23873 version 1

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Confirm the reliability of existing land survey marks

Level / 6
Credits / 12

PurposeThis unit standard is for people working, or who intend to work, in the surveying profession as a survey technician in a land surveying context.

People credited with this unit standard are able to: analyse existing documents for survey data; locate existing survey marks using a variety of methods; and explain surveying measurement terminology and assess the reliability of existing survey marks.

Subfield / Surveying
Domain / Survey Practice
Status / Registered
Status date / 25 February2008
Date version published / 25 February2008
Planned review date / 31 December 2012
Entry information / Open.
Accreditation / Evaluation of documentation and visit by NZQA and industry.
Standard setting body (SSB) / Infrastructure ITO
Accreditation and Moderation Action Plan (AMAP) reference / 0101

This AMAP can be accessed at

Special notes

1The following legislation and documentation must be complied with:

Cadastral Survey Act 2002;

Surveyor-General’s Rules for Cadastral Survey 2002/2,Surveyor-General’s Rulings and Advisory Notes, andGeodetic specifications and forms published by LandInformation New Zealand at

job specifications;

service utility records;

survey plans.

2Terminology may be referenced from the New Zealand Institute of Surveyors website, when available, or from the recommended reference, Definitions of Surveying and Associated Terms 2005, American Congress on Surveying and Mapping, available at

3Definition

GPSrefers to the United States NAVSTARGPS or Navigation Signal Timing and Ranging Global Positioning System.

Elements and performance criteria

Element 1

Analyse existing documents for survey data.

Rangeexisting documents may include– survey plans, titles, service utility records, local authority records, cadastral data set, workplace records;

surveys may include – cadastral, as-built, topographical, engineering, construction;

evidence is required for five surveys.

Performance criteria

1.1Documents are analysed for a possible origin in accordance with job specifications.

1.2Analysis of documents determines the presence of physical features that will impact on the job.

Rangeimpacts may include but are not limited to – traffic, topography, obstructions, services.

1.3Data from documents are analysed for level datum in accordance with job specifications.

1.4Data from documents are analysed for connection to the survey in accordance with job specifications.

Element 2

Locate existing survey marks using a variety of methods.

Performance criteria

2.1Methods selected for locating existing survey marks ensure that the marks are found.

Rangemethod – offsets from a physical object, traverse, resection, intersection, free station;

may include – GPS.

2.2Existing survey marks are located in accordance with survey data.

Rangemarks – boundary peg, iron tube, iron spike, survey standard, lead plug, aluminium mark, trig station.

Element 3

Explain surveying measurement terminology and assess the reliability of existing survey marks.

3.1Basic concepts in correct surveying measurement are explained in accordance with surveying terminology.

Rangemeasurement theory, measurement practice;

terminology – accuracy, precision, tolerance, misclosure, reliability, error;

error types – random, systematic, gross.

3.2The accuracy of methods and equipment used to measure distance and angles for surveying is explained in accordance with the capability of total station surveying instruments.

Rangethree methods.

3.3The reliability of existing survey marks is explained in terms of practical limits on the accuracy of surveying in the field, and subsequent adjustments.

Rangeaccuracy of – observations, measurements, adjustments applied to account for misclosures;

accuracy of misclosures to Class 1 cadastral survey requirements;

adjustments – bowditch or least squares.

3.4Factors affecting the reliability of survey marks are explained in accordance with the Surveyor General’s Rulings and Advisory Notes.

Rangefactors – stability, ground conditions, physical features.

3.5Reliability of existing survey marks is assessed by re-observing previous survey observations in accordance with position requirements for Class 1 cadastral surveys and level requirements for third order geodetic specifications.

Rangeat least three survey marks.

3.6Reliability of existing survey marks is assessed by new observations and calculations in accordance with position requirements for Class 1 cadastral surveys and level requirements for third order geodetic specifications.

Rangeat least three survey marks.

Please note

Providers must be accredited by NZQA, or an inter-institutional body with delegated authority for quality assurance, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment.

Industry Training Organisations must be accredited by NZQA before they can register credits from assessment against unit standards.

Accredited providers and Industry Training Organisations assessing against unit standards must engage with the moderation system that applies to those standards.

Accreditation requirements and an outline of the moderation system that applies to this standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The AMAP also includes useful information about special requirements for organisations wishing to develop education and training programmes, such as minimum qualifications for tutors and assessors, and special resource requirements.

Comments on this unit standard

Please contact Infrastructure you wish to suggest changes to the content of this unit standard.

 New Zealand Qualifications Authority 2018