Creative Commons Attribution 4.0 International
You may use this work for commercial purposes.
You must attribute the creator in your own works.
This dataset was first added to LINZ Data Service on 16 Dec 2019.
766cd718-d847-7143-7620-3348d189261b
eng
utf8
dataset
dataset
Toitū Te Whenua Land Information New Zealand
Lidar Coordination Manager
04 4600110
155 The Terrace
Wellington
6145
New Zealand
customersupport@linz.govt.nz
pointOfContact
2020-12-10
ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata
1.1
2193
Auckland South LiDAR 1m DEM (2016-2017)
This layer contains the DEM for LiDAR data in the southern Auckland Region captured between 2016 and 2017.
- The DSM is available as layer [Auckland South LiDAR 1m DSM (2016-2017)](https://data.linz.govt.nz/layer/104382).
- The index tiles are available as layer [Auckland South LiDAR Index Tiles (2016-2017)](https://data.linz.govt.nz/layer/104409).
- The LAS point cloud and vendor project reports are available from [OpenTopography](https://portal.opentopography.org/datasets?loc=New%20Zealand).
LiDAR was captured for Auckland Council by AAM New Zealand between September 2016 to June 2017. These datasets were generated by AAM New Zealand and their subcontractors. Data management and distribution is by Toitū Te Whenua Land Information New Zealand.
Data comprises:
- DEM: tif or asc tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout
- DSM: tif or asc tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout
- Point cloud: las tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout
Pulse density is 4 pulses/square metre.
Vertical Accuracy Specification is +/- 0.2m (95%).
Horizontal Accuracy Specification is +/- 0.6m (95%).
Vertical datum is NZVD2016
completed
Toitū Te Whenua Land Information New Zealand
Lidar Coordination Manager
04 4600110
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 in this work is owned by Auckland Council
© Auckland Council
copyright
Released by LINZ under Creative Commons Attribution 4.0 New Zealand (CC BY 4.0) with:
Following Attribution:
"Sourced from the LINZ Data Service and licensed by Auckland Council, for re-use under CC BY 4.0."
For details see: https://www.linz.govt.nz/data/licensing-and-using-data/attributing-elevation-or-aerial-imagery-data
license
grid
1000
eng
utf8
elevation
ANZMet Lite Country codelist
Version 1.0
2009-03-31
http://asdd.ga.gov.au/asdd/profileinfo/anzlic-country.xml#Country
ANZLIC the Spatial Information Council
custodian
nzl
https://data.linz.govt.nz/layer/104318-auckland-south-lidar-1m-dem-2016-2017/
dataset
dataset
Data Acquisition:
Airborne Laser Scanner (ALS) data was acquired from a fixed wing aircraft between 9 September 2016 and 6 February 2017, using AAM Riegl Q1560 LiDAR system.
Survey Specification:
• Scanner: Riegl Q1560 - 2 laser channel system
• Half Scan Angle: ±20 & 29 degrees
• Laser Pulse Rate: 300kHz
• Laser Pulse Mode: Multipulse
• Laser Return: 1st, 2nd, 3rd... 7th and last
• File Format: ESRI ASCII Grid, LAS 1.2, ESRI Shapefile
• Horizontal Datum: NZGD2000
• Vertical Datum: NZVD2016
• Map Projection: NZTM2000
• Vertical Accuracy Specification: ±0.10m RMS
• Horizontal Accuracy Specification: ±0.30m RMS
The scan angle is < ±42 degrees per the data supplied to us not ±20 & 29 degrees referenced in the survey report specification. 18 LAS files are in LAS 1.2 format, the rest of the data is in LAS 1.3 format.
Airborne Laser Scanner (ALS) data was acquired from a fixed wing aircraft between 1 November 2016 to 29th June 2017 using AAM New Zealand's Riegl Q1560 - 2 laser channel system LiDAR system. This area includes Auckland Region covering southern suburbs and regions.
Classification of the point cloud followed the classification scheme below;
1 - Unclassified
2 - Ground
3 - Low Vegetation
4 - Medium Vegetation
5 - High Vegetation
6 - Buildings, Structures
7 - Low/High Points
9 - Water
10 - Bridge
12 - Overlap
Extra classifications found in three tiles were reclassified as Unclassified (1).
Rail (10) points were reclassified by LINZ as Bridges (17) per survey reference before providing the classified point cloud data to Open Topography.
Data Processing:
Reduction of the LiDAR data proceeded without any significant problems. Classification of the point clouds is to Level 3, with reference to ICSM LiDAR Specifications for NZ. Classification accuracy Required: 99% for ground points.
Discussion and clarification on Classification was undertaken between Nathan Sykes as client representative, and the AAM Team during the client review of the data, such as:
The pedestrian footbridges have been classed as structures, the intention was to use the bridge class for more substantial road bridges over water (unless it is a piped culvert)
Train carriages (temporary/moving objects) have been left in class 5, as assigned by classification routines.
The observation was made that the newer sensors, such as the Q1560, are very sensitive. They detect noticeably more atmospheric noise than older sensors (e.g. very light humidity that is not visible, can be detected). It’s not a defect. With these returns included and classified in the dataset, the user gets a feel for the structure of the data, e.g. in open areas where there are no “only returns” because the “first of many returns” are in the noise class.
The Digital Elevation (DEM) and Digital Surface Model (DSM) were derived using a point to TIN and TIN to Raster process, using Linear interpolation. Hydro flattening was undertaken in the DEM over non-tidal water bodies with surface area greater than 625 sq m, to the client specifications.
Tidal areas were flow within 1.5 hours of gazetted low tide (noting local variation in actual lowest water level)
Data Validation:
Ground data in this volume has been compared to test points obtained by field survey and assumed to be error-free.
Data classification has been manually checked and edited against any available imagery
Points to Note:
It was noted in tiles BB31_4425 and BB31_4325, there was significant flight line stepping between flights 2 and 10. This was caused by shifting sand dunes, rather than a system error.
The deliverables to LINZ were:
1m gridded bare earth digital elevation model (DEM)
1m gridded digital surface model (DSM)
Classified point cloud
Copyright of this work is owned by Toitū Te Whenua Land Information New Zealand
© LINZ
copyright
Released by LINZ under Creative Commons Attribution 4.0 International (CC BY 4.0) with:
Following Attribution:
"Sourced from the LINZ Data Service and licensed for reuse under CC BY 4.0"
For details see https://www.linz.govt.nz/data/licensing-and-using-data/attributing-linz-data
license