Obstacles in Recording Details:

When the outline of the object representing important ground feature changes frequently, it is difficult to measure and plot the details of the object. If the object is straight, it is just essential to measure offset distances at two ends and draw a straight line among the ends. If therefore the object is having irregular boundaries as display in Figures (a) and (b), it is essential to set offset at much less intervals, particularly at points where the object boundary changes direction.

Figure (a): Object with Curved Boundary

Figure (b) : Curved Road/Railways or Nallah