Maps, Grid References, and Coordinates
Maps are a representation of a place or location, showing its geographic features. Maps show not just the physical aspects but also other information such as property boundaries and building locations.
Grid references give a way to identify a location without having to use a map.
Coordinates determine the exact position of any point on earth at any given time, from which you can locate places or features on maps.
There are two lines that appear on all maps: the vertical and horizontal lines. They always travel in a straight path and either go up and down or across the road.
Grid references are located between the lines, giving the appearance of a math square with numbers. The distinction between grid references and coordinates is that coordinates are where lines intersect, whereas grid references are in between lines.
In grid references, and we’ve learned about six figure grid references and four figure grid references. Every ordnance survey map in the world has a six-figure grid reference and a four-figure grid reference for each location.
The horizontal line is said first, followed by the vertical line. At the bottom, the horizontal line is the X axis, while the vertical line is the Y axis.
Scales let us calculate the distance to our destination and, as a result, how long it will take us to get there.
The smaller the region covered by a map, the larger the scale. If you have a map on a square meter of paper with a scale of 1:50,000 and another map on the same size paper with a scale of 1:25,000, the first map will cover four times the area covered by the second map.
Every map will include a scale, not only the number, say, 1:50,000, but also a representation of that scale. The scale of our Discovery series map is shown below.
Grids on maps have a different purpose; they aid in determining where you are on a map.
That may be because you sprained your ankle while out and about and need assistance, or because you discovered an intriguing antiquity and want to share it with a buddy.
When getting a grid reference, always read from left to right along the bottom or top of the map, then bottom to top along the side of the map.
This is especially critical in an emergency situation. If you want to be precise with your grid reference, mentally divide each side of the grid reference box into ten. This allows you to provide a six-figure grid reference.
Grid Map of the Discovery Series
Let’s create a grid reference for Lugnaquillia using the procedures below.
- Determine the letter for the 100,000-meter grid square in which the point is located. T-square grid Each lettered square’s bottom left corner begins at 0 and progresses to 100 in each direction. On the ground, each incremental square measures 1,000 meters.
- Cite the latitudes and longitudes. Locate the grid line directly to the left of the spot and read the large figures labeling the line on the map’s top or bottom edge. Then, from grid line to point, estimate in tenths. Estimation of grid line 03 022 Eastings
- Mention the Northings. Locate the grid line immediately below the spot and read the large figures labeling the line on the map’s top or bottom edge. Then, from grid line to point, estimate in tenths. Estimation of grid line 91 8. 918 degrees north.
- T 032 918 is a sample reference. The letter may be omitted for local reference.
A Discovery series map will also provide you with the center of sheet coordinates in Irish Transverse Mercator (ITM), a newly developed GPS compatible mapping projection connected with the European Terrestrial Reference System 1989. (ETRS89).
References to the Reading Grid
How To Read Ordnance Survey References to the National Grid
On an Ordnance Survey map, National Grid references are utilized to precisely pinpoint your location. A numbered grid formed by a succession of faint blue lines on each map is utilized to construct the National Grid reference.
This is a basic method for identifying points and locations on a map, which you can then provide to people as a meeting spot or quotation if you get into problems and need to clarify exactly where you are.
You may discover a variety of words used to denote National Grid references, such as ‘OS grid ref’, ‘grid reference’, ‘OS map ref’ or simply just ‘map reference’.
While the correct word is ‘National Grid reference,’ all of these terms indicate the same thing; nevertheless, as we’ll see, grid references can be supplied in a variety of formats.
The National Grid
Before we get into the specifics of the grid reference numbers, it’s vital to understand the bigger picture of the National Grid.
The Ordnance Survey divides the United Kingdom into 100 km by 100 km squares, each with its own two-letter code. The two-letter codes can be seen on Ordnance Survey maps in faint-blue capitals, as well as in the map key.
