SURV1200 Lecture Notes - Lecture 1: A.C.A.B., Refraction, Sea Level
2 Jun 2018
School
Department
Course
Professor
SURV 1200
Introduction to Surveying
1.Types of errors
Gross error - mistakes
Systematic error- occur in accordance with a deterministic system (equation can define, or
correct distance known error that can be corrected)
Random error-after previous errors are removed variances still repeated. No known functional
relationship.
These types of errors are addressed and analyse by using the probability model
Where
Accuracy is the true centered- Need high accuracy and high precision
Precision is the repeated results -Precision of value is quantified using standard deviations
Propagation of errors
Random Error
Systematic Error
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2.Leveling
Leveling is a process to determine a points elevation, or more correctly, the difference in
elevation between two points.
Differential Leveling. Other methods: changes in atmospheric pressure, water levels in a tube
Height datum
A Datum is a reference point, or a reference surface to which the other measurements are
referred.
For heights Australia uses Mean Sea Level (MSL), known as Australian Height Datum (AHD)
This was measured by 30 tide gauges across AUS.
Optical Leveling - Automatic Level and tripod, staff (Ruler), Staff bubble and change plate
3 Different Types of Optical Levels - Dumpty, Tilting and Automatic
Automatic Level automatically adjust the horizontal axis by using a compensator
BM- Bench Mark will refer to
RL - The reduced Level is the start
Types of Level Runs
Closed Loop Level Run
Check error control, control in
height=0
Closed Level Run
Change in Height= Last BM - First
BM
Open(unclosed) Level
Run
Change is unknown
Two Peg Test- Collimation Error- When the collimation axis is not truly horizontal when the
instrument is level
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Document Summary
Systematic error- occur in accordance with a deterministic system (equation can define, or correct distance known error that can be corrected) Random error-after previous errors are removed variances still repeated. These types of errors are addressed and analyse by using the probability model. Accuracy is the true centered- need high accuracy and high precision. Precision is the repeated results -precision of value is quantified using standard deviations. Leveling is a process to determine a points elevation, or more correctly, the difference in elevation between two points. Other methods: changes in atmospheric pressure, water levels in a tube. A datum is a reference point, or a reference surface to which the other measurements are referred. For heights australia uses mean sea level (msl), known as australian height datum (ahd) This was measured by 30 tide gauges across aus. Optical leveling - automatic level and tripod, staff (ruler), staff bubble and change plate.
