90-652: The Suomi National Polar-orbiting Partnership ( Suomi NPP ), previously known as the National Polar-orbiting Operational Environmental Satellite System Preparatory Project ( NPP ) and NPP-Bridge , is a weather satellite operated by the United States National Oceanic and Atmospheric Administration (NOAA). It was launched in 2011 and is currently in operation. Suomi NPP was originally intended as
180-529: A 1 MOA rifle should be capable, under ideal conditions, of repeatably shooting 1-inch groups at 100 yards. Most higher-end rifles are warrantied by their manufacturer to shoot under a given MOA threshold (typically 1 MOA or better) with specific ammunition and no error on the shooter's part. For example, Remington's M24 Sniper Weapon System is required to shoot 0.8 MOA or better, or be rejected from sale by quality control . Rifle manufacturers and gun magazines often refer to this capability as sub-MOA , meaning
270-424: A turn, or complete rotation , one arcminute is 1 / 21 600 of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth's circumference is very near 21 600 nmi . A minute of arc is π / 10 800 of a radian . A second of arc , arcsecond (arcsec), or arc second , denoted by
360-495: A visual angle of one minute of arc, from a distance of twenty feet . A 20/20 letter subtends 5 minutes of arc total. The deviation from parallelism between two surfaces, for instance in optical engineering , is usually measured in arcminutes or arcseconds. In addition, arcseconds are sometimes used in rocking curve (ω-scan) x ray diffraction measurements of high-quality epitaxial thin films. Some measurement devices make use of arcminutes and arcseconds to measure angles when
450-510: A 10-foot fairing). Additionally, the rocket deployed five CubeSats as a part of NASA ELaNa III manifest . The satellite was placed into a Sun-synchronous orbit (SSO) 833 km (518 mi) above the Earth . The Suomi NPP spacecraft has been built and integrated by BATC (Ball Aerospace and Technologies Corporation) of Boulder, Colorado (NASA/GSFC contract award in May 2002). The platform design
540-687: A circle with a diameter of 1.047 inches (which is often rounded to just 1 inch) at 100 yards (2.66 cm at 91 m or 2.908 cm at 100 m), a traditional distance on American target ranges . The subtension is linear with the distance, for example, at 500 yards, 1 MOA subtends 5.235 inches, and at 1000 yards 1 MOA subtends 10.47 inches. Since many modern telescopic sights are adjustable in half ( 1 / 2 ), quarter ( 1 / 4 ) or eighth ( 1 / 8 ) MOA increments, also known as clicks , zeroing and adjustments are made by counting 2, 4 and 8 clicks per MOA respectively. For example, if
630-459: A degree) and specify locations within about 120 metres (390 feet). For navigational purposes positions are given in degrees and decimal minutes, for instance The Needles lighthouse is at 50º 39.734’N 001º 35.500’W. Related to cartography, property boundary surveying using the metes and bounds system and cadastral surveying relies on fractions of a degree to describe property lines' angles in reference to cardinal directions . A boundary "mete"
720-560: A degree/day in the Earth's annual rotation around the Sun, which is off by roughly 1%. The same ratios hold for seconds, due to the consistent factor of 60 on both sides. The arcsecond is also often used to describe small astronomical angles such as the angular diameters of planets (e.g. the angular diameter of Venus which varies between 10″ and 60″); the proper motion of stars; the separation of components of binary star systems ; and parallax ,
810-422: A fraction of a mrad) are collectively called a mrad reticle. If the markings are round they are called mil-dots . In the table below conversions from mrad to metric values are exact (e.g. 0.1 mrad equals exactly 10 mm at 100 metres), while conversions of minutes of arc to both metric and imperial values are approximate. In humans, 20/20 vision is the ability to resolve a spatial pattern separated by
900-484: A group measuring 0.7 inches followed by a group that is 1.3 inches, this is not statistically abnormal. The metric system counterpart of the MOA is the milliradian (mrad or 'mil'), being equal to 1 ⁄ 1000 of the target range, laid out on a circle that has the observer as centre and the target range as radius. The number of milliradians on a full such circle therefore always is equal to 2 × π × 1000, regardless
990-400: A gun consistently shooting groups under 1 MOA. This means that a single group of 3 to 5 shots at 100 yards, or the average of several groups, will measure less than 1 MOA between the two furthest shots in the group, i.e. all shots fall within 1 MOA. If larger samples are taken (i.e., more shots per group) then group size typically increases, however this will ultimately average out. If a rifle
SECTION 10
#17327732652111080-530: A joint NASA / NOAA / DoD project, NPP was to be a pathfinder mission for the larger National Polar-orbiting Operational Environmental Satellite System (NPOESS) until DoD participation in the larger project was dissolved. The project continued as a civilian weather forecasting replacement for the NOAA Polar Operational Environmental Satellites (POES) series, and ensured continuity of climate measurements begun by
