Remote sensing technique has surfaced as an efficient tool for organized survey, examination, and better management of natural resources (land, land, drinking water, forests, mountains) along with the monitoring of desertification, flood, drought, and landform change. It offers a vast scope to explore, identify, and review the natural sources of undeveloped areas. It documents the vibrant changes in physical processes and resulting landforms, usually by satellite tv images. This paper provides a standard overview of distant sensing. While this system has been applied to beaches, valleys, and other landforms, the main concern of this newspaper is its role in geography.
Key Words: Remote control Sensing, Geography, Application
Introduction
Despite advancements in physical studies, the methods of traditional geography have grown to be inadequate to apprehend its fact and intricacy, considering technical and technological changes which have happened within the last 30 years. However, this will not imply that these changes aren't useful for geographic research. This has become evident given that Geographical Information Systems (GIS) are expanding spatial studies to charm to such technology as remote sensing and computer sciences (MEC, 1999).
This paper focuses on a particular research tool for geographic research known as remote sensing. This benefits the study of geography in many ways, especially as a study tool, a tool for collecting high quality data, and an instrument that supports the reasoning process. It achieves these responsibilities by virtue of its spacial and temporal coverage (Rhoads, 2004; Doreen, 2009). Geographers progressively use remotely sensed data to obtain information about the earth's land surface, ocean, and atmosphere since it provides objective information at a variety of spatial scales (local to global), offers a synoptic view of the area appealing, allows access to distant/inaccessible sites, provides spectral information outside the visible part of the electromagnetic range, and facilitates studies of how features change over time. This data may be analyzed independently or in conjunction with other digital data levels (e. g. in a GIS).
General Summary of Remote Sensing
Although this paper is mainly worried about remote control sensing used for geography, the field of remote sensing is very extensive in data acquisition methods, data handling procedures, and different techniques and applications. Therefore, it pays to to provide a general summary about several important topics regarding remote sensing of the top of earth. The written text also attempts to give the reader an understanding of the functions and constraints of remote control sensing. Very few equations and formulas will be given in the written text, as the focus will be on understanding the essential ideas.
Remote sensing is defined according to certain functions. It requires acquiring the info associated with an object's property by the device not in touch with that thing under study. This calls for the utilization far away of any device for gathering information important to the surroundings, such as measurements of drive fields, electromagnetic rays, or acoustic energy for aircraft, spacecrafts, or ships. The technique uses such devices as a camcorders, lasers, radio frequency receivers, radar systems, sonars, seismographs, gravimeters, magnetometers, and scintillation counters. A few examples of distant sensing applications receive in the areas which have importance for the geographers. Because of the wide scope protected, the subjects could not be covered in detail and the interested audience should choose the relevant literature (Lillesand & Kiefer, 2000; Sabins, 2007; Jenson, 2007; Longley et. al. , 2005; Shukla & Pathak 2009).
As humans, we are intimately acquainted with remote sensing in that we rely on visual belief to provide us with a lot of the info about our environment. As receptors, however, our sight are greatly tied to level of sensitivity to only the visible range of electromagnetic energy, enjoying perspectives dictated by the location of our bodies, and the inability to create a prolonged record of everything we view. Due to these constraints, humans have continually sought to build up the technological means to increase our ability to track record the physical properties of the environment.
Beginning with the early use of aerial photography, remote control sensing has been recognized as a valuable tool for browsing, studying, characterizing, and making decisions about the environment. In the past few decades, remote sensing technology has advanced on three fronts: from predominantly armed forces uses to a number of environmental analysis applications that relate to land, ocean, and atmosphere issues; from analogue photographic systems to receptors that convert energy from many elements of the electromagnetic spectrum to electronic indicators; and from airplane to satellite websites.
1. 1 Modern Benefits of Remote Sensing
Remote sensing technology is now more important in geography scheduled to attention being paid to the latest information, planning, and management for public and private passions. It is most readily useful for natural learning resource management, lasting development, environmental degradation, and devastation management. Its satellite data are being used as basic inputs for the inventory of natural resources and development processes like agriculture, earth, forestry, and geology (Chavez et al. , 1977). There are other important solutions that exist to geographers as well, such as maps, aerial photography/photogrammetry/pictometry, SAR, LiDAR, SONAR, and GIS. The next section discusses the technologies mentioned above combined with the similarities and distinctions between them and the field of remote sensing.
