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50-611: The Awatere Fault is an active dextral (right lateral) strike-slip fault in the northeastern part of South Island , New Zealand . It forms part of the Marlborough fault system , which accommodates the transfer of displacement along the oblique convergent boundary between the Indo-Australian plate and Pacific plate , from the transform Alpine Fault to the Hikurangi Trough subduction zone . The 1848 Marlborough earthquake

100-690: A degree or two with electronic compasses. Compasses can measure not just azimuth (i. e. degrees to magnetic north), but also altitude (degrees above the horizon), since the magnetic field curves into the Earth at different angles at different latitudes. More exact orientations require gyroscopic-aided orientation , periodically realigned by different methods including navigation from stars or known benchmarks. The quality of remote sensing data consists of its spatial, spectral, radiometric and temporal resolutions. In order to create sensor-based maps, most remote sensing systems expect to extrapolate sensor data in relation to

150-554: A great deal of data handling overhead. These data tend to be generally more useful for many applications. The regular spatial and temporal organization of Level 3 datasets makes it feasible to readily combine data from different sources. While these processing levels are particularly suitable for typical satellite data processing pipelines, other data level vocabularies have been defined and may be appropriate for more heterogeneous workflows. Satellite images provide very useful information to produce statistics on topics closely related to

200-825: A large extent of geography. At the same time, the data is often complex to interpret, and bulky to store. Modern systems tend to store the data digitally, often with lossless compression . The difficulty with this approach is that the data is fragile, the format may be archaic, and the data may be easy to falsify. One of the best systems for archiving data series is as computer-generated machine-readable ultrafiche , usually in typefonts such as OCR-B , or as digitized half-tone images. Ultrafiches survive well in standard libraries, with lifetimes of several centuries. They can be created, copied, filed and retrieved by automated systems. They are about as compact as archival magnetic media, and yet can be read by human beings with minimal, standardized equipment. Generally speaking, remote sensing works on

250-484: A legend of mapped classes that suits our purpose, taking again the example of wheat. The straightforward approach is counting the number of pixels classified as wheat and multiplying by the area of each pixel. Many authors have noticed that estimator is that it is generally biased because commission and omission errors in a confusion matrix do not compensate each other The main strength of classified satellite images or other indicators computed on satellite images

300-472: A reference point including distances between known points on the ground. This depends on the type of sensor used. For example, in conventional photographs, distances are accurate in the center of the image, with the distortion of measurements increasing the farther you get from the center. Another factor is that of the platen against which the film is pressed can cause severe errors when photographs are used to measure ground distances. The step in which this problem

350-679: A sample with less accurate, but exhaustive, data for a covariable or proxy that is cheaper to collect. For agricultural statistics, field surveys are usually required, while photo-interpretation may better for land cover classes that can be reliably identified on aerial photographs or high resolution satellite images. Additional uncertainty can appear because of imperfect reference data (ground truth or similar). Some options are: ratio estimator , regression estimator , calibration estimators and small area estimators If we target other variables, such as crop yield or leaf area , we may need different indicators to be computed from images, such as

400-698: Is an accepted version of this page Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation . The term is applied especially to acquiring information about Earth and other planets . Remote sensing is used in numerous fields, including geophysics , geography , land surveying and most Earth science disciplines (e.g. exploration geophysics , hydrology , ecology , meteorology , oceanography , glaciology , geology ). It also has military, intelligence, commercial, economic, planning, and humanitarian applications, among others. In current usage,

450-724: Is considered to be a geologic hazard – one related to earthquakes as a cause. Effects of movement on an active fault include strong ground motion , surface faulting, tectonic deformation , landslides and rockfalls , liquefaction , tsunamis , and seiches . Quaternary faults are those active faults that have been recognized at the surface and which have evidence of movement during the Quaternary Period. Related geological disciplines for active-fault studies include geomorphology , seismology , reflection seismology , plate tectonics , geodetics and remote sensing , risk analysis , and others. Active faults tend to occur in

