Angles and Directions
the direction of the line passing through the astronomic north and south poles and the observer’s position. Used for all surveys of large extent.
Astronomic Meridian
an imaginary surface of the sea which is midway between high and low tides. It is taken as reference surface to which most ground elevations are referred
Mean Sea Level
In three-wire leveling, the 'mean' or 'average' reading used for the elevation calculation is derived from which wires?
The upper, middle, and lower wire readings
The Compass Rule (Bowditch Rule) is based on the assumption that errors in measurement are ________.
A) Proportional to the square root of the distance.
B) Directly proportional to the length of the course.
C) Inversely proportional to the length of the course.
D) Constant regardless of the distance.
B) Directly proportional to the length of the course.
In a closed traverse, the sum of latitudes of known sides is +120.45 m and the sum of departures is -88.30 m. What is the latitude of the missing closing side?
-120.45 m
Draw the bearing N 30 E
Drawing in the board
a curve line which graphically portrays the intersection a vertical plane with the surface of the earth. It depicts ground elevations of selected critical points along a surveyed line and the horizontal distance between these points
Profile
A surveyor records the following backsite readings: Upper = 1.854 m, Middle = 1.720 m, and Lower = 1.587 m. What is the value of the 'Mean' reading for this setup?
1.720 m
CONGRATULATIONS
A missing traverse side has a latitude of -60.00 m and a departure of +80.00 m. What is the length of this side?
100.00 m
The clockwise angle from the north or south end of the reference meridian to the line in question.
Azimuth
During profile leveling, any point that is NOT a Turning Point (TP) or a Benchmark (BM) but is read to determine ground elevation is called an ________ Foresight (IFS)
Intermediate
BONUS
CONGRATULATIONS!
In the Compass Rule, the correction to the Latitude of a side is calculated as:
A) (Total Error in Latitude) × (Latitude of that side / Total Latitude)
B) (Total Error in Latitude) × (Length of that side / Perimeter of Traverse)
C) (Total Error in Departure) × (Length of that side / Perimeter of Traverse)
D) (Total Error in Latitude) / (Number of Sides)
B) (Total Error in Latitude) × (Length of that side / Perimeter of Traverse)
A closed traverse has five sides. For the first four sides, the sum of latitudes is +45.20 m and the sum of departures is -32.10 m. What are the Latitude and Departure of the fifth (omitted) side?
Latitude: __________ m
Departure: __________ m
Latitude: +45.20 m
Departure: -32.10m
A closed traverse has the following azimuths:
Draw the traverse and label all directions.
Drawing in the board
A backsight (BS) of 1.45 m is taken on a Benchmark (BM) with an elevation of 100.00 m. What is the Height of Instrument (HI)?
101.45 m
If the Elevation of BM1 is 50.000 m and the Mean Backsight from three wires is 1.250 m, the Height of Instrument (HI) is __________ m.
51.250 m
A closed traverse has a total perimeter of 800 m. The total error of closure in Latitude is +0.12 m. Using the Compass Rule, what is the correction for a side that is 150 m long?
-0.0225
Calculation: Correction = -(0.12) x (150/800) = -0.0225.
BONUS
CONGRATULATIONS
A line has a bearing of S 88 20' W. What is its azimuth from North?
268 20'
The elevation of a point is calculated by subtracting the __________ from the Height of Instrument (HI)
Foresight (FS) or Intermediate Foresight (IFS)
A foresight (FS) of 2.50 m is taken on TP2 from an HI of 310.00 m. The elevation of TP2 is __________ m.
307.50 m
A traverse side has a Latitude of 120.00 m and a Departure of 80.00 m. The sum of the absolute values of all Latitudes in the traverse is 600.00 m. If the total closure error in Latitude is -0.10 m, what is the correction for this side using the Transit Rule?
+0.02 m
Calculation = -(-0.10) x (120/600) = +0.02
In a traverse where the bearing of side BC and the length of side CD are omitted, a common technique is to draw a 'closing line' between which two points?
Between points B and D