Como Calcular Latitude E Longitude?

What is Earth’s latitude?

Latitude lines start at the equator (0 degrees latitude) and run east and west, parallel to the equator. Lines of latitude are measured in degrees north or south of the equator to 90 degrees at the North or South poles. A transcript is available that describes this infographic content in plain text.

  • Image credit: iStock) Lines of latitude, also called parallels, are imaginary lines that divide the Earth.
  • They run east to west, but measure your distance north or south.
  • The equator is the most well known parallel.
  • At 0 degrees latitude, it equally divides the Earth into the Northern and Southern hemispheres.

From the equator, latitude increases as you travel north or south, reaching 90 degrees at each pole.

What is longitude in simple terms?

Prime Meridian vs. International Reference Meridian – Unlike the equator (which is halfway between the Earth’s north and south poles), the prime meridian is an arbitrary line. In 1884, representatives at the International Meridian Conference in Washington, D.C., met to define the meridian that would represent 0 degrees longitude.

  1. For its location, the conference chose a line that ran through the telescope at the Royal Observatory in Greenwich, England.
  2. At the time, many nautical charts and time zones already used Greenwich as the starting point, so keeping this location made sense.
  3. But, if you go to Greenwich with your GPS receiver, you’ll need to walk 102 meters (334 feet) east of the prime meridian markers before your GPS shows 0 degrees longitude.

In the 19th century, scientists did not take into account local variations in gravity or the slightly squished shape of the Earth when they determined the location of the prime meridian. Satellite technology, however, allows scientists to more precisely plot meridians so that they are straight lines running north and south, unaffected by local gravity changes.

In the 1980s, the International Reference Meridian (IRM) was established as the precise location of 0 degrees longitude. Unlike the prime meridian, the IRM is not a fixed location, but will continue to move as the Earth’s surface shifts. Lines of longitude, also called meridians, are imaginary lines that divide the Earth.

They run north to south from pole to pole, but they measure the distance east or west. The prime meridian, which runs through Greenwich, England, has a longitude of 0 degrees. It divides the Earth into the eastern and western hemispheres. The antimeridian is on the opposite side of the Earth, at 180 degrees longitude.

Though the antimeridian is the basis for the international date line, actual date and time zone boundaries are dependent on local laws. The international date line zigzags around borders near the antimeridian. Like latitude, longitude is measured in degrees, minutes, and seconds. Although latitude lines are always equally spaced, longitude lines are furthest from each other at the equator and meet at the poles.

At the equator, longitude lines are the same distance apart as latitude lines — one degree covers about 111 kilometers (69 miles). But, by 60 degrees north or south, that distance is down to 56 kilometers (35 miles). By 90 degrees north or south (at the poles), it reaches zero.

Navigators and mariners have been able to measure latitude with basic tools for thousands of years. Longitude, however, required more advanced tools and calculations. Starting in the 16th century, European governments began offering huge rewards if anyone could solve “the longitude problem.” Several methods were tried, but the best and simplest way to measure longitude from a ship was with an accurate clock.

A navigator would compare the time at local noon (when the sun is at its highest point in the sky) to an onboard clock that was set to Greenwich Mean Time (the time at the prime meridian). Each hour of difference between local noon and the time in Greenwich equals 15 degrees of longitude.

Why? Because the Earth rotates 360 degrees in 24 hours, or 15 degrees per hour. If the sun’s position tells the navigator it’s local noon, and the clock says back in Greenwich, England, it’s 2 p.m., the two-hour difference means the ship’s longitude is 30 degrees west. But aboard a swaying ship in varying temperatures and salty air, even the most accurate clocks of the age did a poor job of keeping time.

It wasn’t until marine chronometers were invented in the 18th century that longitude could be accurately measured at sea. Accurate clocks are still critical to determining longitude, but now they’re found in GPS satellites and stations, Each GPS satellite is equipped with one or more atomic clocks that provide incredibly precise time measurements, accurate to within 40 nanoseconds (or 40 billionths of a second).

The satellites broadcast radio signals with precise timestamps. The radio signals travel at a constant speed (the speed of light), so we can easily calculate the distance between a satellite and GPS receiver if we know precisely how long it took for the signal to travel between them. On the ground, NOAA’s National Geodetic Survey manages the Continuously Operating Reference Stations Network, which comprises 1,800 stationary, permanently operating GPS stations.