1. 1. 1 Maps: Based on the International Cartographic Union, a map is "a conventionalised image representing decided on features or characteristics of geographical reality, suitable for use when spatial relationships are of primary importance. " This meaning declares that atlanta divorce attorneys map you can find scientific reliability and an activity of selection present (symbolization, abstraction, generalization). However, the International Cartographic Union gives that "a map shows us the earth as we know it, " and what we know is "an extremely complex subject that is made up of: The limitations of subject, technology, and our measurement tools; everything we believe that prevails; what we want to be important; and what we want and desire to. " Thus, a map is subjective, for we always determine what to placed on it as well as how to stand for it. A remote control sensing image, on the other hand, is an objective taking of the electromagnetic reaching the sensor. Another important difference is that a map is a projection of the planet earth on paper without the relief displacements, while in a remote sensing image it is just a projection of pain relief displacements and geometrical distortions.
1. 1. 2 Aerial Picture taking/Photogrammetry/Pictometry: These systems gather data about top of the surface of the planet earth by measuring the electromagnetic radiation from airborne systems. The major differences are detailed below:
Aerial photos are used by an analogue tool (the film of the photogrammetric camera), then scanned to be changed to digital press. The benefit of a film is its high res (granularity), as the good thing about the CCD is that people measure quantitatively the radiation achieving the sensor (radiance prices, rather than a gray-value level pub). Thus, remote sensing data can be built-into physical equations of energy-balance.
An aerial picture is a central projection, with the complete picture used at one case. A remote control sensing image is established line after collection, therefore the geometrical correction is a lot more complex, with each pixel needing to be cured as a central projection.
Aerial photos usually collect data only in the obvious spectrum, while distant sensing sensors can be designed to measure radiation across the electromagnetic spectrum.
Pictometry is the name of a copyrighted aerial image record procedure for the Pictometry International Corp. , USA. It produces imagery displaying the fronts and factors of objects and locations on the ground. Images are captured by low-flying airplanes, depicting up to 12 oblique perspectives as well as an orthogonal view of every location flown. These perspectives can then be stitched collectively to create amalgamated aerial maps that seamlessly cover large areas. Pictometry imagery can be overlaid with various form files because every pixel is georeferenced to its exact location on the planet earth. This allows pictometry imagery to be built-into many existing GIS software applications for use in many areas. Direct measurements can be produced on pictometry imagery which includes area, distance, elevation, elevation, pitch, and bearing (http://www. pictometry. com).
1. 1. 3 SAR: Synthetic Aperture Radar (SAR) provides imagery during evening or in bad weather as well as throughout the day. SAR images can be utilized for earth tool mapping and environmental monitoring, which require broad-area imaging at high resolutions. Synthetic aperture radar complements photographic and other optical imaging capacities as a result of least constraints on the time-of-day, atmospheric conditions, and unique responses of ground/cultural targets to radar frequencies.
Synthetic aperture radar technology provides ground structural information to geologists for nutrient exploration, olive oil spill boundaries on normal water to environmentalists, ice threat maps to navigators, and reconnaissance-targeting information to military operations.
1. 1. 4 LiDAR: Light Detection and Ranging (LiDAR) is another strategy that offers several advantages over the conventional methods of topographic data collection. This system provides data with higher density, higher exactness, less time for data processing, light self-reliance, and minimum surface control things required. Due to these characteristics, LiDAR is complementing normal techniques in some applications while completely swapping them in a number of others. Various applications where LiDAR data are being used are geomorphology, glacier studies, forest biomass mapping, and era of the digital elevation model.
1. 1. 5 SONAR: The SONAR can also be considered as remote sensing by learning the floors of the ocean (bathymetry and sea bed features) from a distance. The SONAR can be an active kind of remote control sensing but with sound waves rather than electromagnetic rays (like Radar, it generally does not rely upon an external source of waves). Both systems transfer waves through an interfering medium (normal water, air) that adds noise to the data. For corrections, these must be applied to the organic data accumulated. In remote sensing, however, RADAR is regarded as almost weather-independent, and atmospheric disruptions have an effect on mainly passive distant sensing. To create these necessary corrections, both systems be based upon calibration from field data (whether it be salinity, temp, pressure assessed by the ship while surveying, or measurements of the atmospheric profile parameters by a meteorological radiosonde).
