1 d
Coordinates earth science definition?
Follow
11
Coordinates earth science definition?
See latitude and longitude. To measure points on the Earth’s surface, geodesists assign coordinates (similar to a unique address. See latitude and longitude. The coordinate reference system is made up of several key components: Coordinate system:The X, Y grid upon which your data is overlayed and how you define where a point is located in space. A geodetic datum or reference frame is an abstract coordinate system with a reference surface (such as sea level) that serves to provide known locations to begin surveys and create maps NGS defines the official geodetic datums for all federal mapping activities in the U and its territories (see Table 1) as part of the National Spatial Reference System (NSRS). This method of calculation gives us geocentric lines of latitude. For instance, in geometry, we use x (horizontal) and y (vertical) coordinates to define points on a two-dimensional plane. Donald Trump said "mission accomplished!" on Twitter. Many coordinate systems are being used in geodesy, some concentric with the earth (geocentric systems), some not. Latitude is the measurement of distance north or south of the Equator. coordinate: [adjective] equal in rank, quality, or significance. The structure of the earth is divided into four major components: the crust, the mantle, the outer core, and the inner core. Longitude and Latitude are the two angles that define the precision location of a point on earth or the GPS coordinates. Cycles also play key roles in Earth's short-term weather and long-term climate. 51 Reference Surface for Geodetic Surveying Computations2 introduced the concept of the Earth ellipsoid. Each point on the Earth is uniquely defined by its cartesian coordinates (x, y, z). Longitude lines are Choose matching definition The altitude 90 degrees. [1] zenith, point on the celestial sphere directly above an observer on the Earth. The length of continuous day or night increases northward from one day on the Arctic. FIGURE 2. Longitude is the angular distance of a place east or west of the meridian at Greenwich, England, or west of the standard meridian of a celestial object. Latitude and longitude are like the Earth's address system, helping us pinpoint any location on the planet's surface. To measure points on the Earth’s surface, geodesists assign coordinates (similar to a unique address. "Above" means in the vertical direction opposite to the gravity direction at that location (). Since the rotation will be about the x-axis, the appropriate rotation matrix from equation (214) will be. The pair of numbers are called an ordered pair and make a point using an x and y axis. (At any latitude other than the equator, however, the north-south motion would have a component perpendicular to the rotation axis and a force specified by the inward or outward cases mentioned below). Navigation is the art and science of determining the position of a ship, plane or other vehicle, and guiding it to a specific destination. Solar declination is the angle between the Sun's rays and the plane of the Earth's Equator, and its value depends on where Earth is in its orbit around the Sun. Latitude, along with longitude, is an imaginary coordinate system used to communicate the location of a place on Earth. From the North Pole, all directions are south. The equator of the idealized earth is a great circle and any meridian and its opposite meridian form a great circle. Geocentric Coordinate. In fact, only 2 coordinates would suffice because each point is on the surface of a sphere: x 2 + … Offset corner latitude and longitude are just one example of the many coordinate systems used in Earth science. Foucault followed up in 1852 with a gyroscope experimentto further demonstrate the Earth's rotation. A circle of latitude is an imaginary ring linking all points sharing a parallel. In astronomy, declination (abbreviated dec; symbol δ) is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. Various different ellipsoids have been used as approximations It is a spheroid (an ellipsoid of revolution) whose minor axis (shorter diameter), which connects the geographical North Pole and South Pole, is. So, depending on the coordinate system, the values which describe a location will vary due to the origin's location and the unit of measure. The geoid describes it mathematically. The Sun reaches the observer's zenith when it is 90° above the. Tropics. Learn about Earth Day evolution at HowStuffWorks. The terms datum, projection and coordinate system are often misinterpreted and misunderstood. Plants are the backbone of life on Earth. Absolute coordinates are a type of data used in Geographic Information System (GIS) technology. Jun 16, 2024 · latitude and longitude, in cartography, a coordinate system used to determine and describe the position of any place on Earth ’s surface. When used as a celestial coordinate, the azimuth is the horizontal direction of a star or other astronomical object in the sky. These coordinates represent a unique and specific location on the earth's surface. Elevations are usually measured in meters or feet. declination, in astronomy, the angular distance of a body north or south of the celestial equator. The coordinate system used to define locations on the three-dimensional earth is the geographic coordinate system (GCS), based on a sphere or spheroid. The term also has meaning in any differentiable manifold with a connection. Maps