500-562: Is detected by the sensor) and "passive" remote sensing (when the reflection of sunlight is detected by the sensor). Remote sensing can be divided into two types of methods: Passive remote sensing and Active remote sensing. Passive sensors gather radiation that is emitted or reflected by the object or surrounding areas. Reflected sunlight is the most common source of radiation measured by passive sensors. Examples of passive remote sensors include film photography , infrared , charge-coupled devices , and radiometers . Active collection, on

550-553: Is employed with other factors to determine the potential earthquake hazard. The geologic conditions and plate tectonic setting in much of the Western U.S. has resulted in the region being underlain by relatively thin crust and having high heat flow, both of which can favor relatively high deformation rates and active faulting. In contrast, in the Central and Eastern U.S. (CEUS) the crust is thicker, colder, older, and more stable. Furthermore,

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600-604: Is impossible to directly measure temperatures in the upper atmosphere, it is possible to measure the spectral emissions from a known chemical species (such as carbon dioxide) in that region. The frequency of the emissions may then be related via thermodynamics to the temperature in that region. To facilitate the discussion of data processing in practice, several processing "levels" were first defined in 1986 by NASA as part of its Earth Observing System and steadily adopted since then, both internally at NASA (e. g., ) and elsewhere (e. g., ); these definitions are: A Level 1 data record

650-418: Is providing cheap information on the whole target area or most of it. This information usually has a good correlation with the target variable (ground truth) that is usually expensive to observe in an unbiased and accurate way. Therefore it can be observed on a probabilistic sample selected on an area sampling frame . Traditional survey methodology provides different methods to combine accurate information on

700-450: Is relevant to highlight that probabilistic sampling is not critical for the selection of training pixels for image classification, but it is necessary for accuracy assessment of the classified images and area estimation. Additional care is recommended to ensure that training and validation datasets are not spatially correlated. We suppose now that we have classified images or a land cover map produced by visual photo-interpretation, with

750-432: Is resolved is called georeferencing and involves computer-aided matching of points in the image (typically 30 or more points per image) which is extrapolated with the use of an established benchmark, "warping" the image to produce accurate spatial data. As of the early 1990s, most satellite images are sold fully georeferenced. In addition, images may need to be radiometrically and atmospherically corrected. Interpretation

800-489: Is that of examined areas or objects that reflect or emit radiation that stand out from surrounding areas. For a summary of major remote sensing satellite systems see the overview table. To coordinate a series of large-scale observations, most sensing systems depend on the following: platform location and the orientation of the sensor. High-end instruments now often use positional information from satellite navigation systems . The rotation and orientation are often provided within

850-402: Is that of increasingly smaller sensor pods such as those used by law enforcement and the military, in both manned and unmanned platforms. The advantage of this approach is that this requires minimal modification to a given airframe. Later imaging technologies would include infrared, conventional, Doppler and synthetic aperture radar. The development of artificial satellites in the latter half of

900-440: Is the critical process of making sense of the data. The first application was that of aerial photographic collection which used the following process; spatial measurement through the use of a light table in both conventional single or stereographic coverage, added skills such as the use of photogrammetry, the use of photomosaics, repeat coverage, Making use of objects' known dimensions in order to detect modifications. Image Analysis

950-560: Is the most fundamental (i. e., highest reversible level) data record that has significant scientific utility, and is the foundation upon which all subsequent data sets are produced. Level 2 is the first level that is directly usable for most scientific applications; its value is much greater than the lower levels. Level 2 data sets tend to be less voluminous than Level 1 data because they have been reduced temporally, spatially, or spectrally. Level 3 data sets are generally smaller than lower level data sets and thus can be dealt with without incurring

1000-424: Is the recently developed automated computer-aided application that is in increasing use. Object-Based Image Analysis (OBIA) is a sub-discipline of GIScience devoted to partitioning remote sensing (RS) imagery into meaningful image-objects, and assessing their characteristics through spatial, spectral and temporal scale. Old data from remote sensing is often valuable because it may provide the only long-term data for