These CORS continuously receive GPS radio signals and incorporate that data into the National Spatial Reference System, The GPS position on a smartphone is accurate to within about 5 meters (16 feet), but processed CORS data can provide longitude accurate to within a few centimeters, along with latitude and height positions.

How do I find the latitude and longitude of my location on my phone?

Determining Your Site’s Latitude and Longitude If you have adequate reception at your site, you can use your phone to determine your latitude and longitude.

iPhone: Android: Open Google Maps; it will zoom to your approximate location. Press and hold on the screen to drop a pin marker. Click on the dropped pin; latitude and longitude will be displayed below the map. If you don’t have Google Maps, you can before heading to your site.

If you don’t have adequate cellular reception at your site to use the methods above, you can determine your site’s latitude and longitude when you get back to your computer. If you are sharing your data on the data portal, during the site registration process you can zoom in on the map, click to place a pin at your deployment location, and the lat/long will be auto-generated.

What is the longest latitude?

The equator has the longest latitude. It is located at 0° latitude. – Suggest Corrections 3 Similar questions Q. The Tropic of Capricorn is located at which latitude? Q. Which is the longest latitude Q. Which latitude is the longest? Q. Which of the following latitudes is the longest? Q. Which latitude passes through Australia? View More Join BYJU’S Learning Program Select. Related Videos Latitudes and Longitudes SOCIAL SCIENCE Watch in App Explore more Latitudes and Longitudes Standard IX Social Science

What are the 5 difference between latitude and longitude?

The main difference between latitude and longitude is: Latitude is horizontal, and Longitude is vertical. Latitude measures heat zones, and longitude measures time zones. Latitudes are parallel lines, whereas Longitudes are called Meridians.

How do you explain latitude and longitude to a child?

Latitude and longitude are a system of lines used to describe the location of any place on Earth. Lines of latitude run in an east-west direction across Earth. Lines of longitude run in a north-south direction. Although these are only imaginary lines, they appear on maps and globes as if they actually existed.

What is 0 longitude called?

Prime Meridian vs. International Reference Meridian – Unlike the equator (which is halfway between the Earth’s north and south poles), the prime meridian is an arbitrary line. In 1884, representatives at the International Meridian Conference in Washington, D.C., met to define the meridian that would represent 0 degrees longitude.

For its location, the conference chose a line that ran through the telescope at the Royal Observatory in Greenwich, England. At the time, many nautical charts and time zones already used Greenwich as the starting point, so keeping this location made sense. But, if you go to Greenwich with your GPS receiver, you’ll need to walk 102 meters (334 feet) east of the prime meridian markers before your GPS shows 0 degrees longitude.

In the 19th century, scientists did not take into account local variations in gravity or the slightly squished shape of the Earth when they determined the location of the prime meridian. Satellite technology, however, allows scientists to more precisely plot meridians so that they are straight lines running north and south, unaffected by local gravity changes.

  1. In the 1980s, the International Reference Meridian (IRM) was established as the precise location of 0 degrees longitude.
  2. Unlike the prime meridian, the IRM is not a fixed location, but will continue to move as the Earth’s surface shifts.
  3. Lines of longitude, also called meridians, are imaginary lines that divide the Earth.

They run north to south from pole to pole, but they measure the distance east or west. The prime meridian, which runs through Greenwich, England, has a longitude of 0 degrees. It divides the Earth into the eastern and western hemispheres. The antimeridian is on the opposite side of the Earth, at 180 degrees longitude.

  1. Though the antimeridian is the basis for the international date line, actual date and time zone boundaries are dependent on local laws.
  2. The international date line zigzags around borders near the antimeridian.
  3. Like latitude, longitude is measured in degrees, minutes, and seconds.
  4. Although latitude lines are always equally spaced, longitude lines are furthest from each other at the equator and meet at the poles.

At the equator, longitude lines are the same distance apart as latitude lines — one degree covers about 111 kilometers (69 miles). But, by 60 degrees north or south, that distance is down to 56 kilometers (35 miles). By 90 degrees north or south (at the poles), it reaches zero.

Navigators and mariners have been able to measure latitude with basic tools for thousands of years. Longitude, however, required more advanced tools and calculations. Starting in the 16th century, European governments began offering huge rewards if anyone could solve “the longitude problem.” Several methods were tried, but the best and simplest way to measure longitude from a ship was with an accurate clock.

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A navigator would compare the time at local noon (when the sun is at its highest point in the sky) to an onboard clock that was set to Greenwich Mean Time (the time at the prime meridian). Each hour of difference between local noon and the time in Greenwich equals 15 degrees of longitude.

