$$\alpha $$ and $$\beta $$ are the angles subtended by a point of elevation h at their air station with respective plumb points. Photo scale and focal length of the lens being ‘S’ and ‘f’ respectively. Parallax displacement of the point due to relief, is
A. $$\frac{{{\text{h}}\tan \alpha }}{{\text{S}}}$$
B. $$\frac{{{\text{h}}\tan \beta }}{{\text{S}}}$$
C. $$\frac{{{\text{h}}\left( {\tan \alpha + \tan \beta } \right)}}{{\text{S}}}$$
D. $$\frac{{{\text{h}}\left( {\tan \alpha - \tan \beta } \right)}}{{\text{S}}}$$
Answer: Option C
Related Questions on Surveying
Which of the following methods of contouring is most suitable for a hilly terrain?
A. Direct method
B. Square method
C. Cross-sections method
D. Tachometric method
A. 750 mm × 900 mm
B. 600 mm × 750 mm
C. 450 mm × 600 mm
D. 300 mm × 450 mm
A. 22° 30'
B. 23° 27'
C. 23° 30'
D. 24° 0'
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