1170-455: A line running from the starting point 85.69 feet in a direction 65° 39′ 18″ (or 65.655°) away from north toward the west. The arcminute is commonly found in the firearms industry and literature, particularly concerning the precision of rifles , though the industry refers to it as minute of angle (MOA). It is especially popular as a unit of measurement with shooters familiar with the imperial measurement system because 1 MOA subtends
1260-420: A minute, for example, written as 42° 25.32′ or 42° 25.322′. This notation has been carried over into marine GPS and aviation GPS receivers, which normally display latitude and longitude in the latter format by default. The average apparent diameter of the full Moon is about 31 arcminutes, or 0.52°. One arcminute is the approximate distance two contours can be separated by, and still be distinguished by,
1350-431: A modern second. Since antiquity, the arcminute and arcsecond have been used in astronomy : in the ecliptic coordinate system as latitude (β) and longitude (λ); in the horizon system as altitude (Alt) and azimuth (Az); and in the equatorial coordinate system as declination (δ). All are measured in degrees, arcminutes, and arcseconds. The principal exception is right ascension (RA) in equatorial coordinates, which
1440-587: A more intense storm). Infrared pictures depict ocean eddies or vortices and map currents such as the Gulf Stream which are valuable to the shipping industry. Fishermen and farmers are interested in knowing land and water temperatures to protect their crops against frost or increase their catch from the sea. Even El Niño phenomena can be spotted. Using color-digitized techniques, the gray shaded thermal images can be converted to color for easier identification of desired information. Each meteorological satellite
1530-725: A much better resolution than their geostationary counterparts due their closeness to the Earth. The United States has the NOAA series of polar orbiting meteorological satellites, presently NOAA-15, NOAA-18 and NOAA-19 ( POES ) and NOAA-20 and NOAA-21 ( JPSS ). Europe has the Metop -A, Metop -B and Metop -C satellites operated by EUMETSAT . Russia has the Meteor and RESURS series of satellites. China has FY -3A, 3B and 3C. India has polar orbiting satellites as well. The United States Department of Defense 's Meteorological Satellite ( DMSP ) can "see"
1620-734: A nominally normal orientation to the Sun. In addition, a single-wing solar array is mounted on the anti-solar side of the spacecraft; its function is to preclude thermal input into the sensitive cryo radiators of the Visible Infrared Imaging Radiometer Suite (VIIRS) and Cross-track Infrared Sounder (CrIS) instruments. A regulated 28 ±6 VDC power bus distributes energy to all spacecraft subsystems and instruments. A nickel–hydrogen battery (NiH) system provides power for eclipse phase operations. The spacecraft has an on-orbit design lifetime of five years (available consumables for seven years). The spacecraft dry mass
1710-447: A number of changes over its predecessors in support of its mission to gather data for weather forecasting and climate monitoring. The MTG satellites are three-axis stabilised rather than spin stabilised, giving greater flexibility in satellite and instrument design. The MTG system features separate Imager and Sounder satellite models that share the same satellite bus, with a baseline of three satellites - two Imagers and one Sounder - forming
1800-860: A pathfinder for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) program, which was to have replaced NOAA's Polar Operational Environmental Satellites (POES) and the U.S. Air Force 's Defense Meteorological Satellite Program (DMSP). Suomi NPP was launched in 2011 after the cancellation of NPOESS to serve as a stop-gap between the POES satellites and the Joint Polar Satellite System (JPSS) which will replace them. Its instruments provide climate measurements that continue prior observations by NASA 's Earth Observing System (EOS). The satellite
1890-528: A period at the end of a sentence in the Apollo mission manuals left on the Moon as seen from Earth. One nanoarcsecond is about the size of a penny on Neptune 's moon Triton as observed from Earth. Also notable examples of size in arcseconds are: The concepts of degrees, minutes, and seconds—as they relate to the measure of both angles and time—derive from Babylonian astronomy and time-keeping. Influenced by
SECTION 20
#17327732652111980-535: A person with 20/20 vision . One arcsecond is the approximate angle subtended by a U.S. dime coin (18 mm) at a distance of 4 kilometres (about 2.5 mi). An arcsecond is also the angle subtended by One milliarcsecond is about the size of a half dollar, seen from a distance equal to that between the Washington Monument and the Eiffel Tower . One microarcsecond is about the size of
2070-468: A precision-oriented firearm's performance will be measured in MOA. This simply means that under ideal conditions (i.e. no wind, high-grade ammo, clean barrel, and a stable mounting platform such as a vise or a benchrest used to eliminate shooter error), the gun is capable of producing a group of shots whose center points (center-to-center) fit into a circle, the average diameter of circles in several groups can be subtended by that amount of arc. For example,