are often marked with parallels and meridians, creating a grid. North and South poles are the maximum latitude points with. The latitude of a certain point on the surface of the Earth is the angle between two lines: a line from that location to the center of the Earth and a line from the center of the Earth to the Equator. Coordinates are linear and/or angular quantities that designate the position of a point in relation to a given reference frame. In a two-dimensional plane, x and y are commonly used to designate coordinates of a point. Coordinate definition: of the same order or degree; equal in rank or importance. Although any spherical body can be divided into an infinite number of hemispheres, geographers often divide Earth’s surface into four hemispheres that are separated by two great circle routes—that is, lines that represent the shortest distances that can be drawn between two points on the surface of a sphere—one coinciding with 0. The first number, known as the X value, indicates how. Elevations are usually measured in meters or feet. Coordinate systems are frameworks that are used to define unique positions. RA can be expressed in degrees, but it is more common to specify it in hours, minutes, and seconds of time: the sky appears to turn 360° in 24 hours, or 15° in one hour. Elevations are usually measured in meters or feet. On June 21, the summer solstice for the Northern Hemisphere, the northern end of the axis of rotation is pointing most directly toward. 1) Imagine standing at the center of the Earth and oriented parallel to the Earth’s axis. With it, we define the Geocentric Solar Ecliptic (GSE) coordinate system (blue). Are you looking to find the precise GPS coordinates for a particular location? Whether you need these coordinates for navigation purposes, geocaching, or simply out of curiosity, w. Cartesian coordinates are also essential tools for most applied disciplines that deal with geometry, including astronomy, physics, engineering and many more. Earth Coordinates Locate a point in Earth As you know, the Earth is a sphere, or at least it's very similar to a sphere. A coordinate system is a reference system used to represent the locations of geographic features, imagery, and observations, such as Global Positioning System (GPS) locations, within a common geographic framework. In a two-dimensional plane, x and y are commonly used to designate coordinates of a point. They're often denoted in terms of latitude and longitude or a similar coordinate system and typically use a globally or nationally recognized datum, a. Geodesy is the science of accurately measuring and understanding three fundamental properites of the Earth. The satellite coordinates as given in the broadcast ephemeris refers to the World Geodetic System of 1984 (WGS 84) reference system. Navigation is the art and science of determining the position of a ship, plane or other vehicle, and guiding it to a specific destination. The broad aim of the Earth sciences is to understand the present features and past evolution of Earth and to use this knowledge, where appropriate, for the benefit of humankind Thus, the basic concerns of the Earth. Included are the geologic, hydrologic, and atmospheric sciences. A datum is simply a foundation and reference for spatial measurements. being of equal rank in a sentence. For example, on Earth, this situation occurs for a body at the equator moving north or south relative to the Earth's surface. The geographic coordinate system is designed specifically to define positions on the Earth's roughly-spherical surface. 3 bed house for sale in leamington spa Enter Search Criteria. The barycentric celestial reference system (BCRS) is a coordinate system used in astrometry to specify the location and motions of astronomical objects. Latitude and longitude are parameters or coordinates that help determine the location of any place on Earth. Planetary and Space Science, 40, 711-717 T Geophysical coordinate transformations. The global positioning system (GPS) is a network of satellites and receiving devices used to determine the location of something on Earth. Geography is an all-encompassing discipline that seeks an understanding of Earth and its human and natural complexities—not merely where objects are, but also how they have changed and come to be. Barycentric coordinates (,,) on an equilateral triangle and on a right triangle. Jul 1, 2022 · A Geographic Coordinate System is a reference framework used to define the location of features on the surface of the Earth. RA can be expressed in degrees, but it is more common to specify it in hours, minutes, and seconds of time: the sky appears to turn 360° in 24 hours, or 15° in one hour. The deviation of the compass from true north is an angle called "declination" (or "magnetic declination"). The equations for proper. These coordinates represent a unique and specific location on the earth's surface. Although these are only imaginary lines, they appear on maps and globes as if they actually existed. The deviation of the compass from true north is an angle called "declination" (or "magnetic declination"). the arc or portion of the earth's equator intersected between the meridian of a given place and the prime meridian and. Navigation requires a person to know the vehicle's relative location, or position compared to other known locations. Mar 11, 2019 · Longitude (noun, “LAWN-gih-tood”) This is how scientists, geographers and sailors measure the east-west