Longitudinal and transverse profiles

 Longitudinal and transverse profiles form the basis for the detailed planning and stakeout of communications routes (e.g. roads) and also for the calculation of fill and for the best possible accom. modation of the routes to the topography. First of all the longitudinal axis (road. line) is staked out and stationed; this means that points are established and marked at regular intervals. A longitudinal profile is then created along the roadline, the heights of the station points being deter- mined by line levelling.

 At the station points and at prominent topographic fea- tures, transverse profiles (at right-angles to the roadline) are then recorded. the ground heights for the points in the determined with the aid of the known 14 instrument height. First, po-sition the staff at a known station point ; the instru- ment of the comprises the sum of the staff reading and the station point height. Now subtract the staff readings (at the points on the transverse profile) from the instrument height; this gives the heights of the points involved.

 the distances from the station point to the station point to the various points in the transvers points in the transverse profiles are determined either with the surveyor's tape or optically using the level. when representing a longitudinal profile graphi- cally, the heights of the station points are expressed at a much bigger acale (e.g 10× greater) than that of the stationing of the longi- tudinal direction, which is related to a round reference height (illustration above).