2160-723: A scatterometer and a radio-occultation instrument. The satellite service module is based on the SPOT-5 bus, while the payload suite is a combination of new and heritage instruments from both Europe and the US under the Initial Joint Polar System agreement between EUMETSAT and NOAA. A second generation of Metop satellites ( MetOp-SG ) is in advanced development with launch of the first satellite foreseen in 2025. As with MTG, Metop-SG will launch on Ariane-6 and comprise two satellite models to be operated in pairs in replacement of
2250-524: A second imager satellite will operate from 9.5-deg East to perform a Rapid Scanning mission over Europe. MTG continues Meteosat support to the ARGOS and Search and Rescue missions. MTG-I1 launched in one of the last Ariane-5 launches, with the subsequent satellites planned to launch in Ariane-6 when it enters service. In 2006, the first European low-Earth orbit operational meteorological satellite, Metop -A
2340-506: A trained analyst to determine cloud heights and types, to calculate land and surface water temperatures, and to locate ocean surface features. Infrared satellite imagery can be used effectively for tropical cyclones with a visible eye pattern, using the Dvorak technique , where the difference between the temperature of the warm eye and the surrounding cold cloud tops can be used to determine its intensity (colder cloud tops generally indicate
2430-462: A valuable asset in such situations. Nighttime photos also show the burn-off in gas and oil fields. Atmospheric temperature and moisture profiles have been taken by weather satellites since 1969. Not all weather satellites are direct imagers . Some satellites are sounders that take measurements of a single pixel at a time. They have no horizontal spatial resolution but often are capable or resolving vertical atmospheric layers . Soundings along
2520-739: Is a variation of BCP 2000 (Ball Commercial Platform) bus of BATC of ICESat and CloudSat heritage. The spacecraft consists of an aluminum honeycomb structure. The ADCS (Attitude Determination and Control Subsystem) provides three-axis stabilization using four reaction wheels for fine attitude control, three torquer bars for momentum unloading, thrusters for coarse attitude control (such as during large-angle slews for orbital maintenance), two star trackers for fine attitude determination, three gyroscopes for attitude and attitude rate determination between star tracker updates, two Earth sensors for safe-mode attitude control, and coarse Sun sensors for initial attitude acquisition, all monitored and controlled by
2610-414: Is about 1400 kg. NPP is designed to support controlled reentry at the end of its mission life (via propulsive maneuvers to lower the orbit perigee to approximately 50 km and target any surviving debris for open ocean entry). NPP is expected to have sufficient debris that survives reentry so as to require controlled reentry to place the debris in a pre-determined location in the ocean. The Suomi NPP
2700-434: Is also abbreviated as arcmin or amin . Similarly, double prime ″ (U+2033) designates the arcsecond, though a double quote " (U+0022) is commonly used where only ASCII characters are permitted. One arcsecond is thus written as 1″. It is also abbreviated as arcsec or asec . In celestial navigation , seconds of arc are rarely used in calculations, the preference usually being for degrees, minutes, and decimals of
2790-518: Is classified in accordance with ITU Radio Regulations (article 1) as follows: Fixed service (article 1.20) The allocation of radio frequencies is provided according to Article 5 of the ITU Radio Regulations (edition 2012). In order to improve harmonisation in spectrum utilisation, the majority of service-allocations stipulated in this document were incorporated in national Tables of Frequency Allocations and Utilisations which
Suomi NPP - Misplaced Pages Continue
2880-486: Is described with a beginning reference point, the cardinal direction North or South followed by an angle less than 90 degrees and a second cardinal direction, and a linear distance. The boundary runs the specified linear distance from the beginning point, the direction of the distance being determined by rotating the first cardinal direction the specified angle toward the second cardinal direction. For example, North 65° 39′ 18″ West 85.69 feet would describe
2970-446: Is designed to use one of two different classes of orbit: geostationary and polar orbiting . Geostationary weather satellites orbit the Earth above the equator at altitudes of 35,880 km (22,300 miles). Because of this orbit , they remain stationary with respect to the rotating Earth and thus can record or transmit images of the entire hemisphere below continuously with their visible-light and infrared sensors. The news media use
3060-423: Is measured in time units of hours, minutes, and seconds. Contrary to what one might assume, minutes and seconds of arc do not directly relate to minutes and seconds of time, in either the rotational frame of the Earth around its own axis (day), or the Earth's rotational frame around the Sun (year). The Earth's rotational rate around its own axis is 15 minutes of arc per minute of time (360 degrees / 24 hours in day);
