Applications Of Remote Sensing Environmental Sciences Essay

actions Of far Sensing Environmental Sciences EssayRemote detecting technique has emerged as an stiff creature for systematic survey, synopsis, and better precaution of native re generators ( place down, turd, pee, forests, mountains) along with the monitoring of desertification, flood, drought, and landform change. It offers a vast scope to explore, identify, and snap the natural imaginations of undeveloped regions. It documents the dynamic changes in corporeal processes and resulting landforms, usually by satellite images. This paper provides a general overview of contrary control spying. While this technique has been utilise on beaches, valleys, and other landforms, the main concern of this paper is its authority in geography.Key Words Remote Sensing, geography, ApplicationIntroduction despite advances in geographical studies, the methods of traditional geography suffer become substandard to apprehend its reality and complexity, considering expert and scie ntific changes that have happened in the locomote 30 years. However, this does not mean that these changes argon not useful for geographic research. This has become evident now that Geographical In governing body Systems (GIS) be ontogeny spacial studies to appeal to such technologies as upstage percept and figurer sciences (MEC, 1999).This paper focuses on a particular research tool for geographic research completen as outside(a) catching. This benefits the psychoanalyze of geography in numerous ways, especially as a research tool, a tool for collecting high quality selective information, and a tool that aids in the reasoning process. It achieves these tasks by virtue of its spacial and temporal coverage (Rhoads, 2004 Doreen, 2009). Geographers more and more use outback(a) controlly sensed data to obtain data virtually the res publicas land grow, ocean, and line because it supplies objective information at a mutation of spatial scales (local to global), provide s a synoptic view of the argona of interest, entrusts access to removed(p)/inaccessible sites, provides spectral information outside the visible portion of the electromagnetic spectrum, and facilitates studies of how features change over time. This data may be analyzed some(prenominal)ly or in conjunction with other digital data layers (e.g. in a GIS).General Overview of Remote SensingAlthough this paper is mainly implicated with remote sleuthing used for geography, the knit stitch of remote sensing is very wide in data acquisition methods, data processing procedures, and respective(a) techniques and applications programmes. at that placefore, it is useful to provide a general overview about several primary(prenominal) topics regarding remote sensing of the surface of the earth. The text in addition attempts to give the contributor an judgement of the capabilities and limitations of remote sensing. Very few equations and formulas will be assumption in the text, as the focus will be on understanding the basic ideas.Remote sensing is defined according to certain functions. It involves acquiring the information of an objects property by a dev methamphetamine not in contact with that object under study. This involves the utilization at a standoffishness of any device for gathering information pertinent to the environs, such as measurements of force fields, electromagnetic radiation, or acoustic energy for aircraft, spacecrafts, or ships. The technique employs such devices as a cameras, lasers, radio frequency receivers, radio detection and ranging systems, sonars, seismographs, gravimeters, magnetometers, and glistering counters. Some examples of remote sensing applications be given in the orbital cavitys that have immenseness for the geographers. Due to the wide scope cover, the subjects could not be covered in detail and the interested reader should turn to the relevant literary productions (Lille common sense Kiefer, 2000 Sabins, 2007 Jen son, 2007 Longley et. al., 2005 Shukla Pathak 2009).As humans, we are intimately familiar with remote sensing in that we rely on visual perception to provide us with a great deal of the information about our surroundings. As sensors, however, our eyes are greatly special by sensitivity to only the visible range of electromagnetic energy, demo perspectives dictated by the fix of our bodies, and the in mogul to form a unchangeable record of what we view. Because of these limitations, humans have continuously sought to develop the technological means to increase our ability to record the physical properties of our environment.Beginning with the primal use of aerial photography, remote sensing has been recognized as a valuable tool for viewing, analyzing, characterizing, and making decisions about our environment. In the past few decades, remote sensing technology has advanced on three fronts from pre ascendently military uses to a variety of environmental analysis applications that relate to land, ocean, and atmosphere issues from analogue photographic systems to sensors that convert energy from many parts of the electromagnetic spectrum to electronic signals and from aircraft to satellite platforms.1.1 Modern Advantages of Remote SensingRemote sensing technology is becoming more serious in geography due to attention organism paid to the latest information, planning, and management for public and hidden interests. It is most useful for natural resource management, sustainable development, environmental degradation, and tragedy management. Its satellite data are used as basic inputs for the fund of natural resources and development processes like agriculture, soil, forestry, and geology (Chavez et al., 1977). There are other classical technologies that are available to geographers as well, such as symbolises, aerial photography/photogrammetry/pictometry, SAR, LiDAR, echo sounder, and GIS. The next section discusses the technologies mentioned above along with the similarities and differences between them and the field of remote sensing.1.1.1 Maps According to the International cartographical Union, a map is a alter image representing selected features or characteristics of geographical reality, intentional for use when spatial relationships are of primary importance. This definition declares that in every map there is scientific accuracy and a process of selection present (symbolization, abstraction, generalization). However, the International Cartographic Union adds that a map shows us the world as we know it, and what we know is a very complex subject that is comprised of The limits of matter, technology, and our measurement tools what we deliberate that exists what we think to be serious and what we want and aspire to. Thus, a map is subjective, for we always decide what to put on it and how to represent it. A remote sensing image, in contrast, is an objective recording of the electromagnetic reaching the sensor. other important difference is that a map is a projection of the earth on paper without any relief displacements, piece of music in a remote sensing image it is a projection of relief displacements and geometric distortions.1.1.2 Aerial Photography/Photogrammetry/Pictometry These systems gather data about the upper surface of the earth by measuring the electromagnetic radiation from airborne systems. The major(ip) differences are detailed belowAerial photos are taken by an analogue instrument (the film of a photogrammetric camera), then s elicitned to be modify to digital media. The advantage of a film is its high resolution (granularity), while the advantage of the CCD is that we measure quantitatively the radiation reaching the sensor (radiance values, quite of a gray-value scale bar). Thus, remote sensing data apprise be integrated into physical equations of energy-balance.An aerial photograph is a central projection, with the alone picture taken at one instance. A remote sensin g image is created line after line, so the geometrical correction is often more complex, with each pixel take uping to be treated as a central projection.Aerial photographs usually gather data only in the visible spectrum, while remote sensing sensors can be designed to measure radiation along the electromagnetic spectrum.Pictometryis the name of a procureaerial imagecapture process of the Pictometry International Corp., USA. It pull ins tomography showing the fronts and sides of objects and locations on the grunge. Images are captured by low-flying airplanes, depicting up to 12 obliqueperspectives as well as anorthogonalview of every location flown. These perspectives can then be stitched together to create complex aerial maps that seamlessly cover large areas. Pictometry resource can be overlaid with heterogeneous shape files because every pixel isgeoreferencedto its exact location on the earth.This allows pictometry imagery to be integrated into many existingGISsoftware applicationsfor use in many areas.Direct measurements can be made on pictometry imagery that complicates area, distance, height, bloom, pitch, and bearing (http//www.pictometry.com).1.1.3 SAR Synthetic Aperture Radar (SAR) provides imagery during night or in bad weather as well as during the day. SAR images can be utilized for earth resource function and environmental monitoring, which require freehanded-area resourcefulness at high resolutions. Synthetic aperture radio detection and ranging complements photographic and other optical imaging capabilities because of the minimum constraints on the time-of-day, atmospheric conditions, and unique responses of terrain/cultural objects to radar frequencies.Synthetic aperture radar technology can provide terrain structural information to geologists for mineral exploration, oil spill boundaries on water to environmentalists, ice fate maps to navigators, and reconnaissance-targeting information to military operations.1.1.4 LiDAR Li ght Detection and Ranging (LiDAR) is another technique that offers several advantages over the conventional methods of topographic data collection. This technique provides data with higher(prenominal) density, higher accuracy, less time for data processing, light independence, and minimum ground control points required. Due to these characteristics, LiDAR is complementing conventional techniques in some applications while wholly replacing them in several others.Various applications where LiDAR data are being used are geomorphology, glacier studies, forest biomass mapping, and generation of the digital elevation model.1.1.5 sonar The echo sounder can also be considered as remote sensing by studying the surfaces of the sea (bathymetry and sea bed features) from a distance. The SONAR is an active geek of remote sensing but with sound ranges or else of electromagnetic radiation (like Radar, it does not depend on an external source of waves). Both systems transmit waves through an i nterfering medium (water, air) that adds randomness to the data. For corrections, these mustiness be utilize to the raw data collected. In remote sensing, however, radar is considered to be almost weather-independent, and atmospheric disturbances affect mainly passive remote sensing. To make these necessary corrections, both systems depend on calibration from field data (be it salinity, temperature, pressure measured by the ship while surveying, or measurements of the atmospheric profile