position of a location. Since the rotation will be about the x-axis, the appropriate rotation matrix from equation (214) will be. Training and education programs designed to increase the field's capacity to conduct rigorous implementation research, coordinated by IS team in collaboration with other academic i. It can also be used as the reference surface for geodetic surveying computations, which is called the reference ellipsoid. Maps are often marked with parallels and meridians, creating a grid. Earth Day has changed greatly since it was first observed in the 1970s. nike wallpaper These two coordinates are th. Coordinate system s used include the horizon system ( altitude and azimuth ), galactic coordinate s, the ecliptic system (measured relative to the orbital plane of Earth), and the equatorial system (right ascension and. Most coordinate systems use two numbers, a coordinate, to identify the location of a point. Maps that show elevations are called topographic maps. Antarctic Circle, parallel, or line of latitude around Earth, at 66°30′ S. The degree of the angle is between -90° and 90°. Oct 19, 2023 · Latitude is the measurement of distance north or south of the Equator. The International Date Line is the imaginary line that marks 180 degrees of. Longitude is the distance east or west of the Prime Meridian and is expressed as a number between 0 and 180 degrees east or west. Earth orbits the sun at a distance of 150 million kilometres and the sun orbits the centre of the Milky Way. The other set—lines of longitude—runs in a north-south direction. Many organizations use geodesy to map the U shoreline, determine land boundaries, and improve transportation and navigation safety. Very early maps (which usually showed small local or regional areas) used a grid technique which relied on. With it, we define the Geocentric Solar Ecliptic (GSE) coordinate system (blue). Geodesy or geodetics is the science of measuring and representing the geometry, gravity, and spatial orientation of the Earth in temporally varying 3D. Datum:A modeled version of the shape. Earth’s axis of rotation orients latitude so that … A coordinate system is a reference system used to represent the locations of geographic features, imagery, and observations, such as Global Positioning System … Geodesy or geodetics [1] is the science of measuring and representing the geometry, gravity, and spatial orientation of the Earth in temporally varying 3D. Discover the roles and responsibilities of an Event Coordinator and gain insights on how to become successful in this exciting field The role of an Event Coordinator i. Latitude definition: the angular distance north or south from the equator of a point on the earth's surface, measured on the meridian of the point See examples of LATITUDE used in a sentence. A datum is simply a foundation and reference for spatial measurements. AI generated definition based on: Treatise on Geophysics (Second Edition), 2015 Oct 19, 2023 · Longitude is related to latitude, the measurement of distance north or south of the Equator. Cartesian coordinates are named for René Descartes, whose invention of them in the 17th century revolutionized. Planning a wedding can be an exciting and joyous experience, but it can also be overwhelming and time-consuming. chestertown ny 12817 But before diving into the world of wedding coor. The first rotation of our initial coordinate system will be through the angle [-(π/2 - δ)]. Horizontal and vertical units:The units used to define the grid along the x, y (and z) axis. The Earth’s Coordinate System (Latitude and Longitude) The first step in converting the information contained in the real–world onto a ‘piece of paper’ was to devise a system where everything could be uniquely located in the world. It is primarily dipolar (i, it has two poles, the geomagnetic North and South poles) on Earth's surface. A century ago, Serbian scientist Milutin Milankovitch hypothesized the long-term, collective effects of changes in Earth's position relative to the Sun are a strong driver of Earth's long-term climate, and are responsible for triggering the beginning and end of glaciation periods (Ice Ages). Coordinate Systems. 4 (a): An ECEF Cartesian coordinate system showing the (X, Y, Z) coordinate locations. Until the advent of satellites, all geodesic work was based on land surveys made by triangulation methods employing a geodesic coordinate system (one used to study the geometry of curved surfaces). Geographic coordinates function by using number values. He called together a group of scientists, enticing them with a. In astronomy, the barycenter (or barycentre; from Ancient Greek βαρύς (barús) 'heavy', and κέντρον (kéntron) 'center') [1] is the center of mass of two or more bodies that orbit one another and is the point about which the bodies orbit. Longitude is the distance east or west of the Prime Meridian and is expressed as a number between 0 and 180 degrees east or west. The point 180° opposite the zenith, directly underfoot, is the nadir. The pair of numbers are called an ordered pair and make a point using an x and y axis. It is about 150 million kilometers (about 93 million miles) from the sun. Universal Transverse Mercator (UTM) v e. Elevation is distance above sea level. Definition of the parametric latitude (β) on the ellipsoid. Latitude and longitude are used together to specify the coordinates of a precise location on the Earth. The celestial equator is 0° DEC, and the poles are +90° and -90°.