3150-504: Is named after Verner E. Suomi , a Finnish-American meteorologist at the University of Wisconsin–Madison . The name was announced on 24 January 2012, three months after the satellite's launch. Suomi NPP was intended to bridge the gap between the old Earth Observing System (EOS) and the new JPSS system by flying new instruments, on a new satellite bus, using a new ground data network. Originally planned for launch five years earlier as
3240-503: Is roughly 30 metres (98 feet). The exact distance varies along meridian arcs or any other great circle arcs because the figure of the Earth is slightly oblate (bulges a third of a percent at the equator). Positions are traditionally given using degrees, minutes, and seconds of arcs for latitude , the arc north or south of the equator, and for longitude , the arc east or west of the Prime Meridian . Any position on or above
3330-626: Is that some MOA scopes, including some higher-end models, are calibrated such that an adjustment of 1 MOA on the scope knobs corresponds to exactly 1 inch of impact adjustment on a target at 100 yards, rather than the mathematically correct 1.047 inches. This is commonly known as the Shooter's MOA (SMOA) or Inches Per Hundred Yards (IPHY). While the difference between one true MOA and one SMOA is less than half of an inch even at 1000 yards, this error compounds significantly on longer range shots that may require adjustment upwards of 20–30 MOA to compensate for
3420-596: Is the first in a new generation of satellites intended to replace the Earth Observing System (EOS) satellites, which were launched from 1997 to 2009. The satellite orbits the Earth about 14 times each day. Its five imaging systems include: The Visible Infrared Imaging Radiometer Suite (VIIRS) is the largest instrument aboard of Suomi-NPP (National Polar-Orbiting Operational Environmental Satellite System ( NPOESS ) Preparatory Project). It collects radiometric imagery in visible and infrared wavelengths of
3510-411: Is what has given humanity the capability to make accurate and preemptive space weather forecasts since the late 2010s. In Europe, the first Meteosat geostationary operational meteorological satellite, Meteosat-1, was launched in 1977 on a Delta launch vehicle. The satellite was a spin-stabilised cylindrical design, 2.1 m in diameter and 3.2 m tall, rotating at approx. 100 rpm and carrying
3600-423: Is with-in the responsibility of the appropriate national administration. The allocation might be primary, secondary, exclusive, and shared. Minute and second of arc A minute of arc , arcminute ( arcmin ), arc minute , or minute arc , denoted by the symbol ′ , is a unit of angular measurement equal to 1 / 60 of one degree . Since one degree is 1 / 360 of
3690-550: The COSPAS-SARSAT Search and Rescue (SAR) and ARGOS Data Collection Platform (DCP) missions. SEVIRI provided an increased number of spectral channels over MVIRI and imaged the full-Earth disc at double the rate. Meteosat-9 was launched to complement Meteosat-8 in 2005, with the second pair consisting of Meteosat-10 and Meteosat-11 launched in 2012 and 2015, respectively. The Meteosat Third Generation (MTG) programme launched its first satellite in 2022, and featured
Suomi NPP - Misplaced Pages Continue
3780-475: The Earth Observing System (EOS) of NASA. The spacecraft was launched on 28 October 2011 from Space Launch Complex-2W (SLC-2W) at Vandenberg Space Force Base in California by a United Launch Alliance Delta II in the 7920-10 configuration (Extra Extended Long Tank with RS-27A engine first stage, 9 GEM-40 solid rocket motors, type 2 second stage with Aerojet AJ10 -118K engine, no third stage and
3870-592: The European Commission 's Copernicus programme and fulfils the Sentinel-4 mission to monitor air quality, trace gases and aerosols over Europe hourly at high spatial resolution. Two MTG satellites - one Imager and one Sounder - will operate in close proximity from the 0-deg geostationary location over western Africa to observe the eastern Atlantic Ocean, Europe, Africa and the Middle East, while
3960-995: The Meteosat Visible and Infrared Imager (MVIRI) instrument. Successive Meteosat first generation satellites were launched, on European Ariane-4 launchers from Kourou in French Guyana, up to and including Meteosat-7 which acquired data from 1997 until 2017, operated initially by the European Space Agency and later by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). Japan has launched nine Himawari satellites beginning in 1977. Starting in 1988 China has launched twenty-one Fengyun satellites. The Meteosat Second Generation (MSG) satellites - also spin stabilised although physically larger and twice
4050-485: The Sumerians , the ancient Babylonians divided the Sun's perceived motion across the sky over the course of one full day into 360 degrees. Each degree was subdivided into 60 minutes and each minute into 60 seconds. Thus, one Babylonian degree was equal to four minutes in modern terminology, one Babylonian minute to four modern seconds, and one Babylonian second to 1 / 15 (approximately 0.067) of
