New Zealand Terrain (Digital Elevation Model)
The Geographx DEM is a floating point terrain model with seamless NZ-wide coverage at a cell resolution of 8 metres.
The data was released in January 2012 and updated in July 2012. It replaces an earlier 20m DEM, supporting mapping at larger map scales and delivering increased detail in areas of low relief.
Elevation values have been extracted from the vector LINZ Topo50 data, and systematically interpolated using constrained linear triangulation with DEST post-processing and adaptive filtering.
The terrain is suitable for visualisation, terrain characterisation and cartographic representation.
The Geographx landcover texture maps are designer data, a detailed, easy to interpret and aesthetically pleasing representation of New Zealand topographic features, vegetation and landforms. The dataset consists of 115 flattened and tiled raster images providing seamless nation-wide coverage at a pixel resolution down to 4 metres.
The textures can be draped over terrain and visualised in static or dynamic 3D virtual environments. Or they can be used as canvases or basemaps, contextual frameworks on which to draw artwork or overlay additional land information.
Developed in 2012, the texture maps feature content derived from multiple sources. Prior to flattening the composite files contain up to 100 feature types, layered in hierarchal order. The dataset includes topographic features from LINZ Topo50, landcover from Landcare’s LCDB3, and relief shading derived from the Geograph 8m terrain.
Unlike many orthophotographs, the texture maps are free from cloud and clutter. Hill shading is consistent in depth and direction, there is no reflected glare from snow/water surfaces, and there there is no unintended variation in colour toning or saturation.
Because processing is scripted and non-destructive, Geographx is able to regularly update the texture maps as new data becomes available. We can also customise both content and appearance to meet any client specifications.