Post Opinion
Like
What Girls & Guys Said
Opinion
49Opinion
This sediment is called alluvium Alluvial fans are usually created as flowing water interacts with mountains, hills, or the steep walls of canyons. The global positioning system (GPS) is a network of satellites and receiving devices used to determine the location of something on Earth. Latitude lines are geographical coordinates that are used to specify the north and south sides of the Earth. A coordinate system is a method for identifying the location of a point on the earth. Geographic (unprojected) coordinates, on the other hand, are polar coordinates defined by a distance (the radius of the Earth) and two angles (between a given location and the equator and between this location and the prime meridian). by ItStillWorks provi. Each of these numbers indicates the distance between the point and some fixed reference point, called the origin. In today’s digital age, maps have become an integral part of our lives. The horizontal number line is the x-axis, and the vertical. Datum:A modeled version of the shape. RA can be expressed in degrees, but it is more common to specify it in hours, minutes, and seconds of time: the sky appears to turn 360° in 24 hours, or 15° in one hour. Geographic latitude, which is the kind used in mapping, is calculated using a slightly different process. fireplace mantel surround An alluvial fan is a triangle-shaped deposit of gravel, sand, and even smaller pieces of sediment, such as silt. imaginary line around the Earth, another planet, or star running east-west, 0 degrees latitude noun. Elevation is the height above sea level. Light Detection and Ranging (LiDAR) : [remote sensing] LiDAR uses laser pulse measurements to identify heights, depths, and other properties of features. It is used to describe the position of a point on the Earth's surface relative to its center. A 3-simplex, with barycentric subdivisions of 1-faces (edges) 2-faces (triangles) and 3-faces (body). Its latitude is 90 degrees north, and all lines of longitude meet there (as well as at the South Pole, on the opposite end of Earth). Geodetic Science. (A small circle is the intersection between the surface of a sphere and a plane that cut through the sphere but does not pass through the center of the sphere. The two coordinates constitute a useful means of locating the relative positions and motions of components of the Milky Way Galaxy. Oct 19, 2023 · Latitude is the measurement of distance north or south of the Equator. Commonly called a grid system, it is made up of two sets of lines that cross each other. 'the directions') [1] is the. Very early maps (which usually showed small local or regional areas) used a grid technique which relied on. Earth Coordinates Locate a point in Earth As you know, the Earth is a sphere, or at least it's very similar to a sphere. Geodesy or geodetics is the science of measuring and representing the geometry, gravity, and spatial orientation of the Earth in temporally varying 3D. instagram beach picture poses For example, you can use decimal degrees or degrees-minutes-seconds. Several concepts are key to understanding the impact of coordinate systems and geodetics on GIS data collection workflows Datums. Until the advent of satellites, all geodesic work was based on land surveys made by triangulation methods employing a geodesic coordinate system (one used to study the geometry of curved surfaces). Fully assembled by the Early Permian Epoch (some 299 million to about 273 million years ago), it began to break apart about 200 million years ago, eventually forming the modern continents and the Atlantic and Indian oceans. The latitude of a certain point on the surface of the Earth is the angle between two lines: a line from that location to the center of the Earth and a line from the center of the Earth to the Equator. It is a system of latitude and longitude coordinates that defines a three-dimensional position of a point on the Earth’s surface. Earth is a rotating sphere, so its coordinate system uses latitude and longitude to locate positions on the planet. Quiz yourself with questions and answers for Science Quiz Coordinates, so you can be ready for test day How long does it take for Earth to do one rotation? 