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Another way of identifying the same point P is. y. u. +P (. r , . ). r. u. x. This is known as a . POLAR . Coordinate System. FOR SURVEYING we use a slightly different form of notation . instead of . x,y we use E,N (. Easting, . Northing). N. +P (. E ,N). u. D. E. N.B.
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Another way of identifying the same point P is y u +P ( r , ) r u x This is known as a POLAR Coordinate System.
FOR SURVEYING we use a slightly different form of notation ... instead of x,y we use E,N ( Easting, Northing) N +P ( E ,N) u • D E
N.B. Easting is always quoted first and then Northing . u is always measured in a CLOCKWISE direction from North. u is known as the WHOLE CIRCLE BEARING. (WCB) We MUST be able to Convert from Rectangular to Polar VERY QUICKLY. (and from Polar to Rectangular)
N N Q u u PQ QP P We consider that the line PQ is a different line to line QP Any line has two bearings
Given the co-ordinates of two points, calculate the distance between them and the Q N bearing of the line joining them. u P PQ The order of the points is very important: We begin at P and move to Q P is the NEAR POINT, with co-ordinates NearE, NearN And Q is the FAR POINT, with co-ordinates FarE, FarN For line PQ
1. Difference in Northings: FarN - NearN 2. Difference in Eastings: FarE - NearE Your calculator gives two answers :- 1. Distance P to Q (in metres) 2. Bearing P to Q (if this is negative, add 360o) (Depending on your calculator, you may have to convert the bearing to degrees, minutes and seconds)