4140-507: The Ultraviolet index . OMPS has two sensors, both new designs, composed of three advanced hyperspectral-imaging spectrometers. The Clouds and the Earth's Radiant Energy System (CERES) will be used to study the Earth's radiation budget . Monitoring the amount of energy emitted and reflected by the planet, it measures both solar energy reflected by the Earth and heat emitted by our planet. This solar and thermal energy are key parts of
4230-400: The milliarcsecond (mas) and microarcsecond (μas), for instance, are commonly used in astronomy. For a three-dimensional area such as on a sphere, square arcminutes or seconds may be used. The prime symbol ′ ( U+ 2032 ) designates the arcminute, though a single quote ' (U+0027) is commonly used where only ASCII characters are permitted. One arcminute is thus written as 1′. It
4320-479: The ozone layer in our upper atmosphere tracking the status of global ozone distributions, including the ozone hole . It also monitors ozone levels in the troposphere . OMPS extends out 40-year long record ozone layer measurements while also providing improved vertical resolution compared to previous operational instruments. Closer to the ground, OMPS's measurements of harmful ozone improve air quality monitoring and when combined with cloud predictions; help to create
4410-532: The solar radiation balance of the tropics. Other dust storms in Asia and mainland China are common and easy to spot and monitor, with recent examples of dust moving across the Pacific Ocean and reaching North America. In remote areas of the world with few local observers, fires could rage out of control for days or even weeks and consume huge areas before authorities are alerted. Weather satellites can be
4500-444: The watersheds of the western United States. This information is gleaned from existing satellites of all agencies of the U.S. government (in addition to local, on-the-ground measurements). Ice floes, packs, and bergs can also be located and tracked from weather spacecraft. Even pollution whether it is nature-made or human-made can be pinpointed. The visual and infrared photos show effects of pollution from their respective areas over
4590-537: The 1962 Defense Satellite Applications Program (DSAP) and the 1964 Soviet Meteor series . TIROS paved the way for the Nimbus program , whose technology and findings are the heritage of most of the Earth-observing satellites NASA and NOAA have launched since then. Beginning with the Nimbus 3 satellite in 1969, temperature information through the tropospheric column began to be retrieved by satellites from
SECTION 50
#17327732652114680-605: The Cross-track Infrared Sounder (CrIS) to make detailed vertical profiles of atmospheric pressure, heat, and moisture. ATMS, a cross-track scanner with 22 channels, provides sounding observations needed to retrieve profiles of atmospheric temperature and moisture for civilian operational weather forecasting as well as continuity of these measurements for climate monitoring purposes. CrIS will operate at infrared wavelengths, while ATMS will operate at much shorter, microwave, wavelengths. The VIIRS sensor on board
4770-446: The Earth at a typical altitude of 850 km (530 miles) in a north to south (or vice versa) path, passing over the poles in their continuous flight. Polar orbiting weather satellites are in sun-synchronous orbits , which means they are able to observe any place on Earth and will view every location twice each day with the same general lighting conditions due to the near-constant local solar time . Polar orbiting weather satellites offer
4860-451: The Earth's reference ellipsoid can be precisely given with this method. However, when it is inconvenient to use base -60 for minutes and seconds, positions are frequently expressed as decimal fractional degrees to an equal amount of precision. Degrees given to three decimal places ( 1 / 1000 of a degree) have about 1 / 4 the precision of degrees-minutes-seconds ( 1 / 3600 of
4950-606: The Earth's atmosphere but are diffraction limited . For example, the Hubble Space Telescope can reach an angular size of stars down to about 0.1″. Minutes (′) and seconds (″) of arc are also used in cartography and navigation . At sea level one minute of arc along the equator equals exactly one geographical mile (not to be confused with international mile or statute mile) along the Earth's equator or approximately one nautical mile (1,852 metres ; 1.151 miles ). A second of arc, one sixtieth of this amount,
5040-490: The Earth's radiation budget. CERES instrument continues a multi-year record of the amount of energy entering and exiting from the top of the atmosphere of Earth . It will provide scientists with needed long-term, stable data sets to make accurate projections of global climate change. The Cross-track Infrared Sounder (CrIS) has 1305 spectral channels and will produce high-resolution, three-dimensional temperature, pressure, and moisture profiles. It measures continuous channels in