5 of 18 Vertical. The equation of a circle is (x − a)2 + (y − b)2 = r2 where a and b are the coordinates of the center (a, b) and r is the radius. See latitude and longitude. It is the precise point of the intersection of Earth's axis and Earth's surface. It is possible to express a point on the Earth's surface in terms of these x, y, and z-coordinates in this Earth-Centered, Earth-Fixed, or ECEF system. The pair of numbers are called an ordered pair and make a point using an x and y axis. For many reasons, like the Earth's rotation and poles, an ellipsoid works much better than a. v e. Sometimes the way it transforms to frames considered as related is emphasized as. used high top conversion vans for sale by owner Its latitude is 90 degrees north, and all lines of longitude meet there (as well as at the South Pole, on the opposite end of Earth). Earth’s latitudes experience the solstices in different ways. Feb 24, 2012 · Latitude is the distance north or south of the Equator and is expressed as a number between 0 and 90 degrees north or south. Celestial latitude ( b ) is an object ' s arc distance from the ecliptic along its secondary to the ecliptic. Advertisement The very first Earth Day, in April 1970, wa. Three-dimensional coordinates are used to mark the position of stars, planets, constellations, and other heavenly bodies. They describe how (1) planets move in elliptical orbits with the Sun as a focus, (2) a planet covers the same area of space in the same amount of time no matter where it is in its orbit, and (3) a planet's orbital period is proportional to the size of its orbit. Planetary and Space Science, 40, 711-717 T Geophysical coordinate transformations. These lines are known as parallels. The atmospheric science channel contains information about the atmosphere. Several other factors would have to line up, of course, for surface water to be present. Closer to the Earth the relative importance of the Earth's field becomes stronger, so that a more precise alignment with the dipole axis is required. They can be shown on maps by contour lines, which connect points with the same elevation; by bands of color; or by numbers giving the exact elevations of particular points on the Earth's surface. These lines are known as parallels.
Arctic Circle, parallel, or line of latitude around Earth, at approximately 66°30′ N. Search Limits: The search result limit is 100 records; select a Country, Feature Class, and/or Feature Type to. The surface where they slip is called the fault or fault plane. Gray is a versatile and sophisticated color that can serve as the perfect backdrop for any space. These coordinates are based on an ellipsoid that approximates the shape of the Earth, and. It consists of a coordinate system, a … Coordinate reference systems are used to convert locations on the earth which is round, to a two dimensional (flat) map. The parametric latitude or reduced latitude, β, is defined by the radius drawn from the centre of the ellipsoid to that point Q on the surrounding sphere (of radius a) which is the projection parallel to the Earth's axis of a point P on the ellipsoid at latitude ϕ. It is a mathematical way of depicting three dimensions (3D) in a two dimensional (2D) format, using three values known as X, Y, and Z. replace ebt card online nj The point 180° opposite the zenith, directly underfoot, is the nadir. Latitude and longitude both start with "L" and end with "-tude," so they sound similar. At the June and December solstices, the Sun is overhead at the Tropics of Cancer and Capricorn, respectively. Well-known Text ( WKT) formats. Science Earth Science, Geologic Time & Fossils Earth Sciences. Earth Coordinates Locate a point in Earth As you know, the Earth is a sphere, or at least it’s very similar to a sphere. You will be able to describe how the locations of celestial objects are stated in the coordinate systems of the celestial sphere. welcome to cernerworks 'the directions') [1] is the. Latitudes range from 0° at the Equator to 90° at the poles. Coordinates are linear and/or angular quantities that designate the position of a point in relation to a given reference frame. Latitude measures north-south position, while longitude measures east-west position. Science Earth Science, Geologic Time & Fossils Earth Sciences. National Atlas explains that geographic coordinates pinpoint a location’s. Foucault followed up in 1852 with a gyroscope experimentto further demonstrate the Earth's rotation. studio flat to rent bills included harlow [1] It is the simplest, oldest and most widely used of the various spatial reference systems that are in use, and forms the basis for most others. The direction of the Sun (yellow arrow) is an important direction for many situations involving space weather near Earth. In today’s digital age, finding our way around has become much easier thanks to the availability of advanced technology. Physical science is a natural science and includes astronomy, physics, chemistry and earth sciences. Weather abounds with ideas for science pro. It is a system of latitude and longitude coordinates that defines a three-dimensional position of a point on the Earth’s surface.
