{"id":5635,"date":"2026-01-04T22:42:40","date_gmt":"2026-01-04T17:12:40","guid":{"rendered":"https:\/\/vajiramandravi.com\/upsc-exam\/?p=5635"},"modified":"2026-01-05T11:49:33","modified_gmt":"2026-01-05T06:19:33","slug":"remote-sensing","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/upsc-exam\/remote-sensing\/","title":{"rendered":"Remote Sensing, Types, Process, Applications, UPSC Notes"},"content":{"rendered":"

Remote sensing is the total process used to acquire and measure the information of some properties of objects and phenomena<\/strong> by a recording device (sensor<\/strong>) that is not in physical contact with the objects or the phenomena under study. Remote sensors<\/strong>, which provide a global perspective <\/strong>and a plethora of data about Earth systems<\/strong>, allow for data-driven decision-making based on our planet's existing and future state.<\/p>\r\n

In India, space remote sensing has proven to be a valuable tool for monitoring crops, forests, water resources, minerals, wastelands, ocean and marine resources, and assisting with drought andflood control.<\/p>\r\n

Remote Sensing Meaning<\/h2>\r\n

Remote sensing is the use of electromagnetic energy<\/strong> to determine the physical characteristics of distant objects. It comprises <\/strong>photography, geophysical surveying, and newer techniques that use other areas of the electromagnetic spectrum.<\/strong><\/p>\r\n

    \r\n\t
  • The history of remote sensing begins with photography. Other types of remote sensing date back to World War II<\/strong>, when radar<\/strong>, sonar<\/strong>, and thermal infrared detecting devices were developed.<\/li>\r\n\t
  • Since the 1960s, sensors <\/strong>have been developed to function in practically the whole electromagnetic spectrum.<\/li>\r\n<\/ul>\r\n

    Types of Remote Sensors<\/h2>\r\n

    Remote sensors gather data by detecting the energy <\/strong>reflected from the Earth. These sensors can be installed on satellites or in aircraft. Remote sensors may be either passive or active.<\/p>\r\n

      \r\n\t
    • Passive Sensors: <\/strong>Passive sensors respond to external stimuli.<\/strong> They measure natural energy that is reflected or emitted from the Earth's surface. <\/strong>The most prevalent type of radiation measured by passive sensors is reflected sunlight<\/strong>.<\/li>\r\n\t
    • Active Sensors:<\/strong> Active sensors collect data about the Earth by detecting internal stimuli. For instance, a laser-beam remote sensing system<\/strong> shines a laser onto the Earth's surface and measures the time it takes for the laser to reflect to its sensor.<\/li>\r\n<\/ul>\r\n

      Remote Sensing Process<\/h2>\r\n

      Remote Sensing is a process in which incoming radiation <\/strong>interacts with the target of interest. This is done by using imaging <\/strong>and non-imaging systems<\/strong>; the following steps are involved in the process:<\/p>\r\n

        \r\n\t
      • Energy Source or Illumination (A):<\/strong> The initial prerequisite for remote sensing is an energy source that illuminates or delivers electromagnetic radiation<\/strong> to the target of interest. The Sun <\/strong>is the primary source of energy used in remote sensing.<\/li>\r\n\t
      • Radiation and the Atmosphere (B): <\/strong>As energy moves from its source to its target, it comes into contact with and interacts with the atmosphere <\/strong>it passes through.<\/li>\r\n\t
      • Interaction with the Target (C):<\/strong> Once the energy passes through the atmosphere and reaches the target, it interacts with it based on the qualities of both the target and the radiation.<\/li>\r\n\t
      • Recording of Energy by the Sensor (D):<\/strong> After the energy is scattered or emitted from the target, the sensor gathers and records the electromagnetic radiation.<\/li>\r\n\t
      • Transmission, Reception, and Processing (E)<\/strong>: The energy recorded by the sensor must be sent, frequently electronically, to a receiving and processing unit where it is converted into a picture (hardcopy and\/or digital).<\/li>\r\n\t
      • Interpretation and Analysis (F):<\/strong> The processed image is interpreted, visually and\/or digitally, to extract information about the target that was illuminated.<\/li>\r\n\t
      • Application (G): <\/strong>The remote sensing process concludes when the extracted imagery information is applied to understand the target, reveal new information, or solve specific problems.<\/li>\r\n<\/ul>\r\n

