Next phase of datum improvement work begins

The next phase of work to update and enhance the New Zealand Vertical Datum 2009 is set to begin tomorrow, Land Information Minister Maurice Williamson says.

The NZVD2009 provides a consistent reference point for measuring heights in New Zealand, its offshore islands and the continental shelf. A project to collect aerial gravity data to improve accuracy began last year.

Flights to collect South Island aerial gravity data are due to begin from Timaru tomorrow.

“An accurate national vertical datum is essential to ensure the accurate integration of geospatial data and the determination of global change, such as rises in sea level.

“An updated datum allows the construction and infrastructure industries to use GPS receivers to more accurately calculate the height of any location. This is used for planning water and sewage infrastructure that follows downhill inclines,” Mr Williamson says.

Land Information New Zealand, along with GNS Science and Victoria University, has already gathered airborne gravity data from most of the North Island, and a number of North island flights will also take place this year.

“Once the data has been collected, the results will be analysed in preparation for the release of an improved datum in 2016. It will be accurate to within three centimetres in developed areas,” Mr Williamson says.

The project marks the first time airborne gravity data has been collected on such a scale in New Zealand.