  • Why? Because the Earth rotates 360 degrees in 24 hours, or 15 degrees per hour.
  • If the sun’s position tells the navigator it’s local noon, and the clock says back in Greenwich, England, it’s 2 p.m., the two-hour difference means the ship’s longitude is 30 degrees west.
  • But aboard a swaying ship in varying temperatures and salty air, even the most accurate clocks of the age did a poor job of keeping time.

It wasn’t until marine chronometers were invented in the 18th century that longitude could be accurately measured at sea. Accurate clocks are still critical to determining longitude, but now they’re found in GPS satellites and stations, Each GPS satellite is equipped with one or more atomic clocks that provide incredibly precise time measurements, accurate to within 40 nanoseconds (or 40 billionths of a second).

The satellites broadcast radio signals with precise timestamps. The radio signals travel at a constant speed (the speed of light), so we can easily calculate the distance between a satellite and GPS receiver if we know precisely how long it took for the signal to travel between them. On the ground, NOAA’s National Geodetic Survey manages the Continuously Operating Reference Stations Network, which comprises 1,800 stationary, permanently operating GPS stations.

These CORS continuously receive GPS radio signals and incorporate that data into the National Spatial Reference System, The GPS position on a smartphone is accurate to within about 5 meters (16 feet), but processed CORS data can provide longitude accurate to within a few centimeters, along with latitude and height positions.

Which line is at 0 latitude?

Latitude lines start at the equator (0 degrees latitude) and run east and west, parallel to the equator. Lines of latitude are measured in degrees north or south of the equator to 90 degrees at the North or South poles. A transcript is available that describes this infographic content in plain text.

Image credit: iStock) Lines of latitude, also called parallels, are imaginary lines that divide the Earth. They run east to west, but measure your distance north or south. The equator is the most well known parallel. At 0 degrees latitude, it equally divides the Earth into the Northern and Southern hemispheres.

From the equator, latitude increases as you travel north or south, reaching 90 degrees at each pole.

What are the two main longitudes?

What are the two main longitudes? Answer at BYJU’S IAS The two main longitudes are the Prime Meridian and the 180° meridian. The two longitudes divide the earth into two equal halves, the Eastern Hemisphere and the Western Hemisphere. Therefore, the longitude of a place is followed by the letter E for the east and W for the west. : What are the two main longitudes? Answer at BYJU’S IAS

Is latitude or longitude first?

Where am I? – To chart your position there are two co-ordinates you need:

Latitude – Lines of latitude run in horizontal parallels and represent distance north or south from the equator, measured in an angle from the centre of the Earth. The equator represents 0° and each pole represents 90°. Each degree of latitude corresponds with 60 nautical miles, or 111.1 kilometres, on the Earth’s surface. Longitude – Lines of longitude, called meridians, run vertically from pole to pole. They represent the distance east or west from Greenwich in London, England. Greenwich is the prime meridian and corresponds to 0°, while the International Date Line is where east and west meet again, at 180°.

Handy tip: when giving a co-ordinate, latitude (north or south) always precedes longitude (east or west). Latitude and longitude are divided in degrees (°), minutes (‘) and seconds (“). There are 60 minutes in a degree and 60 seconds in a minute (similar to measuring time).

  • The Sydney Opera House’s latitude and longitude are given as 33° 51′ 30″ S, 151° 12′ 53″ E – meaning it lies 33 degrees, 51 minutes and 30 seconds south of the equator and 151 degrees, 12 minutes and 53 seconds east of Greenwich.
  • Terrella is a small, magnetised globe with the lines of longitude and latitude engraved on both the globe and the outer case.

Image: National Maritime Museum, London.

Is latitude north and south?

Latitude lines start at the equator (0 degrees latitude) and run east and west, parallel to the equator. Lines of latitude are measured in degrees north or south of the equator to 90 degrees at the North or South poles. A transcript is available that describes this infographic content in plain text.

Image credit: iStock) Lines of latitude, also called parallels, are imaginary lines that divide the Earth. They run east to west, but measure your distance north or south. The equator is the most well known parallel. At 0 degrees latitude, it equally divides the Earth into the Northern and Southern hemispheres.

From the equator, latitude increases as you travel north or south, reaching 90 degrees at each pole.

How do you use a GPS system?

