In tacheometric surveying, the horizontal distance from instrument to staff using the anallactic lens (K=100, C=0) is:
Choose the correct answer
H = 50s
H = 100s·cos²θ (s = staff intercept, θ = vertical angle from horizontal)
H = 100s/sinθ
H = s/100
Correct Answer
B. H = 100s·cos²θ (s = staff intercept, θ = vertical angle from horizontal)
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Tacheometric formula: H = Ks·cos²θ + C·cosθ where K = multiplying constant (100), C = additive constant (0 for anallactic lens), s = staff intercept, θ = vertical angle. For horizontal staff and horizontal sight (θ=0): H = Ks = 100s. For inclined sight: H = 100s·cos²θ. Anallactic lens eliminates additive constant C.
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