Cadastral Horizontal Control Network

The CHN provides the street-level control marks that are used by surveyors to connect to and orient cadastral surveys in terms of the official geodetic datum (NZGD2000).

The following page summarises the main characteristics of the network.

Purpose

To provide marks to enable cadastral surveyors to efficiently connect to, and orient in terms of, the official geodetic datum

Density

  • Across North Island, South Island, Stewart Island/Rakiura
  • Sufficient to ensure that 98%* of submitted cadastral survey datasets include a witness or permanent reference mark with order 6 or better

Accuracy

  • Order: 5 (horizontal only)
  • Tier: C (0.15 m)
  • Class: VIII (0.01 m, 5x10-5m/m)
  • Class evaluation radius: 0.3 km (urban), 1 km (rural)

Mark characteristics

  • Campaign GNSS
  • Conventional observations

Location

  • Sited so that surveyors can easily and safely locate and occupy
  • Suitable for collecting GNSS observations

Mark access 

  • Physical access to marks to collect GNSS observations
  • Visible from afar to enable conventional observations

 

* This is a progressive target that will be achieved by 1 January 2013. In the interim the compliance levels are: 89% 1 January 2010, 92% 1 January 2011, 95% 1 January 2012.