Download Article Download Article GPS, or Global Positioning System, devices seem to be everywhere these days—on your phone, in your car, and attached to many of your favorite apps. You can use your GPS to get directions and find new places to eat and play, but learning how to use one can seem complicated thanks to the variety of different GPS styles.

  1. The GPS market is flooded with different devices, options, and features. Unless you plan on using your GPS in the wilderness or for research experiments, however, your smart phone or a car GPS, can provide directions and your location quickly and easily. Most have touch screens and come with a rechargeable battery.
    • Smart Phones: Most smart phones come pre-loaded with a “Maps,” or “Directions” app that uses GPS. If you do not have one, search and download an app, like Google Maps, from your app store to use GPS.
    • GPS Devices: These are small, rectangular devices that specialize in driving directions and finding restaurants, airports, and other points of interest. Examples include TomTom and Garmin, and most cost under $170 dollars.
  2. This is the basic screen for a GPS. It shows a location, usually with your current location at the center, and all of the roads and major landmarks nearby. Advertisement
  3. Some GPS use touch screens, others have keypads, and some have scroll wheels and buttons. Click on the button labeled with a compass, navigational arrow, or crosshairs to show your current location.
    • Your location is sometimes stored under the heading “Where am I?” “Favorite Locations,” or “Current.”
    • iPhone users can see their current location using the built-in Compass App. Make sure you “Allow Location Services” for the compass under “Settings” → “Privacy” → “Location Services” → “Compass”
  4. Using the search bar found at the top of your GPS, type in the address you want to reach. Many touch screen GPS’s let you choose a location by holding your finger on the location in the map.
    • Some GPS’s will prompt you with a button labeled “Get Directions.” Choose this if there is no search bar to input an address.
    • If you know the exact latitude and longitude of your trip, use these; they will give you the most accurate location possible.
  5. The GPS will give you directions at every turn you need to take. Don’t worry if you miss a turn – most GPS will auto-correct and give you a new route to get back on track.
    • If you are struggling to keep up, check your GPS’s settings and make the “Turn Warning Frequency” setting longer – giving you more time to hear the next direction.
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  1. Latitude and longitude are represented by numbers, known as degrees, which measure your distance from two “zero lines.” Longitude measures your distance East or West of the prime meridian, and latitude measure your distance North or South of the equator. This is the most accurate system of measurement for your GPS.
    • An example (guess where it is!), is 37°26’46.9″N, 122°09’57.0″W.
    • Sometimes direction is noted by positive or negative numbers. North and East are considered positive. The previous example could be written as: 37°26’46.9″, -122°09’57.0″
    • If there is no notation, know that the latitude always comes first.
  2. Waypoints are saved in the GPS to be viewed later, allowing you to take notes, draw maps, and keep information on the landscape easily. On your GPS, click “Save Location,” “Add to Favorites,” or “Mark Waypoint.”
    • Complex scientific GPS systems often let you mark specific waypoints – artifacts, streams, rock formations, etc.
    • The more points your save into your GPS, the more accurate your map of the area when you get home.
  3. Plug in the longitude/latitude coordinates of water sources, campgrounds, or ranger stations under “Get Directions” or “Find Location,” then save them by clicking “Add to Favorites.” You can now access it anytime.
    • “Add to Favorites” might be labeled by a star or flag as well.
    • Click “Saved Locations” or “Favorite Locations” to see you waypoints anytime. You can click on them to get directions from anywhere in the world.
  4. Most complex GPS systems come with software that lets you save your data onto your computer. The program will import your way points and use them to make a map of the area you were in, complete with elevation data and any notes you made on your GPS.
    • If you are mapping a specific area, make as many waypoints as you can for an accurate map. The more data the program has, the better the final product.
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  1. If you are using a phone this will happen automatically, but some GPS devices need to be manually updated. This will give you the latest information, topography, and directions.
    • Find the “About” button, usually located in “Settings.”
    • Scroll down to see Map Information. If this is more than 6 months old, you will need to update.
    • Plug your GPS into an internet-enabled computer using the cord that came with the unit.
    • Perform an internet search for “your GPS + Map Update” follow the onscreen instructions.
  2. There are over 25 satellites orbiting earth that receive signals from your GPS and use those signals to determine your latitude and longitude. Developed by the army, GPS can accurately tell your location anywhere in the world by several feet – as long as the signal can reach the satellites.
    • Cell phone GPS uses cell towers and internet signals to find your location, so they won’t work in the wilderness.
  3. GPS needs a clear view of the sky to accurately communicate with the satellite’s, so move away from overhangs or tall trees and head outside if you have issues. Generally, if you can see the sky, the GPS can as well.
    • Tunnels, caves, and basements may all keep your GPS from communicating to satellites and working successfully.
  4. Most GPS devices are built in Asia, and are used to communicating with satellites over that area. Initializing your GPS acquaints it with your local area. To initialize a GPS, go to “Settings” and click “Initialize.” Follow your GPS’s manual if you have any problems finding the setting, and know that this may take up to 20 minutes.
    • Turn your GPS off and restart it if you are having problems.
    • Make sure you have a clear view of the sky.
    • You may need to reset your GPS the first time you buy it by clearing the memory. Refer to the manual for instructions.
  5. This is especially useful when hiking. In the parking lot, find your GPS’s satellite lock setting and have it get to work – it usually takes several minutes.
    • Signs that you have a bad signal are changing directions, jittery locations, or error messages.
  6. Because a GPS can run out of battery, lose signal, or break, you should never rely on it completely to get around. While useful, you need to be prepared in case you cannot use it for some reason.
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  1. Most GPS devices can find much more than addresses these days. Try searching “Indian Food,” “Post Offices,” “Gas,” “Rock Climbing Gyms,” or whatever else you are interested in and see what pops up. This can be incredibly useful when you are in a new city, or if you just feel like finding the closest burrito shop.
    • Apps and Internet enabled GPS (like those found on phones) will always have this feature.
    • Many portable GPS devices have a section labeled “Nearby Locations” or “Find Locations” that list businesses within a short radius of your current location.
  2. Have fun Geocaching. Geocaching is when people hide objects in the world with GPS coordinates. It is a global community that prides itself on sharing and exploration, and can be a great way to see the outdoors. To Geocache, buy a GPS and sign up for one of the many internet-based services and forums.
  3. Most modern GPS devices and apps can be turned on while you run or bike, and store the information on your speed, elevation, and distance for later. You will need a specific app like NikeFit, MapMyRun, or AppleHealth to get the most out of this feature.
  4. Find a lost phone. Because smartphones are constantly hooked up to a GPS, you can use them to find lost or stolen phones if you act quickly. Download a tracking app on for your phone and sync it with your computer to always keep tabs on your phone’s location.
    • Use “Find my iPhone,” by going to the Find my iPhone Website and inputting your Apple username.
    • Log onto Google’s online “Device Manager” to find your lost/stolen android phone without a tracking app. You can even download “Android Lost” to your phone remotely to get your phone’s coordinates.
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Add New Question

