Eastings and northings are part of a Cartesian coordinate system, called the National Grid, used in the United Kingdom for surveying and logistics. The grid's origin is an arbitrary point in the Celtic Sea, and the units are metric. Surveyors use this coordinate system to input spot elevations and surface features. Autodesk AutoCAD, a computer aided design (CAD) application, allows surveyors to precisely record the survey data onto a computer-drawing file. To enter northings and eastings, you must establish the origin and change your drawing units in AutoCAD.
Open Autodesk AutoCAD. Type "Units" into the command line. Change the "Insertion Scale Units" to "Millimeters" and the "Length Type" to "Decimal." Change the "Angle Type" to "Surveyor's Units." Press "OK."
Establish the origin by typing "Point" into the command line and typing "0,0" to create a point at the origin. This point is equivalent to the "False Origin of the National Grid" established by the Ordnance Survey of the United Kingdom.
Determine the location of a benchmark or landmark near your survey. Because you are using the National Grid coordinate system, the coordinate will be provided as an even number of letters and an even number of numbers, such as the Tower of London: "TQ 336805."
Divide the number into Eastings and Northings. The Tower of London is "TQ 336805," which is equivalent to "E5336" and "N1805." In this case, the units for the coordinates are 100 meters. If you do not know how to read and interpret the coordinates of the National Grid, consult the Ordnance Survey's website.
Convert the coordinates to millimetres. "E5336" stands for 533,600 meters east of the origin, whereas "N1805" stands for 180,500 meters north of the origin. Multiply the two numbers in meters by 1000 to convert the numbers to millimetres. Therefore, the "E5336" is 533,600,000 millimetres east of the origin, while "N1805" is 180,500,000 millimetres north of the origin.
Place the benchmark or landmark on the AutoCAD drawing. Type "Point" into the command line. Type "x,y," where "x" is the Easting (or distance East of the origin) and "y" is the Northing (or distance North of the origin.) For example, type "533600000,180500000," after typing "Point" into the command line to place the Tower of London example into the drawing.
Type "Z" followed by "A" to zoom to see all parts of the drawing. Your benchmark or landmark should appear to the right and above the origin.
Place points relative to the benchmark by typing "@x,y," where "@" describes a location "x" millimetres horizontally and "y" millimetres vertically relative to another. Alternatively, you can insert points by typing '@d<N00d00'00E,"' where "@" describes a location "d" millimetres distant at an angle of 0 degrees 0 minutes 0 seconds East of North.
Things you need
- Ordinance Survey map