The following notes refer to a traverse run by a tacheometer fitted with an anallactic lens, with constant 100 and staff held vertical. Line, Bearing, Vertical Angle, Staff Intercept -PQ, 30o 24′, + 5o 06′,1.875; QR, 300o 48′, + 3o 48′,1.445; RS, 226o 12′, − 2o 36′, 1.725 respectively. Find the length and bearing of SP.

The following notes refer to a traverse run by a tacheometer fitted with an anallactic lens, with constant 100 and staff held vertical. Line, Bearing, Vertical Angle, Staff Intercept -PQ, 30o 24′, + 5o 06′,1.875; QR, 300o 48′, + 3o 48′,1.445; RS, 226o 12′, − 2o 36′, 1.725 respectively. Find the length and bearing of SP. Correct Answer 191.930 m, 126o 47 ′47′′

Use D = Ks + C, where the constant K is equal to (f /i). It is called multiplying constant of the tacheometer and is generally kept as 100. The constant C is equal to (f + c). It is called an additive constant. From the geometry, D=1/2 x s x cot α/2, where s = the distance between the targets of subtense bar, and α = apex angle subtended by targets at O. As α is small tan α/2 = α/2, D = s/α.