The GSB26-NZGD2000 grid enables the conversion of normal-orthometric heights from the Gisborne 1926 local vertical datum directly to New Zealand Geodetic Datum 2000 (NZGD2000) ellipsoidal heights.
GSB26-NZGD2000 is published on a one arc-minute grid (approximately 1.8 kilometres) extending over the benchmarks that nominally define the extent of the Gisborne 1926 vertical datum (177.0° E to 178.6° E, 37.4° S to 39.0° S).
The conversion value is represented by the attribute “delta”, in metres.
This grid is a combination of New Zealand Quasigeoid 2016 [NZGeoid2016](https://data.linz.govt.nz/layer/3418) and the [GSB26-NZVD2016](https://data.linz.govt.nz/layer/3430) height conversion grid. Where NZGeoid2016 is the reference surface for the New Zealand Vertical Datum 2016 (NZVD2016), while the GSB26-NZVD2016 grid models the difference between the Gisborne 1926 vertical datum and NZVD2016 using the LINZ GPS-levelling marks.
More information on converting heights between vertical datums can be found [on the LINZ website](http://www.linz.govt.nz/data/geodetic-services/coordinate-conversion/converting-between-nzvd2016-nzgd2000-and-local-vertical-datums).
Source
**GSB26-NZGD2000 Version 20160627**
This grid is a combination of New Zealand Quasigeoid 2016 [NZGeoid2016](https://data.linz.govt.nz/layer/3418) and the [GSB26-NZVD2016](https://data.linz.govt.nz/layer/3430) height conversion grid.
GSB26-NZGD2000 is published on a one arc-minute grid (approximately 1.8 kilometres) extending over the benchmarks that nominally define the extent of the Gisborne 1926 vertical datum (177.0° E to 178.6° E, 37.4° S to 39.0° S).
The conversion value is represented by the attribute “delta”, in metres.
