Tasman - Motueka River Valley LiDAR 1m DEM (2018-2019)

Tasman - Motueka River Valley LiDAR 1m DEM (2018-2019)

Toitū Te Whenua Land Information New Zealand

2018-11-15

This layer contains the DEM for LiDAR data in the Tasman Region including Motueka River Valley and surrounding area captured between 2018 and 2019.

- The DSM is available as layer [Tasman - Motueka River Valley LiDAR 1m DSM (2018-2019)](https://data.linz.govt.nz/layer/104812).

- The index tiles are available as layer [Tasman - Motueka River Valley LiDAR 1m Index Tiles (2018-2019)](https://data.linz.govt.nz/layer/104813).

- The LAS point cloud and vendor project reports are available from [OpenTopography](https://portal.opentopography.org/datasets?loc=New%20Zealand).

LiDAR was captured for Tasman District Council by Aerial Surveys from 15 November 2018 to 13 February 2019. These datasets were generated by Aerial Surveys 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 specification is at a minimum of 2.17 pulses/square metre.

Vertical datum is NZVD2016.

Data Acquisition:
Airborne Laser Scanner (ALS) data was acquired from a fixed wing aircraft on: 15th, 20th, 22nd, 29th, 30th Nov 2018, 7th Dec 2018, 15th Jan 2019, 13th Feb 2019, using Aerial Surveys Optech Orion H300 LiDAR system.

Survey Specification:
- Scanner: Optech Orion H300
- Flying Height: 1300 m AMGL
- Scan Angle: ±30.0 degrees
- Scan Frequency: 41.5 Hz
- Pulse Rate: 100 kHz
- Swath Overlap: 35%
- Points Per Square Metre: 2.17


Data Processing:
The LiDAR sensor positioning and orientation (POS) was determined using the collected GPS/IMU datasets and Applanix POSPac software.

Base Station: PP-RTX

Sounds Surveying Ltd field surveyed check sites that were used to verify the accuracy of the
processed ground dataset

The POS data was combined with the LiDAR range files and used to generate LIDAR point clouds in NZTM and ellipsoidal heights. This process was undertaken using Optech LMS LiDAR processing software. The data was checked for completeness of coverage. The relative fit of data in the overlap between strips was also checked.

Please refer to survey reports for height accuracy summary statistics.

The positional accuracy of the LiDAR data has been checked by overlaying Sounds Surveying Ltd surveyed data over the LiDAR data displayed coded by intensity. The data was found to fit well in position.

The point cloud data was then classified withTerraSolid LiDAR processing software into ground and above ground returns using automated routines tailored to the project landcover and terrain.

All product deliverables supplied in terms of NZTM map projection and NZVD2016 vertical datum.

Classification of the point cloud followed the classification scheme below:
1 - Unclassified
2 - Ground
3 - Low Vegetation
4 - Medium Vegetation
5 - High Vegetation
6 - Building
7 - Low Noise
9 - Water
18 - High Noise

Lakes and large rivers were hydroflattened in the Bare Earth Digital Elevation Model.

The deliverables to LINZ were:

1m gridded bare earth digital elevation model (DEM)
1m gridded digital surface model (DSM)
Classified point cloud

-41.4844732385 172.615080518 -41.0955128671 173.091794216

https://data.linz.govt.nz/layer/104811-tasman-motueka-river-valley-lidar-1m-dem-2018-2019/

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