  • Question How can I use GPS using the Internet? Download a maps app from your phone app store. There are plenty of them, and some even allow offline maps for when you lack an Internet connection.
  • Question Can a GPS alert me to cars in the lane next to me if I want to move into that lane? No. GPS gives you directions, it doesn’t tell you what cars are in the next lane.
  • Question How do I use Google Maps on a desktop? Open your web browser and go to maps.google.com.

Ask a Question 200 characters left Include your email address to get a message when this question is answered. Submit Advertisement

  • The GPS allows serves you better to get to your destination better than looking at the map then turn because you will have to stop and look at the map if you are the only person who is driving and nobody driving inside your car.
  • Your cell phone may have a GPS/navigator, so use it if you can. It should be operated the same way as a standard GPS.
  • Go to expert-village’s Channel on YouTube to learn more how to use a GPS.

Show More Tips Advertisement

  • Take care of the GPS – it is expensive thing and you will pay expensive price to fix it or get a new one.
  • Always use common sense when using a GPS, and have a backup method of navigation ready.

Advertisement Article Summary X To use a GPS, select the search bar and enter the address you want to find. Alternatively, search using keywords to get suggestions, like “Indian food” or “rock climbing gym. Make sure that you’re standing in an open space while you perform your search so the device can pick up a signal.

Once you’ve found what you’re looking for, follow the on-screen instructions to get to your chosen location. Don’t worry if you miss one of the directions, since most GPS systems will auto-correct as you go. If you want to find your current location, press the button marked with crosshairs, a compass, or navigation arrow.

You can also use your GPS system to track down a lost phone or monitor your workouts. For tips on how to update your GPS map, keep reading! Did this summary help you? Thanks to all authors for creating a page that has been read 87,591 times.

Which country has more latitude?

Originally Answered: Which country spans the most degree of latitude? It is Chile the long thin country in the southwest corner of South America. It spans from 17° degrees south (near Arica) to 55° degrees south (Cape Horn). It spans more than places like the contiguous United States, Canada, Russia or Australia.