        India and Remote Sensing<\/h2>\r\n

        Over the past two decades, India has achieved significant progress in space technology and applications for monitoring and management and natural resources. The successful launch and operationalization of IRS-1B<\/strong> and the continued satisfactory functioning of IRS-IA <\/strong>beyond its design life of three years are millstones in the Indian Remote Sensing programme.<\/strong><\/p>\r\n

          \r\n\t
        • The Indian Remote Sensing Satellite (IIRS) programme <\/strong>was launched in 1988 and is a major step forward in the overall programme for using space technology<\/strong> for defined applications in India.<\/li>\r\n<\/ul>\r\n

          Indian Institute of Remote Sensing<\/h3>\r\n

          The IIRS is a part of the Indian Space Research Organisation (ISRO)<\/strong>.<\/p>\r\n

            \r\n\t
          • Since its establishment in 1966, IIRS has been a key player in training and capacity building in geospatial technology<\/strong> and its applications through training, education, and research in Southeast Asia.<\/li>\r\n\t
          • Other Institutions related to Remote Sensing are:<\/strong>\r\n
              \r\n\t
            • National Remote Sensing Centre (NRSC): <\/strong>It is responsible for remote sensing satellite data acquisition and processing, data dissemination, aerial remote sensing, and decision support for disaster management.\r\n\r\n
                \r\n\t
              • NRSC is the nodal centre<\/strong> for hosting Satellite Data Products from more than 13 IRS satellites<\/strong>, dating back to the first IRS optical mission, IRS-1A<\/strong>, and the SAR imaging mission<\/strong>.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
              • Regional Remote Sensing Centres (RRSCs):<\/strong> They support various remote sensing tasks specific to their regions as well as at the national level.<\/li>\r\n<\/ul>\r\n

                Indian Remote Sensing Satellite<\/h3>\r\n

                The Indian Remote Sensing (IRS<\/strong>) satellites are the mainstay of the National Natural Resources Management System (NNRMS)<\/strong>, for which the Department of Space (DoS) is the nodal agency, providing operational remote sensing data services.<\/p>\r\n

                  \r\n\t
                • Starting with IRS-1A in 1988, ISRO has launched many operational remote sensing satellites. Some of the recently launched remote sensing satellites are mentioned below in the table:<\/li>\r\n<\/ul>\r\n
                  \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
                  Name<\/strong><\/td>\r\nLaunch Year<\/strong><\/td>\r\nApplication<\/strong><\/td>\r\n<\/tr>\r\n
                  EOS-07<\/strong><\/td>\r\n2023<\/td>\r\nEarth Observation<\/td>\r\n<\/tr>\r\n
                  EOS-06<\/strong><\/td>\r\n2022<\/td>\r\nEarth Observation<\/td>\r\n<\/tr>\r\n
                  EOS-04<\/strong><\/td>\r\n2022<\/td>\r\nEarth Observation<\/td>\r\n<\/tr>\r\n
                  EOS-02<\/strong><\/td>\r\n2021<\/td>\r\nEarth Observation<\/td>\r\n<\/tr>\r\n
                  EOS-01<\/strong><\/td>\r\n2020<\/td>\r\nDisaster Management System, Earth Observation<\/td>\r\n<\/tr>\r\n
                  RISAT-2BR1<\/strong><\/td>\r\n2019<\/td>\r\nDisaster Management System, Earth Observation<\/td>\r\n<\/tr>\r\n
                  Cartosat-3<\/strong><\/td>\r\n2019<\/td>\r\nEarth Observation<\/td>\r\n<\/tr>\r\n
                  HysIS<\/strong><\/td>\r\n2018<\/td>\r\nEarth Observation<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n

                  Applications of Remote Sensing<\/h2>\r\n

                  The applications include groundwater exploration, physical water quality determination, snowfield mapping, flood-inundation delineation, and irrigated land inventories.<\/p>\r\n

