, and distribute the data collected by the satellites. The ground infrastructure typically consists of:
1. Ground stations: These are specialized facilities that receive the satellite data and transmit it to the processing centers. The ground stations are typically located in remote areas where there is minimal interference from other radio signals.
2. Data processing centers: These centers are responsible for processing the raw data received from the ground stations into usable information. The data is processed using specialized software and algorithms to create images and other data products.
3. Data distribution networks: Once the data has been processed, it needs to be distributed to the end-users. This is done through specialized data distribution networks that allow users to access the data over the internet or other communication channels.
4. Data archives: The processed data is typically stored in long-term data archives for future use. These archives are typically managed by specialized organizations, such as government agencies or research institutions.
5. Support facilities: In addition to the above, satellite remote sensing operations require a range of support facilities, including power and cooling systems, backup generators, security systems, and maintenance facilities.
c) Publicly accessible remote sensing information
Some remote sensing information collected by satellites is publicly available. For example, the USGS (United States Geological Survey) provides access to Landsat satellite imagery through its EarthExplorer website, which allows users to search, preview, and download a wide range of satellite data products. Additionally, the European Space Agency's (ESA) Sentinel satellites offer a range of free and open data products, including imagery and data on land, ocean, and atmospheric conditions.
To access and process this information, users typically need to have some familiarity with remote sensing and image processing software. There are many commercial and open-source software tools available for processing remote sensing data, including ENVI, ArcGIS, QGIS, and Google Earth Engine. Many of these tools offer a range of analysis capabilities, such as image classification, change detection, and feature extraction, which can be used to extract information from satellite data. Some of these tools are free or open-source, while others require a license or subscription.
Accessing USGS Landsat imagery
The USGS (United States Geological Survey) provides free public access to Landsat imagery through its EarthExplorer platform. Here are the steps to access the imagery:
1. Go to the EarthExplorer website: https://earthexplorer.usgs.gov/
2. Create an account if you don't have one already. It's free to create an account.
3. Once you're logged in, you can search for Landsat imagery by specifying the location and time period of interest. You can also select the type of data you're interested in (e.g., Landsat 5, Landsat 7, or Landsat 8).
4. Once you've selected your search parameters, click "Results" to see a list of available images.
5. You can preview the images by clicking on the thumbnail. To download the image, select the checkbox next to it and click "Download." You'll be prompted to select a format and specify the download location.
The downloaded image can be processed using various software packages, such as QGIS, ArcGIS, or ENVI, among others.
Accessing European Space Agency's (ESA) Sentinel satellites imagery
The European Space Agency's (ESA) Sentinel satellite data can be accessed through the Copernicus Open Access Hub, which is the official portal for the Copernicus program, a European Union program for monitoring the Earth. The Copernicus Open Access Hub provides free access to all Sentinel satellite data, as well as other data from the Copernicus program.
To access the data, users need to create an account on the Copernicus Open Access Hub website and then search for the data they need using the search tools. The data can be previewed before downloading and users can choose the format and data products they need. Once the data is downloaded, it can be processed and analyzed using various software tools, including the Sentinel Application Platform (SNAP) software, which is available for free download from the ESA website. SNAP provides a wide range of tools for processing and analyzing Sentinel data, including tools for image processing, data visualization, and data analysis.
India's remote sensing information that is available to public
The Indian Space Research Organisation (ISRO) offers remote sensing data to the public through the National Remote Sensing Centre (NRSC). The data is available in various forms, including raw data, processed data, and value-added products.
To access the data, interested users can visit the NRSC website (https://bhuvan.nrsc.gov.in/data) and select the desired data set. The data can be downloaded directly or requested through email. Users will need to create an account and agree to the terms and conditions before accessing the data.
ISRO also provides a web-based geoportal called "Bhuvan" (https://bhuvan.nrsc.gov.in/), which provides satellite imagery and related services. The Bhuvan portal provides multi-resolution, multi-temporal, and multi-platform satellite data, which can be used for various applications, including disaster management, agriculture, forestry, water resources, and environmental monitoring. The data can be accessed by registered users through a web browser or a mobile application.
Processing software is compatible with Bhuvan imagery:
Bhuvan is a web-based geoportal developed by the Indian Space Research Organisation (ISRO) that provides satellite imagery and geospatial data of India. Bhuvan provides a range of tools to access and visualize different types of geospatial data. Bhuvan imagery can be processed using a range of software tools, including open-source software such as QGIS, Grass GIS, and the Remote Sensing Application Platform (RSAP). Additionally, ISRO has developed its own image processing software called Bhuvan Panchayat, which is specifically designed for processing Bhuvan imagery for applications in rural development and planning. The software is available for download from the Bhuvan website.
d) Softwares are available for processing remote sensing imagery
There are several software packages available for processing remote sensing data received from satellites. Some of the popular software packages used for processing remote sensing data include:
1. ENVI: ENVI is a software package developed by Harris Geospatial that is widely used for processing and analyzing remote sensing data. The software includes a range of tools for image processing, data analysis, and data visualization.
2. ERDAS Imagine: ERDAS Imagine is a software package developed by Hexagon Geospatial that is widely used for processing and analyzing remote sensing data. The software includes a range of tools for image processing, data analysis, and data visualization.
3. ArcGIS: ArcGIS is a software package developed by Esri that is widely used for processing and analyzing remote sensing data. The software includes a range of tools for spatial analysis, mapping, and data visualization.
4. QGIS: QGIS is a free and open-source software package that is widely used for processing and analyzing remote sensing data. The software includes a range of tools for image processing, data analysis, and data visualization.
5. MATLAB: MATLAB is a software package developed by MathWorks that is widely used for processing and analyzing remote sensing data. The software includes a range of tools for image processing, data analysis, and data visualization.
6. PCI Geomatica: PCI Geomatica is a software package developed by PCI Geomatics that is widely used for processing and analyzing remote sensing data. The software includes a range of tools for image processing, data analysis, and data visualization.
These software packages are widely used in the remote sensing community and are designed to handle a wide range of remote sensing data types and formats.