5130-475: The Earth's rotational rate around the Sun (not entirely constant) is roughly 24 minutes of time per minute of arc (from 24 hours in day), which tracks the annual progression of the Zodiac. Both of these factor in what astronomical objects you can see from surface telescopes (time of year) and when you can best see them (time of day), but neither are in unit correspondence. For simplicity, the explanations given assume
5220-835: The Indian Ocean. The Japanese have the MTSAT -2 located over the mid Pacific at 145°E and the Himawari 8 at 140°E. The Europeans have four in operation, Meteosat -8 (3.5°W) and Meteosat-9 (0°) over the Atlantic Ocean and have Meteosat-6 (63°E) and Meteosat-7 (57.5°E) over the Indian Ocean. China currently has four Fengyun (风云) geostationary satellites (FY-2E at 86.5°E, FY-2F at 123.5°E, FY-2G at 105°E and FY-4A at 104.5 °E) operated. India also operates geostationary satellites called INSAT which carry instruments for meteorological purposes. Polar orbiting weather satellites circle
5310-529: The U.S., Europe, India, China, Russia, and Japan provide nearly continuous observations for a global weather watch. As early as 1946, the idea of cameras in orbit to observe the weather was being developed. This was due to sparse data observation coverage and the expense of using cloud cameras on rockets. By 1958, the early prototypes for TIROS and Vanguard (developed by the Army Signal Corps ) were created. The first weather satellite, Vanguard 2 ,
5400-451: The angle, measured in arcseconds, of the object's apparent movement caused by parallax. The European Space Agency 's astrometric satellite Gaia , launched in 2013, can approximate star positions to 7 microarcseconds (μas). Apart from the Sun, the star with the largest angular diameter from Earth is R Doradus , a red giant with a diameter of 0.05″. Because of the effects of atmospheric blurring , ground-based telescopes will smear
5490-591: The best of all weather vehicles with its ability to detect objects almost as 'small' as a huge oil tanker . In addition, of all the weather satellites in orbit, only DMSP can "see" at night in the visual. Some of the most spectacular photos have been recorded by the night visual sensor; city lights, volcanoes , fires, lightning, meteors , oil field burn-offs, as well as the Aurora Borealis and Aurora Australis have been captured by this 720 kilometres (450 mi) high space vehicle's low moonlight sensor. At
SECTION 60
#17327732652115580-628: The bullet drop. If a shot requires an adjustment of 20 MOA or more, the difference between true MOA and SMOA will add up to 1 inch or more. In competitive target shooting, this might mean the difference between a hit and a miss. The physical group size equivalent to m minutes of arc can be calculated as follows: group size = tan( m / 60 ) × distance. In the example previously given, for 1 minute of arc, and substituting 3,600 inches for 100 yards, 3,600 tan( 1 / 60 ) ≈ 1.047 inches. In metric units 1 MOA at 100 metres ≈ 2.908 centimetres. Sometimes,
5670-578: The eastern Atlantic and most of the Pacific Ocean, which led to significant improvements to weather forecasts . The ESSA and NOAA polar orbiting satellites followed suit from the late 1960s onward. Geostationary satellites followed, beginning with the ATS and SMS series in the late 1960s and early 1970s, then continuing with the GOES series from the 1970s onward. Polar orbiting satellites such as QuikScat and TRMM began to relay wind information near
5760-553: The entire Earth asynchronously), or geostationary (hovering over the same spot on the equator ). While primarily used to detect the development and movement of storm systems and other cloud patterns, meteorological satellites can also detect other phenomena such as city lights, fires, effects of pollution, auroras , sand and dust storms , snow cover, ice mapping, boundaries of ocean currents , and energy flows. Other types of environmental information are collected using weather satellites. Weather satellite images helped in monitoring
5850-705: The entire earth. Aircraft and rocket pollution, as well as condensation trails , can also be spotted. The ocean current and low level wind information gleaned from the space photos can help predict oceanic oil spill coverage and movement. Almost every summer, sand and dust from the Sahara Desert in Africa drifts across the equatorial regions of the Atlantic Ocean. GOES-EAST photos enable meteorologists to observe, track and forecast this sand cloud. In addition to reducing visibilities and causing respiratory problems, sand clouds suppress hurricane formation by modifying
5940-505: The geostationary photos in their daily weather presentation as single images or made into movie loops. These are also available on the city forecast pages of www.noaa.gov (example Dallas, TX). Several geostationary meteorological spacecraft are in operation. The United States' GOES series has three in operation: GOES-15 , GOES-16 and GOES-17 . GOES-16 and-17 remain stationary over the Atlantic and Pacific Oceans, respectively. GOES-15
6030-405: The image of a star to an angular diameter of about 0.5″; in poor conditions this increases to 1.5″ or even more. The dwarf planet Pluto has proven difficult to resolve because its angular diameter is about 0.1″. Techniques exist for improving seeing on the ground. Adaptive optics , for example, can produce images around 0.05″ on a 10 m class telescope. Space telescopes are not affected by
