SURV Flashcards
(19 cards)
0° - 90° is in what direction?
NE
90° - 180° is in what direction?
SE
180° - 270° is in what direction?
SW
270° - 360° is in what direction?
NW
NW : bearing to azimuth formula
azimuth = 360° - bearing
SW : bearing to azimuth formula
azimuth = bearing - 180°
NE : bearing to azimuth formula
Bearing = Azimuth
SE : bearing to azimuth formula
azimuth = 180° - bearing
COMPASS RULES: correction to be applied in latitude formula
Cl = ∑lat (d/∑D)
COMPASS RULE: correction to be applied in departure formula
Cd = ∑dep (d/∑D)
How to get the correction angle?
[(n-2)180°]/sum of sides
NE : azimuth to bearing formula
Azimuth = Bearing
NW : azimuth to bearing formula
bearing = 360° - Azimuth
SW : azimuth to bearing formula
bearing = 180° + Azimuth
SE : azimuth to bearing formula
bearing = 180° - azimuth
TRANSIT RULE: formula for correction latitude
Cl = lat (∑lat)/∑NL + ∑SL
TRANSIT RULE: formula for correction departure
Cd = dep (∑dep)/∑Ed + ∑Wd
formula for adjusted length
L’ = √(lat’)² + (dep’)²
where:
- lat’ = adjusted latitude
- dep’ = adjusted departure
formula for adjusted direction
α = tan^-1[(dep’)/(lat’)]