Which countries have longest latitude?

Chile is the world’s longest country from north to south with 2,647 miles long and spreads through 38 degrees of latitude. The geography of Chile is very diverse as the country extends from the latitude of 17 degrees south to Cape Horn to 56 degrees and from the Ocean on the west to the Andes on the East.

How many longitudes are there?

Out of 179 western longitudes, 179 eastern longitudes, 1 GMT line, and 1 (0 °) longitude line, the total number of longitudes is 360. The 180 ° longitude line is sometimes called the International Date Line.

Why there are 24 lines of longitude?

Development and History of Longitude – For centuries, mariners and explorers worked to determine their longitude in an effort to make navigation easier. Latitude was determined easily by observing the inclination of the sun or the position of known stars in the sky and calculating the angular distance from the horizon to them.

  • Longitude could not be determined in this way because Earth’s rotation constantly changes the position of stars and the sun.
  • The first person to offer a method for measuring longitude was the explorer Amerigo Vespucci,
  • In the late 1400s, he began measuring and comparing the positions of the moon and Mars with their predicted positions over several nights at the same time ( diagram ).

In his measurements, Vespucci calculated the angle between his location, the moon, and Mars. By doing this, Vespucci got a rough estimate of longitude. This method did not become widely used however because it relied on a specific astronomical event. Observers also needed to know the specific time and measure the moon and Mars’ positions on a stable viewing platform- both of which were difficult to do at sea.

In the early 1600s, a new idea to measure longitude was developed when Galileo determined that it could be measured with two clocks. He said that any point on Earth took 24 hours to travel the full 360° rotation of Earth. He found that if you divide 360° by 24 hours, you find that a point on Earth travels 15° of longitude every hour.

Therefore, with an accurate clock at sea, a comparison of two clocks would determine longitude. One clock would be at the home port and the other on the ship. The clock on the ship would need to be reset to local noon each day. The time difference would then indicate the longitudinal difference traveled as one hour represented a 15° change in longitude.

Can latitude and longitude be same?

Latitude and Longitude are Not Enough A given latitude and longitude location would always mean the same thing only if the Earth was a perfectly round, unchanging sphere, which it is not. Instead, the Earth is an irregular, lumpy ellipsoid with a shape that changes over time due to geologic action.

  1. The irregular shape of the Earth usually can be approximated fairly well to map a particular region of interest by assuming the surface in that region is part of a smooth ellipsoid which is positioned at some offset from whatever is considered to be the center of the Earth.
  2. See the topic.
  3. The exact values of latitude and longitude that specify a particular location on Earth depend on which size, shape and placement of ellipsoid we use to represent the surface of the Earth in the region of interest.

The exact, same location on Earth can have different latitude and longitude numbers depending on which ellipsoid is being used and how that ellipsoid is used. Conversely, the exact location specified by a given pair of latitude and longitude coordinates, such as a longitude of -96.65435872972012 and a latitude of 33.12971033155918, depends on what ellipsoid is being used and how. We can plot the latitude and longitude location of the In-N-Out restaurant in Allen, Texas, in two different layers using two different ellipsoids for the layers, one layer showing a green icon for the position and the other layer using a blue icon for the layer.

  • In both cases the longitude and latitude numbers are identical but the ellipsoids are different with the name of the ellipsoid used being shown beneath the latitude and longitude numbers.
  • The WGS84 ellipsoid is a good match to the “automatic” WGS84 ellipsoid used by most web mapping servers, so the position it shows for the geocoded longitude and latitude of the restaurant is a reasonably close match to the position shown in the Open Street Maps base map layer.

Slight mismatches like that are typical when plotting geocoded addresses because the geocoding software used to determine the latitude and longitude of a given address might not match exactly precise maps of features on the ground that are created based on satellite or aerial photos.

  1. As anybody knows who has searched for a street address using a car’s GPS navigator, the positions shown for addresses are usually just approximations.
  2. The blue location icon using the Everest 1830 (India) ellipsoid shows the identically same latitude and longitude numbers when plotted on the Everest 1830 (India) ellipsoid.

The coordinate pair using that ellipsoid appears in a very different position, about 200 meters / yards away from the green icon, because the Everest 1830 (India) ellipsoid is shaped and positioned not to be a good match to the Earth’s surface in Texas but instead to be a good match to what the Earth’s surface in the Indian Himalayas was thought to be in 1830.

