It is intended to form a minimum coverage of control marks across New Zealand, its offshore islands and the Ross Sea Region. In most cases the BGN requirements will be met by marks from other control networks. Major uses of this network are to support the registration of aerial and space-based imagery and to enable the consistent mapping of features and objects. The following page summarises the main characteristics of the network.
Purpose
To provide marks to enable non-cadastral survey users to connect their datasets to official geodetic and vertical datums
Density
Mainland New Zealand and offshore islands
- 50 km of one BGN mark
- 100 km of three BGN marks
Ross Sea Region where topographic mapping is provided
- 100 km of one BGN mark
- 200 km of three BGN marks
Accuracy
Order: 5
Tier: Horiz C (0.15 m), Vert F (0.35 m)
Class: Horiz VIII (0.01 m, 5x10-5m/m), Vert IX (0.02 m, 1x10-4m/m)
Class evaluation radius: 0.3 km (urban), 1 km (rural)
Mark characteristics
Campaign GNSS
Overhead imagery identification
Location
Sited so that surveyors can easily and safely locate and occupy
Sited for easy identification on overhead imagery
Suitable for collecting GNSS observations
Mark access
Physical access to marks to collect GNSS observations
Visible from afar to enable overhead imagery identification (New Zealand and offshore islands only)