The first letter, for example, ‘S,’ denotes 500 km by 500 km squares, which are then subdivided into 25 100 km by 100 km squares, yielding ‘ST,’ ‘SU,’ ‘SO,’ and so on.
There are four primary first letters covering Great Britain: ‘S,’ ‘T,’ ‘N,’ and ‘H,’ plus a ‘O’ square covering a tiny section of North Yorkshire that is generally below tide.
This two-letter descriptor should be followed by the grid reference numbers within that square to provide a unique National Grid reference.
National Grid coordinates
The numbers that run across the map from left to right are termed eastings because they increase in value eastwards, and the numbers that run up the map from bottom to top are called northings because they increase in value northwards.
There are two primary types of grid reference:
- Four-figure grid reference, such as ‘19 45’, denotes a 1 km by 1 km square on the map; and
- Six-figure grid reference, such as ‘192 454’, shows a 100 m by 100 m square on the map.
You may also come across:
- Eight-figure grid references, such as ‘1926 4548,’ indicate a 10 m by 10 m square on the map.
- Ten-figure grid references, such as ‘19267 45487,’ show a 1 m by 1 m square on the map.
In practice, a six-digit grid reference number is most usually used, while additional digits provide a more specific position. GPS devices frequently specify grid reference numbers with at least eight digits.
Four-figure grid references
When delivering a four-figure grid reference, always offer the eastings number first and the northings number second, similar to how you would give a graph reading in school, where you would give the x coordinate first, followed by the y.
An easy way to remember this is to go along the corridor (horizontal, x axis, eastings) and then up the stairs to get the first number (vertical, y axis, northings).
Grid references in six figures
If you want to pinpoint a specific location on a map, such as your own home, you must use a six-figure grid reference. Find the square’s four-figure grid reference and write it down with a space after each pair of numbers.
Consider dividing this rectangle into 100 tiny squares, with 10 squares on each side. Remember to proceed through the corridor and up the stairs to calculate the extra digits you’ll need and enter them into your four-figure grid reference.
To avoid any ambiguity or confusion about the National Grid you’re referring to, place the two letters of the area you’re in before the digits when quoting the six-figure grid reference.
Grid reference variations
In addition to the traditional four, six, and ten-digit formats, National Grid references can be quoted in a variety of additional ways.
The grid reference for Snow don’s summit, for example, is ‘SH 609 543,’ although it may also be referred to as:
- An abbreviated number where the two National Grid letters are dropped, commonly used if the context of the grid reference is evident – ‘609 543’ or ‘609543’ on OS Landranger Map 115.
This style may also be used to quote a reference for a nearby location.
- The most exact grid reference is the entire ten-digit grid reference with National Grid letter – ‘SH 60989 54379’ or without letters ‘60989 54379’. At typical leisure map scales, these extended grid references are barely noticeable.
- The preceding numbers specify the Ordnance Survey map sheet number – for example, ’17/609543′ for OS Explorer Map OL17 or ‘115/609543’ for OS Landranger Map sheet 115.
Longitude and latitude
Using latitude and longitude is a more precise means of pinpointing the exact location of a very specific point on the earth’s surface, and it is widely utilized by satellite positioning systems and GPS devices.
A point’s latitude describes its north-south position, whereas its longitude specifies its east-west position.
You may encounter the abbreviated form of the phrases ‘Lat-long.’ Latitude and longitude references look like this: ‘50.855226 -1.402772,’ and they differ greatly from grid references, which are typically used to determine points on an Ordnance Survey map.
How do I find a grid reference on a map?
- Begin on the left side of the map and work your way east until you reach the bottom-left corner of the desired square. Make a note of this number.
- Continue north until you reach the bottom-left corner of the desired square. Make a note of this number.
- Take an east-west direction and continue on the map until you reach the top-left corner of the desired square. Make a note of this number.
- Continue north to where you were, and so on.
Can you put grid references into Google Maps?
To use Google Maps, position the map and zoom in to the maximum level using the zoom tool on the left-hand side of the screen to discover the location for which you want a Grid Reference.
