Q$.7$ In order to reduce errors in the measurement of a vertical angle, a set of measurements are taken and it is found that the

average angle of $9{02}^{\text{'}}{05}^{\text{'}\text{'}}$ forms a height of instrument of $1\mathrm{.}565$ m to a target height of $2\mathrm{.}165$ m $.$ If the elevation of the

instrument station is $189\mathrm{.}250$ m above the mean sea level, find the elevation of the staff station. Assume any data, if

required. Assume that the tacheometric observation is fitted with an anallactic lens and has a fixed target of height $1$ m $.$

Ans

$x1\mathrm{.}50\mathrm{.}2m$

$x2\mathrm{.}304\mathrm{.}14m$

$204\mathrm{.}134$ m

$x4\mathrm{.}102\mathrm{.}06m$