DETERMINATION OF HEIGHT USING TAPE AND RANGING POLES

There are conditions to determine the height of features like radio tower, telecommunication mast, storey buildings e.t.c, the major condition is that the terrain must be fairly leveled and the base of fhe tower is accessible. 

EQUIPMENT NEEDED
1. Tape(Steel band, Linen e.t.c)
2. Ranging poles
3. Booker
4. Writing material
5. Calculator

Sketch of Illustration below

METHODOLOGY

>>Measure distance of fixed point from Tower base(A) to Ranging pole at point (B) i.e measure line |AB|.

>>Select a convenient point on Ranging pole at B and mark out B'.

>>Instruct the Survey assistant to move the second ranging  pole to fix point A' in between line |AB| till imaginary line from |EB'| can be view through point E'
>> Measure line |CA| and |C'B'|.

COMPUTATION
Applying similar triangle method
 |C'B'| / |CB'|= |C'E'| / |CE|
make |CE| the subject of the formula
 |CE|=( |CB'|* |C'E'| )/ |C'B'|
|AE|= |CA| + |CE|
|AE|= |CA| + ( |CB'|* |C'E'| )/ |C'B'|
Taking L.C.M
|AE|= (( |C'B'| * |CA| )+ ( |CB'|* |C'E'| ) )/ |C'B'|