1050-598: The Amazon Basin , glacial features in Arctic and Antarctic regions, and depth sounding of coastal and ocean depths. Military collection during the Cold War made use of stand-off collection of data about dangerous border areas. Remote sensing also replaces costly and slow data collection on the ground, ensuring in the process that areas or objects are not disturbed. Orbital platforms collect and transmit data from different parts of

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1100-1013: The EGU or Digital Earth encourage the development of learning modules and learning portals . Examples include: FIS – Remote Sensing in School Lessons , Geospektiv , Ychange , or Spatial Discovery, to promote media and method qualifications as well as independent learning. Remote sensing data are processed and analyzed with computer software, known as a remote sensing application . A large number of proprietary and open source applications exist to process remote sensing data. There are applications of gamma rays to mineral exploration through remote sensing. In 1972 more than two million dollars were spent on remote sensing applications with gamma rays to mineral exploration. Gamma rays are used to search for deposits of uranium. By observing radioactivity from potassium, porphyry copper deposits can be located. A high ratio of uranium to thorium has been found to be related to

1150-547: The European Commission . Forest area and deforestation estimation have also been a frequent target of remote sensing projects, the same as land cover and land use Ground truth or reference data to train and validate image classification require a field survey if we are targetting annual crops or individual forest species, but may be substituted by photointerpretation if we look at wider classes that can be reliably identified on aerial photos or satellite images. It

1200-571: The Magellan spacecraft provided detailed topographic maps of Venus , while instruments aboard SOHO allowed studies to be performed on the Sun and the solar wind , just to name a few examples. Recent developments include, beginning in the 1960s and 1970s, the development of image processing of satellite imagery . The use of the term "remote sensing" began in the early 1960s when Evelyn Pruitt realized that advances in science meant that aerial photography

1250-527: The MetOp spacecraft of EUMETSAT are all operated at altitudes of about 800 km (500 mi). The Proba-1 , Proba-2 and SMOS spacecraft of European Space Agency are observing the Earth from an altitude of about 700 km (430 mi). The Earth observation satellites of UAE, DubaiSat-1 & DubaiSat-2 are also placed in Low Earth orbits (LEO) orbits and providing satellite imagery of various parts of

1300-533: The NDVI , a good proxy to chlorophyll activity. The modern discipline of remote sensing arose with the development of flight. The balloonist G. Tournachon (alias Nadar ) made photographs of Paris from his balloon in 1858. Messenger pigeons, kites, rockets and unmanned balloons were also used for early images. With the exception of balloons, these first, individual images were not particularly useful for map making or for scientific purposes. Systematic aerial photography

1350-615: The electromagnetic spectrum , which in conjunction with larger scale aerial or ground-based sensing and analysis, provides researchers with enough information to monitor trends such as El Niño and other natural long and short term phenomena. Other uses include different areas of the earth sciences such as natural resource management , agricultural fields such as land usage and conservation, greenhouse gas monitoring , oil spill detection and monitoring, and national security and overhead, ground-based and stand-off collection on border areas. The basis for multispectral collection and analysis

1400-613: The 20th century allowed remote sensing to progress to a global scale as of the end of the Cold War. Instrumentation aboard various Earth observing and weather satellites such as Landsat , the Nimbus and more recent missions such as RADARSAT and UARS provided global measurements of various data for civil, research, and military purposes. Space probes to other planets have also provided the opportunity to conduct remote sensing studies in extraterrestrial environments, synthetic aperture radar aboard

1450-528: The CEUS is thousands of miles from active plate boundaries, so the rates of deformation are low in this region. Nevertheless, the CEUS has had some rather large earthquakes in historical times, including a series of major earthquakes near New Madrid, Missouri in 1811–1812 , a large earthquake near Charleston, South Carolina in 1886, and the Cape Ann earthquake northeast of Boston in 1755. Remote sensing This

1500-474: The German students use the services of Google Earth ; in 2006 alone the software was downloaded 100 million times. But studies have shown that only a fraction of them know more about the data they are working with. There exists a huge knowledge gap between the application and the understanding of satellite images. Remote sensing only plays a tangential role in schools, regardless of the political claims to strengthen