6120-413: The infrared region and has the ability to measure temperature profiles with improved accuracy over its predecessors. These profiles will be used to enhance weather forecasting models and will facilitate both short- and long-term weather forecasting. Over longer timescales, they will help improve understanding of climate phenomena. The Advanced Technology Microwave Sounder (ATMS), works in conjunction with
6210-510: The land, atmosphere, ice, and ocean. It will survey broad swaths of the land, oceans, and air, enabling scientists to monitor everything from phytoplankton and other organisms in the sea, vegetation and forest cover, and the amount of sea ice at the poles. Data from VIIRS, collected from 22 channels across the electromagnetic spectrum , will also be used to observe active fires, ocean color, sea surface temperature , and other surface features. The Ozone Mapping and Profiler Suite (OMPS) measures
6300-666: The mass of the first generation - were developed by ESA with European industry and in cooperation with EUMETSAT who then operate the satellites from their headquarters in Darmstadt, Germany with this same approach followed for all subsequent European meteorological satellites. Meteosat-8 , the first MSG satellite, was launched in 2002 on an Ariane-5 launcher, carrying the Spinning Enhanced Visible and Infrared Imager (SEVIRI) and Geostationary Earth Radiation Budget (GERB) instruments, along with payloads to support
6390-510: The most dramatic photos showed the 600 Kuwaiti oil fires that the fleeing Army of Iraq started on February 23, 1991. The night photos showed huge flashes, far outstripping the glow of large populated areas. The fires consumed huge quantities of oil; the last was doused on November 6, 1991. Snowfield monitoring, especially in the Sierra Nevada , can be helpful to the hydrologist keeping track of available snowpack for runoff vital to
6480-484: The ocean's surface starting in the late 1970s, with microwave imagery which resembled radar displays, which significantly improved the diagnoses of tropical cyclone strength, intensification, and location during the 2000s and 2010s. The DSCOVR satellite, owned by NOAA, was launched in 2015 and became the first deep space satellite that can observe and predict space weather. It can detect potentially dangerous weather such as solar wind and geomagnetic storms . This
6570-547: The operational configuration. The imager satellites carry the Flexible Combined Imager (FCI), succeeding MVIRI and SEVIRI to give even greater resolution and spectral coverage, scanning the full Earth disc every ten minutes, as well as a new Lightning Imager (LI) payload. The sounder satellites carry the Infrared Sounder (IRS) and Ultra-violet Visible Near-infrared (UVN) instruments. UVN is part of
6660-403: The point of impact is 3 inches high and 1.5 inches left of the point of aim at 100 yards (which for instance could be measured by using a spotting scope with a calibrated reticle, or a target delineated for such purposes), the scope needs to be adjusted 3 MOA down, and 1.5 MOA right. Such adjustments are trivial when the scope's adjustment dials have a MOA scale printed on them, and even figuring
6750-470: The right number of clicks is relatively easy on scopes that click in fractions of MOA. This makes zeroing and adjustments much easier: Another common system of measurement in firearm scopes is the milliradian (mrad). Zeroing an mrad based scope is easy for users familiar with base ten systems. The most common adjustment value in mrad based scopes is 1 / 10 mrad (which approximates 1 ⁄ 3 MOA). One thing to be aware of
6840-424: The same time, energy use and city growth can be monitored since both major and even minor cities, as well as highway lights, are conspicuous. This informs astronomers of light pollution . The New York City Blackout of 1977 was captured by one of the night orbiter DMSP space vehicles. In addition to monitoring city lights, these photos are a life saving asset in the detection and monitoring of fires. Not only do
6930-606: The satellite ground track can still be gridded later to form maps . According to the International Telecommunication Union (ITU), a meteorological-satellite service (also: meteorological-satellite radiocommunication service ) is – according to Article 1.52 of the ITU Radio Regulations (RR) – defined as « An earth exploration-satellite service for meteorological purposes.» This radiocommunication service
7020-429: The satellites see the fires visually day and night, but the thermal and infrared scanners on board these weather satellites detect potential fire sources below the surface of the Earth where smoldering occurs. Once the fire is detected, the same weather satellites provide vital information about wind that could fan or spread the fires. These same cloud photos from space tell the firefighter when it will rain. Some of
