What is metrix Chain, Chain Surveying, Chain Introduction in chain survey

As far as possible the triangles should have angles close to 60°, in no case less than 30°. * Offsets taken may be perpendicular or oblique. * Perpendicular offsets may be set by swinging, using cross staffs, optical square or prism square. * Fieldwork consists of: 1. Reconnaissance survey to select stations and prepare typical key plan. 2. Drawing reference sketches 3. Line by line surveying * Office work consists in plotting * Obstacles to chaining may be grouped as 1. Obstacles to ranging 2. Obstacles to chaining 3. Obstacles to both chaining and ranging By making suitable alternate measurements, the obstructed length may be calculated. Angle and Direction Measurements The direction of a survey line may be defined as the horizontal angle between the line and a reference line. The reference line is known as meridian and the angle as bearing. * A compass measures bearing of a line w.r.t. magnetic north-south direction whereas it is possible to measure an angle between any two lines us...