Using SCIMS Online

The mark type is one of the following:

The Mark Type is followed by a number in the range of 1 to 99999999. This may or may not be followed by a witness/eccentric mark number in the range of 1 to 9.

Mark Numbers above 87,200 are not duplicated.

Cadastral Reference Marks (CRs) are only in the range from 500,000 to 599,999.

Cadastral Reference Marks (CRs) are recorded in SCIMS using a coordinate of known Class and a height of known Class. 

CRs do not have a Locality Sketch Plan to help surveyors to find the mark. The Deposited Plan or Crown Survey Plan will be needed to assist in the location of the mark.

Name

In addition to the Trig Station mark type and number, a name is also used for all Trig Stations. If [P] appears at the end of the description, the station is monumented with a concrete or steel pillar.

Alias

An Alias is used for cross-reference to mark identifiers issued by other organisations. Most Miscellaneous Marks will have an Alias recorded, usually referencing the identifier supplied by the organisation that originally placed the mark (for example, MM 5807 at Uralla has an Alias “MR9/6301”).

SCIMS Status Code: (D)

Physical evidence of the removal of a survey mark, or after examination of all information it is evident that a mark has been moved from its original position. 

This new position constitutes a new mark requiring re-numbering of the mark.

SCIMS Status Code: (F)

Survey mark found undamaged and in its original position.

SCIMS Status Code: (N)

Survey mark not found after an extensive search, using all information available but no physical evidence of the removal of the survey mark.

SCIMS Status Code: (R)

Mark is in a restricted area and requires special permission for occupation. Use the 'Comments' or 'Access Details' found in the SCIMS Report for more information.

SCIMS Status Code: (S)

Mark is located in an area identified as being subject to movement.

SCIMS Status Code: (U)

Mark was found, however it was in an unstable condition or there was evidence that it had been disturbed or moved. Status will remain “uncertain” until verified by survey.

SP1 (v1.7) defines Class as:

Class is a function of the planned and achieved precision of a survey network and is dependent upon the following components:

• the network design;
• the survey practices adopted;
• the equipment and instruments used; and
• the reduction techniques employed,

all of which are usually proven by the results of a successful, minimally constrained least squares network adjustment computed on the ellipsoid associated with the datum on which the observations were acquired.

The following table refers to Class codes as they apply to coordinates in the SCIMS database and should not be used for any other purpose.

More information: Standards and Practices for Control Surveys (SP1) Version 1.7 (PDF 962.2KB).

Order is only shown for GDA94 coordinates. SP1 (v1.7) defines Order as:

Order is a function of the Class of a survey, the conformity of the new survey data with an existing network coordinate set AND the precision of any transformation process required to convert results from one datum to another.

Stations in horizontal control surveys are assigned an Order commensurate with the Class of the survey and the conformity of the survey data with the existing coordinate set.

The Order assigned to the stations in a new survey network following constraint of that network to the existing coordinate set may be:

a) not higher than the Order of existing stations constraining that network; and

b) not higher than the Class assigned to that survey.

Order is only shown for PSMs with coordinates in the GDA94 datum, this includes Order for heights in AHD71 (i.e. Ellipsoidal Heights in GDA2020 will show PU and LU).

More information: Standards and Practices for Control Surveys (SP1) Version 1.7.

Positional Uncertainty (PU) and Local Uncertainty (LU) replace Order for coordinate accuracy information in GDA2020. SP1 (v1.7) defines PU as:

the uncertainty of the coordinates or height of a point, in metres, at the 95% confidence level, with respect to the defined reference frame.

To make interpreting the values published for PU, SCIMS applies the following rules:

• PU or LU values < 1 metre: Round up to the nearest centimetre (i.e. 0.01)
• PU or LU values ≥ 1 metre and < 10 metres: Round up to the nearest decimetre (i.e. 1.1)
• PU or LU values ≥ 10 metres: Round up to the nearest metre (i.e. 10).

Local Uncertainty (LU) is defined in SP1 v1.7 as:

the average measure, in metres at the 95% confidence level, of the relative uncertainty of the coordinates, or height, of a point(s), with respect to the survey connections to adjacent points in the defined frame.

LU provides a general indication of how accurate a mark is with respect to the surrounding connected marks.

The same rules for rounding as applicable to PU have been applied to LU.

It is accepted that some heighting techniques, such as differential levelling, propagate errors in proportion to the square root of the distance. 

Other techniques, such as GNSS and trigonometric levelling, propagate errors mainly in proportion to the distance. This is particularly apparent on distances greater than one kilometre.

Therefore different types of Class and Order are assigned according to the heighting technique used. Refer to SP1 (v1.7) for details of observation techniques.

The following table refers to Class codes as they apply to heights in the SCIMS database and should not be used for any other purpose.

Note: 'd' in the table above refers to distance in kilometres

As per horizontal coordinate accuracies, Order for heights is only shown for those marks whose horizontal datum is in GDA94. For marks where the horizontal datum is GDA2020, PU and LU replace Order. This applies to marks with Ellipsoidal Heights as well.