7110-785: The single first generation satellites to continue the EPS mission. Observation is typically made via different 'channels' of the electromagnetic spectrum , in particular, the visible and infrared portions. Some of these channels include: Visible-light images from weather satellites during local daylight hours are easy to interpret even by the average person, clouds, cloud systems such as fronts and tropical storms, lakes, forests, mountains, snow ice, fires, and pollution such as smoke, smog, dust and haze are readily apparent. Even wind can be determined by cloud patterns, alignments and movement from successive photos. The thermal or infrared images recorded by sensors called scanning radiometers enable
7200-411: The small change of position of a star or Solar System body as the Earth revolves about the Sun. These small angles may also be written in milliarcseconds (mas), or thousandths of an arcsecond. The unit of distance called the parsec , abbreviated from the par allax angle of one arc sec ond, was developed for such parallax measurements. The distance from the Sun to a celestial object is the reciprocal of
7290-511: The spacecraft acquired its first measurements of Earth on 21 November 2011. NASA also released a high resolution blue marble image of the Earth showing most of North America , which was created by NASA oceanographer Norman Kuring using data obtained on 4 January 2012 by the Visible Infrared Imager Radiometer Suite (VIIRS), one of five imaging systems aboard the satellite. That date was chosen because it
7380-471: The spacecraft controls a computer. ADCS provides real-time attitude knowledge of 10 arcsec (1 sigma) at the spacecraft navigation reference base, real-time spacecraft position knowledge of 25 m (1 sigma), and attitude control of 36 arcsec (1 sigma). The EPS (Electrical Power Subsystem) uses gallium arsenide (GaAs) solar cells to generate an average power of about 2 kW (EOL). The solar array rotates once per orbit to maintain
7470-673: The symbol ″ , is 1 / 60 of an arcminute, 1 / 3600 of a degree, 1 / 1 296 000 of a turn, and π / 648 000 (about 1 / 206 264 .8 ) of a radian. These units originated in Babylonian astronomy as sexagesimal (base 60) subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy , optometry , ophthalmology , optics , navigation , land surveying , and marksmanship . To express even smaller angles, standard SI prefixes can be employed;
7560-419: The target range. Therefore, 1 MOA ≈ 0.2909 mrad. This means that an object which spans 1 mrad on the reticle is at a range that is in metres equal to the object's linear size in millimetres (e.g. an object of 100 mm subtending 1 mrad is 100 metres away). So there is no conversion factor required, contrary to the MOA system. A reticle with markings (hashes or dots) spaced with a one mrad apart (or
7650-399: The volcanic ash cloud from Mount St. Helens and activity from other volcanoes such as Mount Etna . Smoke from fires in the western United States such as Colorado and Utah have also been monitored. El Niño and its effects on weather are monitored daily from satellite images. The Antarctic ozone hole is mapped from weather satellite data. Collectively, weather satellites flown by
7740-403: Was a fairly sunny day in most of North America. As of 22 November 2020, beyond the initial 5-year mission, the spacecraft continues to operate. Weather satellite A weather satellite or meteorological satellite is a type of Earth observation satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be polar orbiting (covering
7830-595: Was launched into a Sun-synchronous orbit at 817 km altitude by a Soyuz launcher from Baikonur, Kazakhstan. This operational satellite - which forms the space segment of the EUMETSAT Polar System (EPS) - built on the heritage from ESA's ERS and Envisat experimental missions, and was followed at six-year intervals by Metop-B and Metop-C - the latter launched from French Guyana in a "Europeanised" Soyuz . Each carry thirteen different passive and active instruments ranging in design from imagers and sounders to
7920-550: Was launched on February 17, 1959. It was designed to measure cloud cover and resistance, but a poor axis of rotation and its elliptical orbit kept it from collecting a notable amount of useful data. The Explorer 6 and Explorer 7 satellites also contained weather-related experiments. The first weather satellite to be considered a success was TIROS-1 , launched by NASA on April 1, 1960. TIROS operated for 78 days and proved to be much more successful than Vanguard 2. Other early weather satellite programs include
8010-534: Was retired in early July 2019. The satellite GOES 13 that was previously owned by the National Oceanic and Atmospheric Association (NOAA) was transferred to the U.S. Space Force in 2019 and renamed the EWS-G1; becoming the first geostationary weather satellite to be owned and operated by the U.S. Department of Defense. Russia 's new-generation weather satellite Elektro-L No.1 operates at 76°E over
8100-446: Was truly a 1 MOA rifle, it would be just as likely that two consecutive shots land exactly on top of each other as that they land 1 MOA apart. For 5-shot groups, based on 95% confidence , a rifle that normally shoots 1 MOA can be expected to shoot groups between 0.58 MOA and 1.47 MOA, although the majority of these groups will be under 1 MOA. What this means in practice is if a rifle that shoots 1-inch groups on average at 100 yards shoots
#210789