LINZ provides authoritative NZGeoid2016 in Sideris (.sid) format. This folder provides other formats of this file so it may be easily included in software packages. These alternative formats are unsupported by LINZ. https://www.linz.govt.nz/guidance/geodetic-system/coordinate-systems-used-new-zealand/vertical-datums/gravity-and-geoid/new-zealand-quasigeoid-2016-nzgeoid2016
Natural Resources Canada (.byn)
US National Geodetic Service (.bin)
Descriptions of the .byn and .bin formats are provided in the following pdf by Natural Resources Canada: https://natural-resources.canada.ca/sites/www.nrcan.gc.ca/files/earthsciences/pdf/gpshgrid_e.pdf
Sideris ASCII (.sid)
Trimble (.ggf)
International Service for the Geoid (ISG) (.txt)
Eye4Software (.geo)
GeoTiff (.tif) Can be downloaded from: https://data.linz.govt.nz/layer/53447-nz-quasigeoid-2016-raster/
Grid (.csv) Can be downloaded from: https://data.linz.govt.nz/layer/53418-nz-quasigeoid-2016/