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Question 1

In surveying, it is unconditionally stated that:

Answer 1

No observation is exact

Every observation contains error

The true value will never be known

Question 2

The difference between error and mistake

Answer 2

Error is the difference between measurement and true value

Error = measurement - true value

Mistake IS NOT error
Mistakes are caused by the misunderstanding the problem, carelessness, fatigue, miss communication,etc

Question 3

Source of errors

Answer 3

Natural errors, caused by environment, such as variations in wind, temperature, humidity, atmospheric pressure, gravity,etc

Instrumental errors, because any imperfection in construction instrument

Personal errors, limitations of the human senses

Question 4

Types of errors

Answer 4

Systematic errors, because any cause of errors. If system conditions remain constant, error will also remain constant.

Random errors, occur after eliminating mistakes and systematic errors because things beyond the control of the observer, obey the laws of probability in all observations.

Question 5

What is Most Probable Value (MPV) and residual

Answer 5

MPV is mean and calculated in redundant observations (observations excess the minimum needed)

Residuals are identical to errors, but residuals can be calculated.
Residuals is the difference between MPV and Measurement

Residuals = MPV - measurements

Question 6

What is precision and accuracy

Answer 6

Precision, the consistency of a group of observations. High precision means low mistakes and errors

Accuracy, the nearness of the observations to the true value

Question 7

What is theory propagation

Answer 7

The process to determine how random errors of several independent measurements accumulate to produce an overall error