                    \r\n\t
                  • Agriculture:<\/strong> Remote sensing is utilised for crop identification<\/strong>, production forecasting, damage and progress assessment, soil mappin<\/strong>g and moisture estimation, and mapping of agricultural water resources.<\/strong><\/li>\r\n\t
                  • Coastal:<\/strong> Monitor shoreline <\/strong>changes, track sediment transport, and map coastal features. Data can be used for coastal mapping and erosion <\/strong>prevention.<\/li>\r\n\t
                  • Ocean:<\/strong> Monitor ocean circulation and current systems, measure ocean temperature<\/strong> and wave heights, and track sea ice.<\/li>\r\n\t
                  • Hazard assessment: <\/strong>Track hurricanes, earthquakes, erosion, and flooding. Data can be used to assess the effects of natural disasters<\/strong> and develop preparedness plans for both before and after a hazardous event.<\/li>\r\n\t
                  • Natural resource management:<\/strong> Track land use, map wetlands, and identify wildlife habitats<\/strong>. Data can be used to reduce the environmental impact of urban development <\/strong>and to determine the best way to protect natural resources.<\/li>\r\n\t
                  • Weather Forecasting:<\/strong> It is extensively used to study weather patterns, precipitation, and temperature changes.\r\n\r\n
                      \r\n\t
                    • Satellite remote sensing provides a way to measure land surface temperature (LST) and generate various LST products at regional and global scales.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                    • Environment:<\/strong> Atmospheric models employ remote sensing data to determine the sources and sinks of greenhouse gases<\/strong>at specific locations.\r\n\r\n
                        \r\n\t
                      • Satellite and aircraft-borne remote sensors <\/strong>can cover a larger area than in-situ sensors and have the potential to reveal GHG emission sources and hotspots, such as methane leaks.<\/strong><\/li>\r\n\t
                      • Remote sensing offers the possibility to estimate and map canopy chlorophyll content accurately.\r\n\r\n
                          \r\n\t
                        • As accurate and accurate estimates of canopy chlorophyll content are critical for effective ecosystem monitoring.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                          Remote Sensing UPSC PYQs<\/h2>\r\n

                          Question 1:<\/strong> For the measurement\/estimation of which of the following are satellite images\/remote sensing data used? (UPSC Prelims 2019)<\/strong><\/p>\r\n

                            \r\n\t
                          1. Chlorophyll content in the vegetation of a specific location<\/li>\r\n\t
                          2. Greenhouse gas emissions from rice paddies of a specific location<\/li>\r\n\t
                          3. Land surface temperatures of a specific location<\/li>\r\n<\/ol>\r\n

                            Select the correct answer using the code given below.<\/p>\r\n

                              \r\n\t
                            1. 1 only<\/li>\r\n\t
                            2. 2 and 3 only<\/li>\r\n\t
                            3. 3 only<\/li>\r\n\t
                            4. 1, 2 and 3<\/li>\r\n<\/ol>\r\n

                              Answer: (d)<\/strong><\/p>\r\n

                              Question 2: <\/strong>In which of the following activities are Indian Remote Sensing (IRS) satellites used? (UPSC Prelims 2015)<\/strong><\/p>\r\n

                                \r\n\t
                              1. Assessment of crop productivity<\/li>\r\n\t
                              2. Locating groundwater resources<\/li>\r\n\t
                              3. Mineral exploration<\/li>\r\n\t
                              4. Telecommunications<\/li>\r\n\t
                              5. Traffic studies<\/li>\r\n<\/ol>\r\n

                                Select the correct answer using the codes given below.<\/p>\r\n

                                  \r\n\t
                                1. 1, 2 and 3 only<\/li>\r\n\t
                                2. 4 and 5 only<\/li>\r\n\t
                                3. 1 and 2 only<\/li>\r\n\t
                                4. 1, 2, 3, 4 and 5<\/li>\r\n<\/ol>\r\n

                                  Answer: (a)\u00a0<\/strong><\/p>","protected":false},"excerpt":{"rendered":"

                                  Remote Sensing is the science of obtaining information about objects or areas from a distance, typically from satellites. Check about Remote Sensing, Types, Process, Applications, UPSC Notes<\/p>\n","protected":false},"author":6,"featured_media":5636,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[239],"tags":[40,864],"class_list":{"0":"post-5635","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-quest-level-4","8":"tag-quest","9":"tag-remote-sensing"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/5635","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/comments?post=5635"}],"version-history":[{"count":1,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/5635\/revisions"}],"predecessor-version":[{"id":19826,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/5635\/revisions\/19826"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media\/5636"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media?parent=5635"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/categories?post=5635"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/tags?post=5635"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}