If the staff reading at the instant of observation is equal

If the staff reading at the instant of observation is equal to 2.81 m and the measurement obtained by the sounding line was 5.88 m, determine the elevation of the station under consideration if the elevation on which the staff is planted (point at which staff reading is zero) is equal to 65.73 m amsl A hydrographic survey was conducted using the \"range line and an angle from shore\" method First, a baseline was established with four range poles marking the four range lines along which the boat crew will get soundings. The range poles are 5 m apart. Second, the transit was placed 5 m away from the leftmost range pole (range line 1) and its elevation was known to be 0.5 m amsl. Finally, a graduated staff was placed on water such th if it is sighted from the transit, the MWR will be exactly 1 m (HI = 0.3 m). Complete the table below. |-| Horizontal Angle | | | 5 deg min sec m m m 1 84 36 38 2 77 59 19 3 74 44 42 0 4 69 19 32 3.000 0.200 3.311 0.410 3.888 0.002 2.901 0.201

Solution

Elevation of staff station = 65.73 m

Staff reading = 2.81 m

So line of sight = 65.73 + 2.81 = 68.54 m

Station Elevation = Line of Sigh -Sounding depth = 68.54-5.88 = 62.66 m