Enter Search Criteria. (1) where R is the Earth's radius, R = 6371 Since this cartesian coordinate system is fixed with the Earth, it is call Earth-centered Earth. The latitude-longitude coordinate system is well suited for global applications because it provides a straightforward way to specify any point on the Earth's surface. The parametric latitude or reduced latitude, β, is defined by the radius drawn from the centre of the ellipsoid to that point Q on the surrounding sphere (of radius a) which is the projection parallel to the Earth's axis of a point P on the ellipsoid at latitude ϕ. Earth’s latitudes experience the solstices in different ways. The Earth’s Coordinate System (Latitude and Longitude) The first step in converting the information contained in the real–world onto a ‘piece of paper’ was to devise a system where everything could be uniquely located in the world. Latitude measures north-south position, while longitude measures east-west position. Geospatial data is information that describes objects, events or other features with a location on or near the surface of the earth. The point 180° opposite the zenith, directly underfoot, is the nadir. Longitude is the angular distance of a place east or west of the meridian at Greenwich, England, or west of the standard meridian of a celestial object. These lines run from the North Pole to the South Pole and help measure the east-west position of a location. Many organizations use geodesy to map the U shoreline, determine land boundaries, and improve transportation and navigation safety. [1] Datums [note 1] are crucial to any technology or. northeast regional 148 There are also coordinate systems needed specifically in astronomical and satellite positioning, which are not appropriate to describe positions of terrestrial points in. b =+90 ° at the NEP and b =-90 ° at the SEP. Jun 16, 2024 · latitude and longitude, in cartography, a coordinate system used to determine and describe the position of any place on Earth ’s surface. astronomical map, any cartographic representation of the stars, galaxies, or surfaces of the planets and the Moon. Planetary and Space Science, 40, 711-717 T Geophysical coordinate transformations. Earth’s axis of rotation orients latitude so that … A coordinate system is a reference system used to represent the locations of geographic features, imagery, and observations, such as Global Positioning System … Geodesy or geodetics [1] is the science of measuring and representing the geometry, gravity, and spatial orientation of the Earth in temporally varying 3D. Developmental coordination disorder is a childhood disorder. These lines are not parallel, so they are furthest apart at the equator and. Space weather refers to the conditions in space that can have an impact on Earth and our technologies. Longitude is the distance east or west of the Prime Meridian and is expressed as a number between 0 and 180 degrees east or west. Balance and coordination are important skills for athletes, dancers, and anyone who wants to stay active. Geocentric Coordinate. Until the advent of satellites, all geodesic work was based on land surveys made by triangulation methods employing a geodesic coordinate system (one used to study the geometry of curved surfaces). Geodesy is an earth science as well as a discipline of applied mathematics, and many consider the study of Earth's shape and gravity to be central to the science. Field Definition: The year, day, minute, and seconds in which the satellite was turned on for swath acquisition. rule 34 comcis Kids science is such a blast when you mix and reuse everyday materials to see what happens. Right ascension (RA) is the celestial equivalent of longitude. Horizontal and vertical units:The units used to define the grid along the x, y (and z) axis. However, there is an international agreement that the meridian that runs through Greenwich, England, is considered the. The UTM system consists of 60 zones, each 6-degrees of longitude in width. Is there a name like "Spherical" that I can use to work with the Earth science convention? If not, can I define a new coordinate. For example, on Earth, this situation occurs for a body at the equator moving north or south relative to the Earth's surface. The northern lights occur when charged particles fro. “Coordinated Inauthentic Behavior,” a phrase coined by Facebook, is the use of m. ecliptic, in astronomy, the great circle that is the apparent path of the Sun among the constellations in the course of a year; from another viewpoint, the projection on the celestial sphere of the orbit of Earth around the Sun. They describe how (1) planets move in elliptical orbits with the Sun as a focus, (2) a planet covers the same … The current IAU definition of "planet" is problematic because it is vague and excludes exoplanets. Longitude is the distance east or west of the Prime Meridian and is expressed as a number between 0 and 180 degrees east or west. You will be able to describe how the locations of celestial objects are stated in the coordinate systems of the celestial sphere. Figure 113 1: The Geographic Grid: Latitude and Longitude (Courtesy The National Atlas) Latitude and longitude comprises a grid system of lines encircling the globe and is used to determine the locations of points on the earth. The deviation of the compass from true north is an angle called "declination" (or "magnetic declination"). meridian, imaginary north–south line on the Earth’s surface that connects both geographic poles; it is used to indicate longitude. parallel, imaginary line extending around the Earth parallel to the equator; it is used to indicate latitude. longitude and latitude coordinates are usually expressed in degrees and minutes. In astronomy, declination (abbreviated dec; symbol δ) is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle.