Remote sensing is a process of getting information about an area without actually being in contact with it. It change the world and it has wide range of applications in different field lets dive in to explore “What Remote Sensing is and how it is used for different purposes
What is Remote Sensing
“Remote sensing (RS) is the science of using instruments or sensors for capturing, detecting and monitoring the physical characteristics and spatial relations of objects and materials in an area by measuring its reflected and emitted radiation at a distance from the targeted area typically above from then using aircrafts, satellite and Drones”
History of Remote Sensing:
Remote sensing began in the 1840s for defense purposes as a balloonist took pictures of the ground using the newly invented photo-camera. It is followed by capturing images of some part of Europe by using pigeons.
After the invention of Sputnik in 1957, the possibility of putting film cameras on orbiting spacecraft was realized. The first astronauts and cosmonauts started work on carrying cameras to sample regions and targets of opportunity as they circumnavigated the globe.
In 1970’s the first satellite Landsat were operate in space for monitoring water and land surface to map natural and cultural resources. It start a new space race, different countries launched their own satellites with different advancement and for different purposes. On the basis of purposes three major groups were defined.
The first group called Primarily Land Observers satellites which includes Landsat series(1-6) (1973); HCMM (1978); Seasat (1978); RESURS (Russia) (1985); SPOT (France) (1-3) (1986); IRS(1A-1D) (India) (1986); BNSCsat) (Algeria, China, Nigeria, Turkey and UK) (2002-2003), and ICESat (USA) (2003) etc.
The second group called Primarily Meteorological Observers includes TIROS (1-9) (1960); Nimbus (1-7) (1964); ESSA (1-9) (1966); ATS(g) (1-3) (1966); DMSP series I (1966); the Russian Kosmos (1968) etc, and the third group base on satellite Use in Oceanography, which includes Seasat (1978); Nimbus 7 (1978) SeaWiFS (1997), JASON 1 (France-USA) (2001), Aqua (EOS PM-1) (USA) (2002) etc.
How Remote Sensing Works
Remote sensing is a process based on different steps which involves an interaction between incident radiation and the target of the interest.
Terrestrial remote sensing term is used for acquiring information about the land and there are seven elements are in the process of imaging system. It also involves the sensing of emitted energy and the use of non-imaging sensors
1. Energy Source or Illumination (A)
The first element is the source of energy. The energy source which provides or illuminates electromagnetic energy to the target of the interest is either generated from sun or sensor own energy.
2. Radiation and the Atmosphere (B)
Atmosphere is composed of different gases and tiny solid particles, as the energy travels from its source to the target, it will come in contact with and interact with the atmosphere it passes through. This interaction may take place a second time when the energy bounce back to the sensor after striking on the target.
3. Interaction with the Target (C)
Once the energy reach to the target by making way through the atmosphere, it interacts with the target depending on the properties of both the target spectral signature and the radiation.
4. Recording of Energy by the Sensor (D)
An instrument requires receiving the spectral signature of target; this instrument is known as sensor. Sensor collects and records the electromagnetic radiation.
5. Transmission, Reception, and Processing (E)
Sensor transmits the recorded signature analog form to a receiving and processing station where the analog data are processed and converted into an image.
6. Interpretation and Analysis (F)
After creating images the next step is to extract information by interpreting and analyzing it visually and/or digitally or electronically.
7. Application (G)
Application is the final element of remote sensing process. It is the usage of information extracted from the imagery to solve a problem, create a spatial plan, monitor crops and much more
All these are the basic elements of remote sensing process form beginning to end.
Uses of Remote Sensing
There are huge list uses of remote sensing but I wrote some specific uses of remotely sensed data of the Earth include:
- Land cover can be mapped from space, allow user to analyze any part of the world without visiting that location.
- Mapping disaster destruction’s in any area using real time imageries
- Monitoring large agricultural fields using drone remote sensing
- Catching forest fires effected areas and forecast how much area will affect in particular time.
- Remote sensing allows share any information regarding movement in wars and operations.
- It facilitates to Track clouds to help predict the weather or you can watch erupting volcanoes, and help watch for dust storms.
- Remote sensing techniques help to map the ocean floor its rugged topography such as Deep canyons, magnetic strips, and huge mountain ranges.
In short remote sensing is the technique of acquiring information remotely about the target using radiations. These radiations are bounce back from the target and receive by sensor, then transmit to the receiving station where it converted into image format. It can interpret using different themes to solve a particular problem. It used in different sector including agriculture, defense, mapping, planning Aviation etc.