We chose that ellipsoid because while in 1830 it was considered a good match to the surface of the Earth in the vicinity of Mount Everest when measured from India, the surface of that ellipsoid does not particularly well align with the surface of the Earth in the vicinity of the In-N-Out burger restaurant in Allen, Texas.

So it shows the same lat/lon numbers in a visibly different location. To understand what we see in the illustration above, and to understand how two different dots in what appears to be the same map can have exactly the same coordinates down to the 14th decimal point, we should first understand that what we see in the illustration above is a sandwich of three layers that consist of three different maps in three different coordinate systems.

We are looking through three semi-transparent surfaces of ellipsoids displayed together, and the ellipsoids do not quite line up. So exactly the same coordinates on those three not-quite-lined-up ellipsoids do not line up either when we see them visually stacked together. One surface is the base map at the bottom with roads and parking lot.

The second surface is transparent but for the green dot on it and the third surface is also transparent but for the blue dot on it. If the second and third surfaces had grids drawn on them the green dot and the blue dot would both be graphed at the same numbers on those grids.

Think of the second and third surfaces as transparent layers of graph paper that are slightly displaced from each other. Because the second and third surfaces are displaced from each other a bit, when we look at the two surfaces together we see dots plotted at exactly the same grid locations on each sheet but since the sheets are displaced the dots are slightly apart from each other.

Another way to think of this is to imagine the green dot drawn on a transparent balloon and the blue dot is also drawn on a transparent balloon, with both dots drawn at exactly the same latitude and longitude locations in their respective balloons. If we put one balloon inside the other and then move it just a bit relative to the other balloon the two dots will not quite line up, because the balloon surfaces on which they are drawn will be slightly offset.

  • Each dot will be at exactly the same latitude and longitude location on its respective balloon, but because the balloon surfaces are offset if we look down through the transparent balloons the two dots will not quite line up.
  • In this case the “green dot balloon” surface is the ellipsoidal surface that has been sized and positioned so it is a better fit to the actual surface of the Earth in the vicinity of Texas.

The “blue dot balloon” ellipsoidal surface has been sized and positioned so it is a better fit to the actual surface of the Earth in the vicinity of Mount Everest, on the other side of the planet. Therefore, exactly the same latitude and longitude coordinates marked on the “blue balloon” surface on the Texas side of the planet do not line up exactly with points marked on the “green balloon” surface that has been positioned so it is more flush with the actual surface of the planet in Texas.

  1. Both sets of numbers are precisely alike in that they both mark exactly the same latitude and longitude on their respective “balloon” surfaces.
  2. But because the “blue balloon” surface using the Everest ellipsoid has been nudged a bit toward Mount Everest so it aligns better there, the exact same relative spot on it as on the “green balloon” appears about 200 meters / yards away from the same spot marked on the “green balloon.” The “green balloon” surface is better aligned to the surface in Texas so it is a closer match to other maps, like the Open Street Maps base layer, used in Texas.

Note that neither the green dot nor the blue dot fall exactly on the location of the In-N-Out restaurant in Allen, Texas, as shown in the Open Street Maps layer. The green dot is closer but still does not exactly align with the OSM layer. That usually occurs when geocoding software, which is software that attempts to assign a latitude, longitude location to a given street address, estimates the position of a given street address using rules of thumb like approximate spacing of addresses along a street.

When the rules of thumb do not match the exact location of addresses the locations given by the geocoder for addresses will be slightly off. The latitude and longitude locations for In-N-Out restaurants used in this documentation were obtained by running the street addresses of all In-N-Out restaurants through an on-line geocoder to generate an estimated geographic location for each address.

The idea that each address can be known to 14 decimal points of latitude or longitude degrees is absurd, but that is what the geocoder spits out as an estimate. The green dot is the closest match to the OSM layer because they both use the same ellipsoid, the WGS84 ellipsoid, but they are slightly off because the geocoder estimated the location of the restaurant address along East Stacy Road at a slightly different location than it is in real life.

The moral of all the above? Latitude and longitude numbers have meaning only within the context of a specific Earth ellipsoid. Specifying only latitude and longitude numbers by themselves is not enough. We must also specify which Earth ellipsoid, that is, which datum, was used to measure those numbers.

Given the popularity of the WGS84 ellipsoid as a default in many GPS devices, telephones and other consumer gadgets we could do worse than to assume that lat/lon numbers we encounter with no accompanying ellipsoid were measured using WGS84. But if accuracy is important we should make the effort to find out for certain which ellipsoid was used.