parameters by a meteorological radiosonde).There are some notable differences between SONARs and RADARs. SONARs are mainly used to produce the bathymetry of the sea, while remote sensing techniques focus more on identification of the materials properties than on its height.Echo-sounders (single or multi-beam) can be compared to Airborne optical maser Scanning both of them create point (vector) data containing X, Y, Z that need to be further processed in order to remove noise (spikes). An added complexity when dealing with bathymetry (as opposed to topography) is the need for tide corrections. some other major difference is that in remote sensing the results of the analysis can be compared easily to the field (aerial photos, maps, field measurements), while in SONAR the underlying bottom of the sea is hidden from us, and we depend totally on the data gathered.1.1.6 GIS GIS is a combination of hardware and software that enables The collection of spatial data from distinct sources (remote sensing being one of them). It relates spatial/tabular data, performs spacial/tabular analysis, and designs the layout of a map.A GIS software can accost both vector and raster data. Remote sensing data belong to the raster type and usually require special data manipulation procedures that a unbendable GIS does not offer. However, after a remote sensing analysis has been done, its results are usually combined within a GIS or into a database of an area for further analysis (possibly over laying with other layers). In the last few years, more and more vector capabilities have been added to remote sensing software, and some remote sensing functions are inserted into GIS modules.General Remote Sensing ApplicationsEach application itself has specific demands for spectral resolution, spatial resolution, and temporal resolution of the satellite sensor. There can be many applications for remote sensing in different fields. Some of them are described below.1.2.1 AgricultureAgriculture plays a dominant role in the economies of both developed and undeveloped countries. Satellite and airborne images are used as mapping tools to classify influences, meditate their health, examine their viability, and monitor farming practices. Agricultural applications of remote sensing take on crop type classification, crop condition assessment, crop pay estimation, mapping of soil characteristics, mapping of soil management practices, and compliance monitoring (farming practices).1.2.2 Fo restryForests are a valuable resource for providing food, shelter, wildlife home ground, fuel, and daily supplies (such as medicinal ingredients and paper). Forests play an important role in balancing the earths CO2 supply and exchange, acting as a key link between the atmosphere, geosphere, and hydrosphere. Forestry applications of remote sensing intromit the avocationReconnaissance mapping Objectives to be met by national environment agencies take forest cover updating, depletion monitoring, and measuring biophysical properties of forest stands.Commercial forestry Of importance to commercial forestry companies and to resource management agencies are inventory and mapping applications. These imply collecting harvest information, updating inventory information for timber supply, broad forest type, vegetation density, and biomass measurements.Environmental monitoring Conservation authorities are concerned with monitoring the quantity, health, and diversity of the earths forests. 1.2.3 GeologyGeology involves the study of landforms, structures, and the subsurface to understand physical processes that create and modify the earths crust. It is most commonly understood as the exploration and exploitation of mineral/hydrocarbon resources to improve the standard of living in society. geological applications of remote sensing include the following Bedrock mapping, lithological mapping, structural mapping, sand and gravel exploration/ exploitation, mineral exploration, hydrocarbon exploration, environmental geology, geobotany, baseline infrastructure, sedimentation monitoring, display case/monitoring, geo-hazard mapping, and planetary mapping.1.2.4 HydrologyHydrology is the study of water on the earths surface, whether flowing above ground, set in ice or snow, or retained by soil. Examples of hydrological applications include wetlands monitoring, soil moisture estimation, snow pack monitoring, measuring snow thickness, determine the snow-water equivalent, ice mon itoring, flood monitoring, glacier dynamics monitoring (surges, ablation), river/delta change detection, drainage catchment basin mapping, watershed modelling, irrigation canal leakage detection, and irrigation scheduling.1.2.5 Sea IceIce covers a substantial part of the earths surface and is a major factor in commercial fishing/shipping industries, Coast Guard operations, and global humour change studies. Examples of sea ice information and applications include ice concentration, ice type/age/motion, iceberg detection, surface topographytactical identification of leads, navigation, sound shipping routes, ice condition, historical ice, iceberg conditions, dynamics for planning purposes, wildlife habitat, pollution monitoring, and meteorological change research.1.2.6 consume Cover and Land UseAlthough the legal injury land cover and land uses are often used interchangeably, their factual meanings are quite distinct. Land cover refers to the surface cover on the ground, while l and use refers to the purpose the land serves. The properties measured with remote sensing techniques relate to land cover from which land use can be inferred, particularly with ancillary data or a priori knowledge.Land use applications of remote