Concept: Latitude: It is the projection of a line onto the North-South axis. Departure: It is the projection of a line onto the east-west axis. For any segment AB of length L and θ with North,
Latitude = L cosθ & Departure = L sinθ Sign convention: The latitude of a line is the orthographic projection on the N-S meridian. It is positive in the case of Northing and negative in the case of Southing. The departure of a line is the orthographic projection on the E-W meridian. It is positive in the case of Easting and negative in the case of Westing. Hence, If the latitude and departure of a survey line are negative, then the direction of mentionedlines in the whole circle bearing system Will be in the range of 180° to 270°.