What is the distance between two longitudes in KM?

A degree of longitude is widest at the equator with a distance of 69.172 miles or 111.321 Km.

How can I find my long lat without GPS?

This content is associated with The Open University’s Geography courses and qualifications, To pinpoint your position on a map of the world you need to work out your co-ordinates, known as latitude and longitude. Latitude is your position north or south of the Equator.

Lines, or parallels, are drawn around the Earth at intervals. The North Pole is assigned the latitude 90º north and the South Pole latitude 90º south. Lines of longitude, or meridians, are drawn a little differently. The line of longitude corresponding to 0º, which passes through Greenwich in London, is called the Prime (or Greenwich) Meridian.

Longitude lines run along the Earth’s surface in a north–south direction, and unlike latitude lines, they divide the globe into segments like those of an orange, rather than regular strips. A geographical globe (a) viewed from above the Equator; (b) viewed from above the North Pole How to measure latitude It’s possible to measure latitude by comparing your position on Earth with the position of either the sun or the North Star (Polaris). Measurements using the sun are possible on a clear day in the northern or southern hemispheres, when the sun is easy to find.

However, measurement of latitude isn’t as straightforward as you might think. Accurate readings can only be taken at noon, when the sun is at its highest in the sky. To complicate matters further, the sun rises higher in summer than in winter, and this must be allowed for in any calculation. Being so far away and only one of a myriad stars visible to the naked eye, the North Star isn’t as easy to find as the sun.

Furthermore, you can only see it at night, which isn’t always convenient. Its major limitation, however, is that it isn’t visible from the southern hemisphere. For our purposes, we shall therefore assume that we’re in the northern hemisphere. You can use a simple quadrant to measure latitude using either the sun or the North Star.

  1. Make a quadrant similar to the one shown here. The aiming beam needs to be pivoted about its central point so that it can swing up and down. The protractor should be centred on the pivot, from which the plumb line should be suspended. Using a compass, mark out a line on the ground that runs north to south. Make sure that your quadrant is set up so that its aiming beam is parallel to this north-south line. A quadrant for measuring latitude
  2. Measuring latitude using the sun can only be done at noon, when the sun is at its highest point in the sky. To determine when it’s noon (without a watch or radio) place a stick at the southernmost end of your north-south line. Use a plumb line to make sure that the stick is vertical. When the shadow cast by the stick crosses the north-south line, it’s noon.
  3. As soon as it’s noon, align the sighting nails on the quadrant’s aiming beam with the sun. DO NOT USE THE SIGHT LINE TO LOOK DIRECTLY AT THE SUN. Instead, watch the shadows formed by the nails on the ground as you tilt the aiming beam up and down. At first, the nails will cast two separate shadows, so move the end of the beam up or down so that these two shadows move closer together. Two shadows on the groud – beam aimed incorrectly When the shadows coincide, the beam is aimed exactly at the sun. Using the protractor, measure the smaller angle between the beam and the plumb line. One shadow – beam aimed correctly If the sun is directly over the Equator, this is your latitude reading. The angle to measure when using the sun or North Star. Note that the horizon is always 90º to the plumb line. Don’t be fooled by mountain ranges!
  4. Unfortunately, this reading is only correct on 21 March and 21 September (the spring and autumn equinoxes). At midwinter (21 December) you should deduct 23.45º from your reading, and at midsummer (21 June) add 23.45º. This is because of the way in which the ’tilted’ Earth orbits the sun. Solar declination – the seasonal consequence of the ’tilted’ Earth’s annual movement around the sun. Although complex tables (almanacs) are used to obtain correction factors for any day of the year, you can accurately estimate the appropriate numbers for yourself. For example, if calculating the value at the beginning of May, you would be half-way between the spring equinox (when the sun is directly over the Equator) and the summer solstice (when the sun is directly above a point 23.45º north of the Equator). You would therefore need to add half of 23.45º, or 11.73º, to your reading.

How do I get long and lat on Google Maps Mobile?

On Site Using a Mobile Device – If you have adequate reception at your site, you can use your phone to determine your latitude and longitude.

iPhone: Use your iPhone’s built-in GPS device Android: Open Google Maps; it will zoom to your approximate location. Press and hold on the screen to drop a pin marker. Click on the dropped pin; latitude and longitude will be displayed below the map. If you don’t have Google Maps, you can install a free GPS app before heading to your site.