About PositioNZ

This page explains PositioNZ and how to access data.

The New Zealand Active Control Network (PositioNZ) consists of 31 continuously tracking Global Positioning System (GPS) stations at locations across New Zealand, two in the Chatham Islands and three in Antarctica. The network of stations on the New Zealand mainland is shown in Figure 1.

The New Zealand Active Control Network

The network provides GPS carrier phase and code range measurements in support of three dimensional positioning activities throughout New Zealand. The PositioNZ network enables users to position points with an accuracy that approaches a few centimetres relative to New Zealand Geodetic Datum 2000 (NZGD2000), both horizontally and vertically.

The network has been established in partnership with GNS Science.

PositioNZ Data

PositioNZ stations are the highest accuracy points in the NZGD2000. A continuous tracking GPS receiver (Fig. 2) located at each station receives data from the constellation of GPS satellites that orbit the Earth.

Data from these satellites can be used to determine the precise position of points on the Earth's surface.

• The data from the PositioNZ stations are recorded at 30-second intervals and stored as RINEX format files.
• Data is available as hourly or daily files.
• Data is available free of charge at PositioNZ.
• There are no restrictions on the use of the RINEX data.
• International GPS Service (IGS) precise satellite orbits can be obtained from the International GNSS Service website.

Applications

LINZ distributes and archives GPS data from the PositioNZ network. This data can be used for a wide range of activities including:

• to enable geodetic, cadastral and other users to derive accurate positions, in terms of NZGD2000, with a single GPS receiver, single field party and, ultimately, without the need for their own processing software
• to enable connection of local surveys, eg. cadastral surveys, into the highest accuracy points in NZGD2000 (the Zero Order Network) to enable seamless and spatially consistent data sets to be developed and contribute to the local geodetic framework
• to provide greater confidence in the geometry and integrity of NZGD2000 through continuously collecting and analysing data and model the effects of crustal deformation
• to contribute to the IGS and to provide information for scientists for measuring plate tectonic movements and other applications
• to determine GPS satellite integrity, confirming that satellites are transmitting reliable data.

LINZ is currently looking at future developments of the PositioNZ network. These include increasing the number of stations, as well as providing real-time data streams.