21 July 2016
Elevation and building outlines data, bathymetric indexes and new aerial imagery
The open data just keeps coming. Over the last two months we have released two new pilot datasets – elevation and building outlines. Use these datasets then give us your feedback to help us understand the benefit of investing in these datasets for national coverage.
Issue 21, July 2016
Auckland elevation data now open
For the first time, you can now grab LiDAR (elevation) data from LDS. The available data is from the Auckland region and is part of LINZ’s work to coordinate the capture of national elevation data to improve New Zealand’s resilience to natural events. This is the first of many elevation datasets we will publish this year.
A bare earth Digital Elevation Model (DEM) and Digital Surface Model (DSM), as well as accompanying index tiles, will be made available for each dataset we publish. The source point cloud data is also available by direct request to LINZ.
We have also just opened consultation on draft specifications for the capture of aerial LiDAR. We welcome your feedback on these specifications.
LINZ has released another exciting pilot dataset on the LDS. This contains building outlines for the Canterbury, Hawke’s Bay and Waikato regions. A building outline is a 2D shape of the edge of a building as visible from aerial imagery (most commonly the roofline edge), and includes spaces such as decks, garages and porches.
The outlines were extracted from the aerial imagery available on LDS, collected as part of the LINZ national imagery coordination programme. This work was undertaken by Ecopia Tech Corporation, who developed an automated approach to extract building outlines using machine learning.
Use this dataset for activities such as flood modelling and topographic mapping then let us know how well it meets your needs by taking a short survey. Your feedback will help us understand the value of establishing a national building outlines dataset.
As promised in May, we have now released more indexes to our bathymetric data. You can now use these indexes to identify bathymetric data and scanned survey sheets LINZ holds for the Ross Sea region. We have also updated the New Zealand bathymetric data indexes, and have released indexes for the scanned survey sheets for New Zealand waters.
As part of the next general update of hydrographic data, LINZ will be making changes to the 400+ vector datasets. To ensure our data is fit for purpose, we will replace all the numeric code values in the datasets with human readable text. For example, COLOUR=1 is now COLOUR=Black. This will also mean schema changes to almost half of the vector datasets to reflect the changes in data type, for example, from numbers to plain text.
We’ve just published four new imagery datasets on LDS. This includes brand new urban aerial imagery for three areas that haven’t had high resolution imagery (0.1m) before – Wairoa, Northland and Hamilton. We’ve also published new rural imagery for the Hawkes Bay.
Imagery in these datasets was captured during summer 2014/15 and replaces imagery last captured in the summer of 2010/11.
In June, LINZ released the New Zealand Vertical Datum 2016 (NZVD2016). It is the new official vertical datum for New Zealand, and replaced NZVD2009.
NZVD2016 defines an improved reference geoid, New Zealand Quasigeoid 2016 (NZGeoid2016), that includes recently captured airborne gravity observations to fill previous data gaps in mountainous regions and the littoral zone surrounding the nation. It also published a set of conversion grids to better model the differences between NZVD2016 and the 13 major historic local vertical datums.
The NZGeoid2016 grid that defines NZVD2016 and the 13 local datum conversion grids are currently being tested and will be available on LDS by the end of July 2016.
The new datum and conversion grids will be off interest to anyone wishing to transform NZGD2000 and GNSS derived ellipsoidal heights to NZVD2016 and any of the 13 local datums. The improved local datum conversion grids provide a more consistent and repeatable height transformation at the local level. The new national datum will be an advantageous reference surface for large, regional or national scale datasets such as LIDAR or aerial imagery.
If you’re interested in our new address and roads data, you can now download updated BETA data. The updated data has been extracted from a test database and all identifiers have changed. The data is up to date and correct as at 3 July.
The final testing of our new system for address and roads data is underway. Once testing is complete we’ll let you know when these datasets will go live.
Email: firstname.lastname@example.org or phone: 027 566 5251