1550-634: The coast, near White Bluffs, without significant segmentation. Shallow-crust seismic studies in Cook Strait extend the fault about 20 km (12 mi) beyond White Bluffs into Cook Strait . The Awatere River , occupying the Awatere Valley, follows the trace of much of the eastern section of the fault, giving its name to the whole structure. The Molesworth section appears to have moved twice since about 3000 years ago, in events with slip values of about 6–7 m (20–23 ft). Trenching at Saxton River at

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1600-495: The discovery of the Earth's Van Allen radiation belts . The TIROS-1 spacecraft, launched on April 1, 1960, as part of NASA's Television Infrared Observation Satellite (TIROS) program, sent back the first television footage of weather patterns to be taken from space. In 2008, more than 150 Earth observation satellites were in orbit, recording data with both passive and active sensors and acquiring more than 10 terabits of data daily. By 2021, that total had grown to over 950, with

1650-454: The eastern end of the Molesworth section suggests 8 ruptures since about 6,300 years ago, with an estimated mean recurrence of about 800 years. Evidence from the eastern section of the fault suggests that there were 9–10 earthquakes in the period from 8610 BP to AD 1848. This gives a mean recurrence interval of 820–950 years. In 1848 a minimum 110 km (68 mi) length section of

1700-625: The farmer who plants his fields in a remote corner of the country knows its value." The development of remote sensing technology reached a climax during the Cold War with the use of modified combat aircraft such as the P-51 , P-38 , RB-66 and the F-4C , or specifically designed collection platforms such as the U2/TR-1 , SR-71 , A-5 and the OV-1 series both in overhead and stand-off collection. A more recent development

1750-586: The fault ruptured, causing an earthquake of an estimated magnitude of about 7.5 M w . It is possible that up to 140 km (87 mi) of the fault ruptured. The rupture appears to have bypassed the Molesworth section of the fault, continuing on the southern strand through Barefell Pass. Seismic hazard on the Eastern section is considered low, with only about 150 years since the last major earthquake on that section and an estimated recurrence interval of 600–2500 years. Active fault Active faulting

1800-417: The fields of media and methods apart from the mere visual interpretation of satellite images. Many teachers have great interest in the subject "remote sensing", being motivated to integrate this topic into teaching, provided that the curriculum is considered. In many cases, this encouragement fails because of confusing information. In order to integrate remote sensing in a sustainable manner organizations like

1850-581: The first commercial satellite (IKONOS) collecting very high resolution imagery was launched. Remote Sensing has a growing relevance in the modern information society. It represents a key technology as part of the aerospace industry and bears increasing economic relevance – new sensors e.g. TerraSAR-X and RapidEye are developed constantly and the demand for skilled labour is increasing steadily. Furthermore, remote sensing exceedingly influences everyday life, ranging from weather forecasts to reports on climate change or natural disasters . As an example, 80% of

1900-472: The junction between the Alpine and Wairau Faults near Lake Tennyson, to near Molesworth Station in the northeast. It is about 55 km (34 mi) in length and consists of several smaller segments. This section has an overall strike of N75–80°E, giving local zones of transtension at some of the segment boundaries, such as at Isolated Flat. The Eastern section of the fault runs from Molesworth Station to

1950-461: The largest number of satellites operated by US-based company Planet Labs . Most Earth observation satellites carry instruments that should be operated at a relatively low altitude. Most orbit at altitudes above 500 to 600 kilometers (310 to 370 mi). Lower orbits have significant air-drag , which makes frequent orbit reboost maneuvers necessary. The Earth observation satellites ERS-1, ERS-2 and Envisat of European Space Agency as well as

2000-459: The launch of the first artificial satellite, Sputnik 1 , by the Soviet Union on October 4, 1957. Sputnik 1 sent back radio signals, which scientists used to study the ionosphere . The United States Army Ballistic Missile Agency launched the first American satellite, Explorer 1 , for NASA's Jet Propulsion Laboratory on January 31, 1958. The information sent back from its radiation detector led to

2050-522: The other hand, emits energy in order to scan objects and areas whereupon a sensor then detects and measures the radiation that is reflected or backscattered from the target. RADAR and LiDAR are examples of active remote sensing where the time delay between emission and return is measured, establishing the location, speed and direction of an object. Remote sensing makes it possible to collect data of dangerous or inaccessible areas. Remote sensing applications include monitoring deforestation in areas such as

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2100-848: The presence of hydrothermal copper deposits. Radiation patterns have also been known to occur above oil and gas fields, but some of these patterns were thought to be due to surface soils instead of oil and gas. An Earth observation satellite or Earth remote sensing satellite is a satellite used or designed for Earth observation (EO) from orbit , including spy satellites and similar ones intended for non-military uses such as environmental monitoring , meteorology , cartography and others. The most common type are Earth imaging satellites, that take satellite images , analogous to aerial photographs ; some EO satellites may perform remote sensing without forming pictures, such as in GNSS radio occultation . The first occurrence of satellite remote sensing can be dated to

2150-412: The principle of the inverse problem : while the object or phenomenon of interest (the state ) may not be directly measured, there exists some other variable that can be detected and measured (the observation ) which may be related to the object of interest through a calculation. The common analogy given to describe this is trying to determine the type of animal from its footprints. For example, while it

2200-423: The support for teaching on the subject. A lot of the computer software explicitly developed for school lessons has not yet been implemented due to its complexity. Thereby, the subject is either not at all integrated into the curriculum or does not pass the step of an interpretation of analogue images. In fact, the subject of remote sensing requires a consolidation of physics and mathematics as well as competences in

2250-406: The term remote sensing generally refers to the use of satellite - or aircraft-based sensor technologies to detect and classify objects on Earth. It includes the surface and the atmosphere and oceans , based on propagated signals (e.g. electromagnetic radiation ). It may be split into "active" remote sensing (when a signal is emitted by a satellite or aircraft to the object and its reflection

2300-615: The territory, such as agriculture, forestry or land cover in general. The first large project to apply Landsata 1 images for statistics was LACIE (Large Area Crop Inventory Experiment), run by NASA, NOAA and the USDA in 1974–77. Many other application projects on crop area estimation have followed, including the Italian AGRIT project and the MARS project of the Joint Research Centre (JRC) of

2350-591: The vicinity of tectonic plate boundaries, and active fault research has focused on these regions. Active faults tend to occur less within the area of any given plate. The fact that intraplate regions may also present seismic hazards has only recently been recognized. Various geologic methods are used to define the boundaries of an active fault such as remote sensing and magnetic measurements, as well as other ways. Several types of data, such as seismologic reports or records over time, are used to gauge fault activity. Activity and fault area are correlated, and risk analysis

2400-541: Was caused by rupture of the whole of the eastern section of the Awatere Fault. The 175 km (109 mi) long Awatere Fault is formed of two main segments; the Molesworth section to the southwest and the Eastern section to the northeast. A further strand links the southwestern end of the Eastern section to the Clarence Fault, passing through Barefell Pass. The Molesworth segment of the Awatere Fault runs from close to

2450-579: Was developed for military surveillance and reconnaissance purposes beginning in World War I . After WWI, remote sensing technology was quickly adapted to civilian applications. This is demonstrated by the first line of a 1941 textbook titled "Aerophotography and Aerosurverying," which stated the following: "There is no longer any need to preach for aerial photography-not in the United States- for so widespread has become its use and so great its value that even

2500-548: Was no longer an adequate term to describe the data streams being generated by new technologies. With assistance from her fellow staff member at the Office of Naval Research, Walter Bailey, she coined the term "remote sensing". Several research groups in Silicon Valley including NASA Ames Research Center , GTE , and ESL Inc. developed Fourier transform techniques leading to the first notable enhancement of imagery data. In 1999

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