The word remote implies something that we can see but do not usually have physical contact with. On the other hand, sensing means collecting data on an object and interpreting the data. Therefore, remote sensing can be referred to as the process in which we collect and interpret data from an object which is not in physical contact with us.
Well, when the object or the phenomenon regarding which we need to collect data is not present in front of us, then one can only collect the data with the help of satellites. Even aeroplanes or any other aerial technology could be used to collect and interpret the data.
Remote sensing: Elements
- A target is usually an object or a phenomenon, or a place
- A platform is required, which would simply help to keep or hold the instrument.
- A sensor or an instrument is also required, with the help of which the object that is targeted could be observed.
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Remote sensing: What are the two types of remote sensing?
- Active remote sensing– In this mode of remote sensing, aerial sensors are used. Here the object or the phenomenon is first located regarding which one needs to collect data. Then the sensor is used to produce radiation and transmit it to that place or object.
When the object or the phenomenon reflects the radiation, the data is collected from it. Some examples of active sensors are Radar and Lidar. They help in finding out the delay in time between emission and return.
- Passive remote sensing– In this mode of remote sensing, the source of radiation is natural, like the sun, and aerial sensors are not used in this case. Here the object reflects the radiation that it receives from the sun naturally.
Satellites, aeroplanes, and various other orbital platforms are used to transmit the data received in the terrestrial stations. The data and the images collected are then analysed thoroughly to get information.
Passive sensors are more popular than active sensors as they produce good-quality satellite images, which makes it easier to analyse and archive the data.
Remote sensing: Technical fields where we have applications of remote sensing
Keeping track of weather conditions with the help of laser and radar altimeters, good-quality images can be produced, with tons of data that could be collected to determine the weather conditions. Various other fields like surface changes, agriculture, biodiversity, and forestry also use remote sensing technologies.
Remote sensing: Technologies that play a vital role in remote sensing
A conventional radar can help in finding out clear images of an object or a phenomenon, but for more complicated tasks, various technological implementations are needed.
- Light detection and ranging technology could be easily used if you need to have a three-dimensional study of an object or an area like a forest area.
- Sensing density is complicated, but it can be assessed with the help of stereographic image comparison.
- To obtain high-resolution data, multi-spectral and hyperspectral imaging could be easily used.
Remote sensing: Advantages
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Remote sensing helps in providing the latest information as well as helps in planning and management. Most applications of remote sensing are used for sustainable development, disaster management, environmental degradation, and natural resource management. It is also used in the development processes like soil, forestry, geology, and agriculture.
Remote sensing is one of the most advanced technologies that can be used to find out information about an object which is at a great distance from the observer. Mostly information on those objects is studied that is not at all accessible by the observer. It helps in accurate and detailed studying of the dimensions and readings of a particular area.
Active and passive sensors can operate in the microwave regions and the ultraviolet regions of the electromagnetic spectrum. This is the main reason why it can collect a wide range of data easily. Also, the satellites are recording all the information constantly. There are various satellite systems, and they could differentiate on the following basis:
- Spatial Resolution
- Radiometric Resolution
- Radiometric Resolution
- Temporal Resolution
Data for various features of a particular location could be easily obtained with remote sensing. In fact, this data and the images can be regularly updated for all areas throughout the globe by the orbital sensors. The entire process is automatic, and no sort of human intervention is required for this. The data alongside the imagery collected with the satellites’ help are used for further research and are also available to us as maps.
Application of remote sensing: Top 6 applications
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Agriculture
When farming is to be done in precision, satellite data is extensively used. Remote sensing is one of the best possible methods with the help of which agricultural viability could be studied. To have a detailed understanding of crop type classification and assess the growth and estimate the yield of crops. It can also be used to determine the condition of the crops.
Farmers can also easily identify to which extent crops are damaged if a calamity occurs or there are storms. The data on the crops could be collected, and then further steps can be decided.
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Monitoring drought and weather patterns
The weather patterns, as well as the drought patterns of a particular area that is to be studied, could be easily determined with the help of the images that are obtained from the satellites. The amount of rainfall that has occurred in the place and the duration of the rainfall that has occurred can also be determined.
The extensive data collected with remote sensing also allows for calculating and estimating the time duration of the next rainfall. By obtaining all this information, you can control and keep track of the drought conditions.
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Forest mapping
Usually, for forest mapping, traditional ground surveys were used. But they were only a suitable option sometimes. Instead, remote sensing technology could be used quite easily to obtain images of large tracts of forests. It allows us to obtain the most minute details, such as the density and textures of a leaf, accurately.
The forests could be easily mapped, identified, and delineated with the help of remote sensing techniques. The picture of areas where deforestation has been done could be easily studied with the help of the pictures that are obtained. With this information, we could establish settlement areas in those places where deforestation has taken place.
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Assessing the weather
Interesting patterns and pictures of the atmosphere could be easily obtained with the help of remote sensing techniques. This data is quite valuable and accurate for the meteorological and climatological study that is done throughout the world. It can also be used to make predictions related to natural calamities that might occur anytime soon.
The rise of global warming in recent decades is a matter of concern, and all information regarding the same could be easily obtained with the help of remote sensing. The change in climatic conditions over the years can be easily studied to plan for the future. With the help of this, future drought conditions or extreme natural calamities could be predicted.
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Land use and land cover analysis
Most of the time, these terms are used quite simultaneously, but they have different meanings altogether. They play a significant role in planning, managing, and monitoring programs at local, regional, and national levels.
The amount of a region that is covered by forests, wetlands, impermeable surfaces, farmland, and other land and water types is recorded by land cover data. On the other hand, land use data shows how people use the landscape-whether for development, conservation, or mixed uses. It involves modifying the natural environment into a built environment such as a settlement and semi-natural environment.
With the help of remote sensing, the properties or information about land cover could be easily estimated. Based on this information, land use could be decided. The satellite images give a clear view of the land cover, and they help you to know which land is suitable for what purpose. Whether the land could be used for agricultural purposes or for building settlements can be easily determined.
There are many wide areas where remote sensing has an application, such as baseline mapping for a geographic information system. It is also used for the delineation of flooding, earthquakes, tornadoes, fire, wildlife habitat protection, target detection, and boundaries for property evaluation
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Civil engineering study
Urban planning and development are one of the most popular areas where remote sensing technologies are used. Civil engineering is one of those fields where remote sensing has extensive applications. Water resources that are nearby, factories, and hydrological models are some of the factors that influence the settlement development study. Information regarding all these factors could be obtained with the help of remote sensing technology. It also helps maintain the environmental balance if the data pertaining to these are obtained accurately as well as on time.
FAQs
What is a satellite?
The objects that constantly revolve around the planes are referred to as satellites. We have both natural and artificial satellites. For example, the moon is the earth's satellite.
What is satellite imagery?
The images are obtained through satellites that are in a continuous motion around the planets. We could find images of the entire globe with their help.
What do you mean by an optical sensor?
Optical sensors are the ones that are responsible for detecting solar radiation. This solar radiation is either reflected from the earth’s surface or scattered from the surface of the earth.