There are some distinctive dissimilarities between SONARs and RADARs. SONARs are mainly utilized to produce the bathymetry of the sea, while distant sensing techniques concentrate more on identification of the material's properties than on its elevation. Echo-sounders (sole or multi-beam) can be in comparison to Airborne Laser Scanning - both of these create point (vector) data formulated with X, Y, Z that require to be further refined in order to eliminate noise (spikes). An added complexity when interacting with bathymetry (as opposed to topography) is the necessity for tide corrections.
Another major difference is that in distant sensing the results of the research can be likened easily to the field (aerial photos, maps, field measurements), while in SONAR the actual bottom of the sea is concealed from us, and we depend totally on the info gathered.
1. 1. 6 GIS: GIS is a mixture of hardware and software that allows: The collection of spatial data from different sources (remote control sensing being one of them). It relates spatial/tabular data, performs spacial/tabular examination, and designs the layout of an map.
A GIS software can handle both vector and raster data. Remote sensing data belong to the raster type and usually require special data manipulation strategies a regular GIS does not offer. However, following a remote sensing research has been done, its results are usually combined within the GIS or into a data source of a location for further examination (possibly overlaying with other tiers). In the last few years, more and more vector capabilities have been put into remote sensing software, plus some remote sensing functions are put into GIS modules.
General Remote Sensing Applications:
Each request itself has specific requirements for spectral image resolution, spatial quality, and temporal resolution of the satellite sensor. There can be many applications for distant sensing in different fields. A few of them are detailed below.
1. 2. 1 Agriculture:
Agriculture takes on a dominating role in the economies of both developed and undeveloped countries. Satellite and airborne images are being used as mapping tools to classify vegetation, verify their health, verify their viability, and screen farming tactics. Agricultural applications of distant sensing include crop type classification, crop condition examination, crop yield estimation, mapping of ground characteristics, mapping of land management procedures, and conformity monitoring (farming procedures).
1. 2. 2 Forestry:
Forests are a valuable source of information for providing food, shelter, wildlife habitat, gasoline, and daily products (such as medicinal ingredients and newspaper). Forests play an important role in controlling the earth's CO2 source and exchange, performing as an integral link between your atmosphere, geosphere, and hydrosphere. Forestry applications of remote sensing are the following:
Reconnaissance mapping: Objectives to be fulfilled by national environment agencies include forest cover upgrading, depletion monitoring, and measuring biophysical properties of forest stands.
Commercial forestry: Of importance to commercial forestry companies also to resource management companies are inventory and mapping applications. Included in these are collecting harvest information, upgrading inventory information for timber supply, broad forest type, vegetation density, and biomass measurements.
Environmental monitoring: Conservation specialists are worried with monitoring the number, health, and variety of the earth's forests.
1. 2. 3 Geology:
Geology involves the study of landforms, buildings, and the subsurface to understand physical processes that induce and improve the earth's crust. It really is most commonly recognized as the exploration and exploitation of nutrient/hydrocarbon resources to improve the standard of surviving in society.
Geological applications of remote sensing are the pursuing: Bedrock mapping, lithological mapping, structural mapping, fine sand and gravel exploration/ exploitation, mineral exploration, hydrocarbon exploration, environmental geology, geobotany, baseline infrastructure, sedimentation monitoring, event/monitoring, geo-hazard mapping, and planetary mapping.
1. 2. 4 Hydrology:
Hydrology is the analysis of normal water on the earth's surface, whether flowing above ground, freezing in snow or snow, or maintained by soil. Types of hydrological applications include wetlands monitoring, earth water estimation, snow pack monitoring, calculating snow thickness, deciding the snow-water equivalent, ice monitoring, overflow monitoring, glacier dynamics monitoring (surges, ablation), river/delta change detection, drainage basin mapping, watershed modelling, irrigation canal leakage recognition, and irrigation arranging.
1. 2. 5 Sea Snow:
Ice covers a considerable area of the earth's surface and it is a major element in commercial angling/shipping industries, Coastline Guard operations, and global environment change studies. Types of sea glaciers information and applications include ice concentration, glaciers type/age/motion, iceberg diagnosis, surface topography tactical identification of leads, navigation, safe shipment routes, glaciers condition, historical glaciers, iceberg conditions, dynamics for planning purposes, animals habitat, pollution monitoring, and meteorological change research.
1. 2. 6 Land Cover and Land Use:
Although the terms 'land cover' and 'land uses' are often used interchangeably, their actual meanings are very specific. Land cover refers to the surface cover on the ground, while land use refers to the reason the land acts. The properties measured with distant sensing techniques relate to land cover that land use can be inferred, particularly with ancillary data or a priori knowledge.