sensing include natural resource management, wildlife habitat protection, baseline mapping for GIS input, urban expansion, logistics planning for seismic/exploration/resource extraction activities, damage delineation (tornadoes, flooding, volcanic, seismic, fire), legal boundaries for tax/property evaluation, target detection, and identification of landing strips, roads, clearings, bridges, and land/water interface.1.2.7 MappingMapping constitutes an intrinsic component of the process of managing land resources, with mapped information the common product of the analysis of remotely sensed data.Mapping applications of remote sensing include the followingPlanimetry Land surveying techniques accompanied by the use of a GPS can be used to meet high accuracy requirements, but limitations include cost effectiveness and difficulties in attempting to map large or remote areas. Remote sensing provides a means of identifying planimetric data in an efficacious manner, so imagery is available in varying scales to meet the requirements of many different users. Defence applications typify the scope of planimetry applications, such as extracting conveyance route information, building/facilities locations, urban infrastructure, and general land cover.Digital elevation models (DEMs) Generating DEMs from remotely sensed data can be cost effective and efficient. A variety of sensors and methodologies to generate such models are available for mapping applications. Two primary methods of generating elevation data are stereogrammetry techniques using airphotos (photogrammetry), VIR imagery, radar data (radargrammetry), and radar interferometry.Baseline topographic mapping As a base map, imagery provides ancillary information to the extr acted planimetric detail. Sensitivity to surface nerve makes radar a useful tool for creating base maps and providing reconnaissance abilities for hydrocarbon/mineralogical companies manifold in exploration activities. This is particularly true in remote Yankee regions where vegetation cover does not mask the microtopography and where information may be sparse.1.2.8 Oceans Coastal MonitoringThe oceans provide valuable food-biophysical resources, serve as transferral routes, are crucially important in weather system formation and CO2 storage, and are an important link in the earths hydrological balance. Coastlines are environmentally sensitive interfaces between the ocean and land, and they respond to changes brought about by scotch development and changing land-use patterns. Often coastlines are also biologically diverse inter-tidal zones and can be highly urbanized. Ocean applications of remote sensing include the followingOcean pattern identificationCurrents, regional circu lation patterns, shears, frontal zones, midland waves, gravity waves, eddies, upwelling zones, and shallow water bathymetry.Storm forecasting Wind and wave retrieval.Fish stock and marine mammal assessment Water temperature monitoring, water quality, ocean productivity, phytoplankton concentration, drift,aquaculture inventory, and monitoring.Oil spill Predicting the oil spill extent and drift, strategical support for oil spill emergency response decisions, and identification of natural oil seepage areas for exploration.ShippingNavigation routing, traffic density studies, in operation(p) fisheries surveillance, and near-shore bathymetry mapping.General Observations on Remote Sensing in GeographyHiggitt Warburton (1999) have argued that remote sensing techniques provide fresh insights in geography in four main waysThey provide new applications for geography.They provide new and improved accuracy of measurement.They provide new data that allow the investigation of ideas that were p reviously untestable.They involve the development of data processing capability.Application of Remote Sensing in GeographyGeographic applications of remotely sensed data typically take one of four explanatory formsRemote sensing images have specific uses within several(a) fields of geographical study.Remote sensing data possess advantages over conventional data and can provide multispectral, multidata, and multisensor information. This data is very useful in the agrarian fields for the crop type classification, crop condition assessment, crop yield estimation, and soil mapping.In geology, remote sensing can be applied to analyze large, remote areas. Remote sensing interpretation also makes it lento for geologists to identify an areas rock types, geomorphology, and changes from natural events such as a flood, erosion, or landslide.The interpretation of remote sensing images allows physical- and biogeographers, ecologists, agricultural researchers, and foresters to easily detect wha t vegetation is present in certain areas, its growth potential, and sometimes what conditions are contributive to its being there.Additionally, those studying urban land use applications are also concerned with remote sensing because it allows them to easily pick out which land uses are present in an area. This can then be used as data in city planning applications and in the study of species habitat.ConclusionRemote sensing data has proven to be an important tool in geography. Multi-temporal satellite data help to delineate the various(a) change of the earth surface. Remote sensing has progressively expended applications in various fields such as urban-regional planning, utilities planning, health planning, geomorphology, and resource planning. Because of its varied applications and ability to allow users to collect, interpret, and manipulate data over dangerous areas, remote sensing has become a useful tool for all geographers, regardless of their concentration.