Creative Commons Attribution 4.0 International
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This dataset was last updated on LINZ Data Service on 18 Aug 2016.
967d1a35-f448-9fde-a246-3088a3033de6
eng
utf8
dataset
dataset
omit
Toitū Te Whenua Land Information New Zealand
Chief Topographer
04 4600110
155 The Terrace
Wellington
6145
New Zealand
customersupport@linz.govt.nz
resourceProvider
2016-03-02
ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata
1.1
2193
NZ 8m Digital Elevation Model (2012)
http://geographx.co.nz
This 8m DEM was originally created by Geographx (http://geographx.co.nz) and was primarily derived from January 2012 LINZ Topo50 20m contours (https://data.linz.govt.nz/layer/768).
Spatial accuracy is nominally the same as for the LINZ source data: 90% of well-defined points are within ±22 metres horizontally and within ±10 metres vertically.
For a full description of the how the DEM was generated refer to this layer’s metadata.
The main criterion in its production was the detailed and accurate depiction of natural landforms. It is therefore suitable primarily for cartographic visualisation. Because it was created by the interpolation of 20m contours with post-processing and filtering it is not suitable for terrain analysis.
completed
Omit
Toitū Te Whenua Land Information New Zealand
Technical Leader, National Topographic Office
0800 665 463 or +64 4 460 0110
+64 4 472 2244
155 The Terrace
Wellington
6145
New Zealand
customersupport@linz.govt.nz
pointOfContact
notPlanned
*.xml
Unknown
New Zealand
theme
ANZLIC Jurisdictions
Version 2.1
2008-10-29
http://asdd.ga.gov.au/asdd/profileinfo/anzlic-jurisdic.xml#anzlic-jurisdic
ANZLIC the Spatial Information Council
custodian
unclassified
Copyright 2011 Crown copyright (c)
Toitū Te Whenua Land Information New Zealand and the New Zealand Government.
All rights reserved
copyright
Released under Creative Commons Attribution 4.0 International
license
grid
50000
eng
utf8
elevation
imageryBaseMapsEarthCover
https://data.linz.govt.nz/layer/51768-nz-8m-digital-elevation-model-2012/
dataset
dataset
The Geographx New Zealand Digital Elevation Model version 2.1 covers the three main islands of New Zealand (North Is, South Is, Rakiura/Stewart Is) at a cell resolution of 8 metres.
It is prepared primarily from 1:50 000 topographic data from Toitū Te Whenua Land Information New Zealand (the LINZ classes used are contour, height, coastline, island, lake, lagoon, pond, reservoir, sand, mud, shingle, reef, shoal, rock (polygons and points) and rock outcrop), with 3-second SRTM data (USGS, Shuttle Radar Topography Mission (February 2000), unfilled finished version B (2006). Global Land Cover Facility, University of Maryland - www.landcover.org) used in a supporting role.
The main criterion in its production is the detailed and accurate depiction of natural landforms. It is therefore suitable primarily for cartographic visualisation. It may also be useful for terrain analysis, before the acquisition of high-resolution data for a region of interest.
Spatial accuracy is nominally the same as for the LINZ source data: 90% of well-defined points are within ±22 metres horizontally and within ±10 metres vertically.
The DEM is initially derived by constrained triangulation, with post-processing using the DEST algorithm (Favalli M and M T Pareschi, “Digital elevation model construction from structured topographic data: the DEST algorithm”, J Geophysical Research 109 (2004)), followed by signal detection and filtering to suppress artifacts while preserving natural form. Processing is performed in Manifold System 8.
Waterbody elevations
In version 2.1, all LINZ waterbody classes (lake, lagoon, pond and reservoir) are given either a validated LINZ height, or an estimated height.
Validation was performed by correlating LINZ waterbody elevations to the height of the underlying contour, the correlation being used to identify outlying values, which were validated, excluded or (in the case of obvious typographical errors) corrected.
A revised correlation, along with constrained SRTM heights and information about local convexity or concavity, was then used to estimate all waterbody heights. Parameters were adjusted to minimize RMS difference between estimated height and validated LINZ heights.
Waterbodies with no LINZ elevation (or with an invalidated elevation) were then given the
estimated height.
Coastal elevations
Coastal features have been assigned representative elevations. The LINZ coastline and island
outlines depict not mean sea level, but high water mark (generally the line of visible debris), and
are assigned a constant elevation of 1.5m. Coastal sand, mud and shingle are given elevation 1.0m, while coastal rock, reefs and shoals are assigned 0.5m.
This layer was modified 01 March 2016 using 'gdalwarp' to covert the values in ocean regions to 'no data'. Ocean regions are determined by overlaying the LINZ Topo50 Coastlines and Polygons (https://data.linz.govt.nz/layer/1153-nz-coastlines-and-islands-polygons-topo-150k/)and converting those values outside the coastlines layer. This action was performed for each individual DEM tiles in a batched process. The projection used for the entire operation is NZTM.
For Windows: FOR %i in (*.tif) do (gdalwarp -s_srs EPSG:2193 -cutline ~\topo50_coastline.shp %i ~\dem_clip\%i)
For LINUX: find . -name '*.gdb' | xargs -P 3 -t -n1 -I % gdalwarp -s_srs EPSG:2193 -cutline ~\topo50_coastline.shp % ~\dem_clip\%
The result is a DEM for only the land regions of NZ.
unclassified
Copyright 2011 Crown copyright (c)
Toitū Te Whenua Land Information New Zealand and the New Zealand Government.
All rights reserved
copyright
Released under Creative Commons Attribution 4.0 International
license