Land use applications of remote control sensing include natural tool management, animals habitat cover, baseline mapping for GIS type, urban development, logistics planning seismic/exploration/resource removal activities, damage delineation (tornadoes, flooding, volcanic, seismic, flame), legal restrictions for tax/property evaluation, concentrate on detection, and recognition of landing pieces, roads, clearings, bridges, and land/drinking water interface.
1. 2. 7 Mapping:
Mapping constitutes an intrinsic component of the procedure of managing land resources, with mapped information the common product of the examination of remotely sensed data.
Mapping applications of remote control sensing are the following:
· Planimetry: Land surveying techniques supported through a GPS can be used to meet high precision requirements, but constraints include cost effectiveness and difficulties in wanting to map large or remote control areas. Remote control sensing offers a means of identifying planimetric data in an effective manner, so imagery comes in varying scales to meet the requirements of several different users. Defence applications typify the scope of planimetry applications, such as extracting transportation road information, building/facilities locations, urban infrastructure, and basic 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 key methods of making elevation data are stereogrammetry techniques using airphotos (photogrammetry), VIR imagery, radar data (radargrammetry), and radar interferometry.
· Baseline topographic mapping: Like a platform map, imagery provides ancillary information to the extracted planimetric depth. Sensitivity to surface expression makes radar a useful tool for creating bottom maps and providing reconnaissance abilities for hydrocarbon/mineralogical companies involved with exploration activities. That is particularly true in remote control northern areas where vegetation cover does not face mask the microtopography and where information may be sparse.
The oceans provide valuable food-biophysical resources, help as travelling routes, are crucially important in weather system formation and CO2 safe-keeping, and are an important website link in the earth's hydrological balance. Coastlines are environmentally delicate interfaces between the sea and land, plus they react to changes as a result of monetary development and changing land-use habits. Often coastlines are also biologically diverse inter-tidal areas and can be highly urbanized. Ocean applications of remote sensing include the following:
· Ocean style id: Currents, regional circulation patterns, shears, frontal areas, internal waves, gravity waves, eddies, upwelling zones, and shallow normal water bathymetry.
· Storm forecasting: Wind and influx retrieval.
· Seafood stock and marine mammal examination: Water temps monitoring, normal water quality, ocean output, phytoplankton attentiveness, drift, aquaculture inventory, and monitoring.
· Engine oil spill: Predicting the petrol spill degree and drift, tactical support for olive oil spill crisis response decisions, and recognition of natural essential oil seepage areas for exploration.
· Shipping and delivery: Navigation routing, traffic denseness studies, operational fisheries surveillance, and near-shore bathymetry mapping.
General Observations on Universal remote Sensing in Geography
Higgitt & Warburton (1999) have argued that remote sensing techniques provide fresh insights in geography in four main ways:
They provide new applications for geography.
They provide new and improved upon accuracy of dimension.
They provide new data that permit the research of ideas which were recently untestable.
They involve the development of data processing functionality.
Application of Remote Sensing in Geography
Geographic applications of remotely sensed data typically take one of four explanatory varieties:
Remote sensing images have specific uses within various fields of geographical analysis.
Remote sensing data have got advantages over regular data and can provide multispectral, multidata, and multisensor information. This data is very useful in the agricultural fields for the crop type classification, crop condition analysis, crop produce estimation, and dirt mapping.
In geology, distant sensing can be employed to analyze large, distant areas. Far off sensing interpretation also helps it be easy for geologists to recognize an area's rock and roll types, geomorphology, and changes from natural happenings like a overflow, erosion, or landslide.
The interpretation of distant sensing images allows physical- and biogeographers, ecologists, agricultural analysts, and foresters to easily identify what vegetation exists using areas, its growth potential, and sometimes what conditions are conducive to its being there.
Additionally, those studying metropolitan land use applications are also worried about remote sensing since it allows those to easily choose which land uses can be found in an area. This can then be utilized as data in city planning applications and in the study of kinds habitat.
Conclusion
Remote sensing data has shown to be an important tool in geography. Multi-temporal satellite television data help delineate the many change of the earth surface. Universal remote sensing has progressively expended applications in a variety of domains such as urban-regional planning, utilities planning, health planning, geomorphology, and source planning. Due to its numerous applications and capability to allow users to get, interpret, and manipulate data over dangerous areas, remote control sensing has become a useful tool for many geographers, no matter their awareness.