Then, either click “Grid Reference Tools” and select “Get Grid Reference from Map” or click “Grid Reference Tools” and select “Get Grid Reference from Map.” If a place name is found, the map will center on it.
What is 4 figure grid reference?
A four-figure grid reference has four numbers. For instance, you could be given the number 3422.
The first two numbers are known as the easting, and they are the numbers that you would seek for at the bottom of the map. Your granddad provides you with the four-digit grid reference 1331.
How many digits is a grid reference?
A grid reference is a four- or six-digit number that represents a specific position on a map. The grid reference is determined by the eastings and northings. Eastings are distances measured to the east. They are analogous to the x-axis on a graph.
How do you write coordinates?
Begin with your latitude line, writing the degrees, then the minutes, and finally the seconds. Then, as the direction, enter North or South.
Then, after a comma, put your line of longitude in degrees, minutes, and seconds. Then, as the direction, enter East or West.
What is the golden rule for finding a grid reference?
The golden rule for reading grid references is to always start at the bottom of the X axis and record the numbers first, then travel up the side and record the numbers second.
‘Along the corridor and up the stairs,’ says the narrator. Six Figure grid references allow you to pinpoint a certain location on a map.
How do you convert XY coordinates to latitude and longitude?
This is the scientifically determined radius of the Earth. Use the formulas to calculate latitude and longitude: latitude = asin (z/R) and longitude = atan2 (x, y).
What are Northing and Easting coordinates?
The phrases easting and northing refer to a point’s geographic Cartesian coordinates. The eastward-measured distance (or the -coordinate) is referred to as easting, while the northward-measured distance is referred to as northing (or the -coordinate).
Ordinarily, orthogonal coordinate pairs are measured in meters from a horizontal datum.
How can I acquire Google Maps GPS coordinates?
How to Locate Coordinates in Google Maps on a Mobile Device
- On your iPhone or Android device, launch the Google Maps app.
- Enter the coordinates for the location, or select and hold to drop a pin on the map of the location.
- Scroll all the way down to discover the coordinates.
- Copy the coordinates to your phone’s clipboard by tapping them. If needed, you can also save the set of coordinates to a file on your device’s storage.
- To paste the addresses into another app or to share them with a friend, tap Copy.
How do I get my GPS coordinates?
There are apps available for your phone that can show you your GPS coordinates. This can be useful if you need someone to know where you are, such as in an emergency situation.
What are coordinates on a map?
Coordinates are a group of numbers or numbers and letters that indicate a location on a map. They can assist you in locating a specific location or object.
What is map and map reading?
The technique of looking at a map to discern what is portrayed and how the mapper depicted it is known as map reading. This includes specifying the features or phenomena depicted, the symbols and labels used, and map information that may or may not be displayed on the map.
What is the difference between 4 and 6 figure grid references?
A four-figure grid reference, such as ’19 45,’ denotes a 1 km by 1 km square on a map; and A six-digit grid reference, such as ‘192 454’, represents a 100 m by 100 m square on the map.
How are coordinates used?
System of coordinates, A configuration of reference lines or curves used to indicate the location of points in space.
Points are identified by their distance along a horizontal (x) and vertical (y) axis from a reference point known as the origin (0, 0). Cartesian coordinates can also be used to represent three (or more) dimensions.
What is a 6-figure grid reference accurate to?
What is the precision of a six-figure grid reference? A six-figure grid reference will cover an area of 100m by 100m, or 10,000 square meters, which is larger than Wembley Stadium.
What is a map grid reference?
Grid references are used to pinpoint a certain square on a map. This is significant because it is a universal way for us to define the location of things on a map.
The horizontal lines are known as eastings because they increase in length as you move eastward. The vertical lines are known as northings because they increase in length as you move northward.
How do I find coordinates for an address?
To begin, go to maps.google.com and enter the address or location of interest. Once it has loaded, simply look in the address bar to see the coordinates, which are embedded inside the URL itself.