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3 types of coordinates

The challenge is a series of 40 locations around Hatch Warren and the surrounding area. The location of each is shown using one of three different methods of references

  • OS Grid Reference
  • what3words
  • Latitude & Longitude

Below are explanations of each of these systems to help you locate our markers and take part.

OS Grid Reference

You might have noticed by now that OS maps are covered in a series of blue grid lines. These grid lines help you to pinpoint an exact location anywhere on the map. The vertical lines are called ‘eastings’, as they increase in value as you travel east on the map. The horizontal lines are called ‘northings’ as they increase in value as you travel north on the map.

These are linked to the National Grid which provides a unique reference system, and can be applied to all OS maps of Great Britain, at all scales.

The OS Grid References we have used are 6-figure references to give a more precise location.

A - National

Great Britain is covered by grid squares measuring 100 kilometres across and each grid square is identified by two letters, as shown in diagram A.

B - Region

On OS maps, these squares are further divided into smaller squares by grid lines representing 10 kilometre spacing, each numbered from 0 to 9 from the south west corner, in an easterly (left to right) and northerly (upwards) direction. You can see this in diagram B.

Using this system you can identify a 10 kilometre grid square. For example, the above image shows TL63. After the letters you can quote the eastings (6) first, then the northings (3).

C - Local

On an OS Landranger map you can find the two main grid letters (in this case TL) on the legend or the corner squares of the map. The grid is further divided into 1 kilometre intervals, as shown in diagram C.

D - 4 figure

It is easy to find a particular place using a grid reference. To start, a four-figure grid reference is a handy way of identifying any square on a map. Grid references are easy if you can remember that you always have to go along the corridor before you go up the stairs. To find the number of a square first use the eastings to go along the corridor until you come to the bottom left-hand corner of the square you want.

Write this two-figure number down. Then use the northing to go up the stairs until you find the same corner. Put this two‑figure number after your first one and you now have the four-figure grid reference, which looks like the example in diagram D: 6233.

E - 6 figure

If you want to pinpoint an more exact place on a map, such as your own house, you will need to use a six-figure grid reference. First find the four-figure grid reference for the square and write it down with a space after each set of numbers, like this: 62_ 33_

Now imagine this square is divided up into 100 tiny squares with 10 squares along each side. Still remembering to go along the corridor and up the stairs, work out the extra numbers you need and put them into your four-figure grid reference like this in diagram E: 625 333.

A note on accuracy

6-figure OS Grid References give you the location accurate to 100m2. This is fine when you are in an area with obvious features (such as a junction of footpaths next to a field) however in Urban settings they can cause problems.

Therefore all Grid References provided are 10-figure references. Following the same the method as shown above for the difference from 4-figure to 6-figure, you can further narrow down the location of the marker by using the remaining digits in the reference.

To aid navigation/accuracy, we have given a short description/comment on all OS Grid locations to help you locate the markers.

Use an OS Map

The best way to use an OS Grid Ref is to plot it onto an OS map using the method above.

All locations in this challenge are on both of these OS Maps:

  • 1:25,000 OS Explorer 144
    Basingstoke, Alton & Whitchurch
  • 1:50,000 OS Landranger 185
    Winchester & Basingstoke

Which map you choose is up to you but we would recommend the 1:25,000 Explorer map as it offers more detail to aid your navigation.

 

Use an app

You can use the free OS Maps website or app to see where a marker is. Enter the grid reference to the search box to see it’s location on their free maps.

If you have a subscription to OS Maps you will be able to view the location on their Explorer or Landranger scale Leisure maps.

Using the App will also allow you to follow a compass right to the location of the marker.

Transfer to another map

The website “UK Grid Reference Finder” allows you to convert between many location types.

Copy the Grid Reference from the list and click the button to visit UK Grid Reference Finder. Once on the website, paste it into the Grid Reference box and press Go.

The map will show you your selected location along with various alternative coordinate types including, at the top, Latitude & Longitude.

Links to various maps including Ordnance Survey and Google Maps are also available.

What 3 Words

what3words is a really simple way to talk about location. It is a map system that divides the whole planet into a grid of 3x3m squares.

Each 3m square in the world has a unique 3 word address that will never change.

People can use what3words to find their tents at festivals, navigate to B&Bs, and to direct emergency services to the right place.

what3word locations can be identified easily due to their format: ///tributes.plotting.secrets

To find a what3words locations you have two options:

Use the app/website

On either the app or website, simply enter the 3 word address in the format ‘word.word.word’ into the search bar (remember to add in the full stops).

On the app you can then select the correct 3 word address and tap ‘Navigate here’. Next, select your favourite navigation app to go straight there. “Compass” mode will point you in the direction once you get close.

Transfer to another map

If you want to use the what3words location on another map you will need to convert the words to coordinates.

The website “UK Grid Reference Finder” allows you to convert between many location types.

Copy the three word address and goto UK Grid Reference Finder. Once on the website, paste it into the what3words box and press Go.

The map will show you your selected location along with various alternative coordinate types including, at the top, Latitude & Longitude.

Links to various maps including Ordnance Survey and Google Maps are also available.

Latitude & Longitude

Latitude and Longitude (Lat/Long) are a coordinate system that covers the whole planet. In general they give you the location in terms of Degrees from both the Equator (North & South) and Greenwich Meridian (East & West).

There are many variations of how Lat/Long are displayed but we have used ‘Decimal Degrees’ which will like this for Hatch Warren Community Centre: 51.233516 -1.134666.

51.233516 is the Northing and shows how far North (positive number) or South (negative number) of the Equator you are.

-1.134666 is the Easting and shows how far East (positive number) or West (negative number) of the Greenwich Meridian you are.

Use an app or website

There is a wide range of mobile apps that can show you a location by entering Lat/Long coordinates. Both Bing Maps and Google Maps accept the lat/long in the search box with a comma separating the two numbers (51.233516,-1.134666).

Which website you use is personal choice. Bing has the option to view OS Mapping which can be useful.

Transfer to another map​

The website “UK Grid Reference Finder” allows you to convert between many location types.

You will need to copy & paste each of the Northing and Easting numbers into the UK Grid Reference Finder website where Lat and Long are in separate boxes.

The map will show you your selected location along with various alternative coordinate types including, at the top, Latitude & Longitude.

Links to various maps including Ordnance Survey and Google Maps are also available.