Norwegian cadastral XML file setup

To use Norwegian cadastral tolerance checking in Trimble Access, modify the sample CadastralTolerances ‑ Norway.xml file to meet your requirements.

Download the sample CadastralTolerances ‑ Norway.xml file from the Configuration files page.

The sample XML file uses a combination of the Survey class and Classification to determine the tolerance value that the point must be checked against.

The Classification name defines the type of point being measured or staked. The Survey class name defines the tolerance level required for the location of the point.

Survey class

The sample XML file defines a survey class for each level:

<SurveyClasses>

<Class name="ClassA" id="ClassA" algorithm="NorwayCadaster"/>

</SurveyClasses>

To enable cadastral tolerance checking in the job, you must specify the Survey class for each job. To do this, enter the survey class name (ClassA) in the Notes field in the Job properties screen in Trimble Access. All points within the job will have the same class.

Tolerance values

The sample CadastralTolerances ‑ Norway.xml file defines the tolerance values for each ClassA as a control point:

<Classification name="Control1">

<Tolerances id="ClassA" hzTol="0.050" vtTol="0.100" alpha="0.05" internalReliabilityError="0.1" internalReliabilityWarning="0.1" externalReliabilityError="0.1" externalReliabilityWarning="0.1" reliability3D="false">

<TimeDistance minimumMinutes="45" measurementCount="2" />

<TimeDistance minimumMinutes="15" measurementCount="3" />

</Tolerances>

</Classification>

The covariance calculation is done in 3D, but to provide a 2D value the reliability3D value in the file is set to false.

When checking measurements against the defined tolerances, a statistical analysis is made of the data for:

• Blunder detection (grovfeilsøk)

  Blunder detection controls against large deviations between the two measurements or “blunders” (grovfeilsøk).

  A large deviation/blunder is defined as a deviation that is significantly larger than the random deviation you would expect. A large deviation or blunder can be thought of as a deviation three times the standard deviation.

  Because the blunder detection calculation discovers only large errors, the internal reliability and external reliability values are used to indicate the quality of the measurements when smaller deviations are taken into account.

• Internal reliability (indre pålitelighet)

  The internal reliability (indre pålitelighet) value indicates the presence of smaller errors than can be discovered by blunder detection. These errors are referred to as the “maximum remaining deviation”. The threshold for the internal reliability value is a level of significance of 5% or lower.

• External reliability (ytre pålitelighet)

  The external reliability (ytre pålitelighet) value is a calculation of the maximum point deformation, and indicates how much the maximum remaining deviation could impact the end result.

Checks are also made for suitable times elapsing between re-measurements of the same point.

Feature codes

The sample XML file also defines feature codes so that you can easily specify the classification for cadastral points when staking and measuring in the job. For example, points with a Control classification can have any of the following feature codes:

<Codes>

<Code name="surveyPoint" description="Checked Cadastral" classification="Control1"/>

<Code name="OLD" description="Checked Cadastral" classification="Control1"/>

<Code name="PEG" description="Checked Cadastral" classification="Control1"/>

<Code name="IS" description="Checked Cadastral" classification="Control1"/>

<Code name="IT" description="Checked Cadastral" classification="Control1"/>

<Code name="NAIL" description="Checked Cadastral" classification="Control1"/>

For a job where the Notes field is set to ClassA, if you code a point as “NAIL” the point will have a description of "Checked Cadastral", and a classification of "Control1". This means the point must meet a horizontal tolerance of 50mm, because the CadastralTolerances ‑ Norway.xml file specifies that "Control1" points in "ClassA" jobs must have hzTol="0.050".