Control of Rounds¶

You can choose between two control methods:

Statistical test
Maximum spread between full rounds

When reducing rounds, key values for the control of rounds are also calculated, depending on the selected control method.

Statistical Test¶

It is up to the surveyor to decide how much error is acceptable for the type of survey being performed. Statistics can only identify which observations should be investigated as possible errors.

After reduction of rounds (averaging and reduction), key values are calculated to assist in the control of the rounds.

When averaging, all relevant observations have a relative weight of 1.0. Directions, vertical angles, and distances are considered separately. The standard deviation of the measurement data is calculated after averaging.

The Original list will include a column for the difference between the averaged and observed value, and a column for the control value (maximum allowed difference).

Column	Description
...	...
Hor. direction	Measured direction.
Mean diff. dir.	Mean value minus measured value. Difference between mean value and measured value.
Control value dir.	Control value for direction calculated from the normal distribution.
...	...

At the end of the list Before Calculation, you will find columns for the calculated standard deviation from the measurement data.

Column	Description
Std. mean diff. dir.	Standard deviation for direction calculated from round measurements.
Std. mean diff. v.a.	Standard deviation for vertical angle calculated from round measurements.
Std. mean diff. dist.	Standard deviation for distance calculated from round measurements.

When calculating control values, we assume normally distributed observations and that the approved ones fall within the specified confidence interval.

Example

95% confidence interval, 2.5% on each side.

A 95% confidence interval gives a factor, and +/- 1.96 * std. on the observation is then the threshold value.

Maximum Spread Between Full Rounds¶

With this method, requirements (empirical values) are set for the maximum deviation between full rounds. The maximum deviation is calculated and displayed as follows:

Calculate values for all observation types (direction, vertical angle, and distance) for each full round (average of instrument positions I and II).
Calculate the maximum deviation between the full rounds for all observation types.
Check the calculated maximum deviation against the entered tolerance values.
Mark those exceeding the allowed value in red in the lists.

At the end of the Before Calculation list for observations (conventional), you will find columns for the maximum spread for all observation types.

Column	Description
Spread dir.	Spread for direction between full rounds
Spread v.a.	Spread for vertical angle between full rounds
Spread dist.	Spread for distance between full rounds

At the end of the Before Calculation list for stations (conventional), you will find columns for the maximum spread for observation types and which stations (min./max.) provide these values.

Column	Description
Dir. max. spread	Maximum spread for direction between full rounds.
Min. station	The station is also marked in yellow in the Original lists for stations and observations.
Max. station	The station is also marked in yellow in the Original lists for stations and observations.
V.a. max. spread	Maximum spread for vertical angle between full rounds.
Min. station	The station is also marked in yellow in the Original lists for stations and observations.
Max. station	The station is also marked in yellow in the Original lists for stations and observations.
Dist. max. spread	Maximum spread for distance between full rounds.
Min. station	The station is also marked in yellow in the Original lists for stations and observations.
Max. station	The station is also marked in yellow in the Original lists for stations and observations.

Report¶

There is a dedicated report for documenting the control of rounds.