Tagged: land geodesy - Page 2

This layer contains the index tiles for LiDAR data from the Wellington region captured in 2013.
The DEM is available as layer Wellington LiDAR 1m DEM (2013).
The DSM is available as layer Wellington LiDAR 1m DSM (2013).
The LAS point cloud is available from OpenTopography.

Lidar was captured for Greater Wellington Regional Council by Aerial Surveys in 2013. The datasets were generated by Landcare Research. The survey area includes Wellington, Porirua, Lower Hutt, Upper Hutt, Wairarapa, and Kapiti. Data management and distribution is by 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 1km x 1km tile layout

Data was collected at >1 pulse/square metre pulse density. Attributes include:
-Elevation
-Intensity values
-Return number
-Adjusted GPS time
-Classification

Vertical datum is NZVD2016

The relationship between the GRS80 ellipsoid and the New Zealand Vertical Datum 2016 (NZVD2016) is modelled by the New Zealand Quasigeoid 2016 (NZGeoid2016). The relationship value is represented by the attribute “N”, in metres.

This relationship and NZVD2016 is formally defined in the LINZ standard LINZS25009.

NZGeoid2016 can be used to convert New Zealand Geodetic Datum 2000 (NZGD2000) ellipsoidal heights to NZVD2016 normal-orthometric heights.

The conversion value is represented by the attribute “N”, in metres.

NZGeoid2016 is published on a one arc-minute grid (approximately 1.8 kilometres) over the New Zealand continental shelf (160° E to 170° W, 25° S to 60° S).

NZGeoid2016 was calculated by enhancing the EIGEN-6C4 global gravity model with, terrestrial, ship-track, satellite and airborne gravity data. GPS-levelling observations were not used to compute NZGeoid2016.

Users may also be interested in transforming heights to any of the 13 historic local vertical datums used in New Zealand using the appropriate datum relationship grid displayed in the NZ Height Conversion Index.

More information on these transformations is available on the LINZ website.

For further information about this dataset, see the Canterbury earthquake information.

Coordinates computed by adding the effects of deep-seated movement to survey points that had authoritative survey-accurate digital cadastre (SDC) coordinates immediately prior to 4 September 2010 (the first Canterbury earthquake). Marks that did not have SDC status at that time are not included in the dataset. Deep-seated movements were evaluated using the NZGD2000 deformation model.

• The 'nod_id' column is the Landonline node id. This is the unique identifier for the mark.
• The 'current_name' column is the Landonline mark name. Many boundary marks do not have a name recorded in this dataset, because this information has not been digitally captured.
• The 'east_mtpleatm2000' and 'north_mtpleatm2000' columns are the east and north coordinates (metres) in terms of the Mt Pleasant 2000 transverse mercator projection. Rounded to the nearest centimetre.
• The 'coord_order' column is the Landonline coordinate order immediately prior to 4 September 2010.

The estimated absolute uncertainty of these coordinates is 0.09m at the 95% confidence level.

These coordinates are intended for the use of Licensed Cadastral Surveyors when locating boundaries in Christchurch, in accordance with the Rules for Cadastral Survey 2010 and associated guidance, particularly guidance relating to the earthquakes.

This layer contains the DEM for LiDAR data from the Rangiora area captured in 2014.
The DSM is available as layer Canterbury - Rangiora LiDAR 1m DSM (2014).
The index tiles are available as layer Canterbury - Rangiora LiDAR Index Tiles (2014).
The LAS point cloud and vendor project reports are available from OpenTopography.

Lidar was captured for Waimakariri District Council and Environment Canterbury Regional Council by Aerial Surveys in March – June 2014. The datasets were generated by Aerial Surveys and their subcontractors. The survey area includes the Rangiora township area and the lower Ashley, Eyre, and Waimakariri river channels. Data management and distribution is by 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

Planned pulse density is 1 pulse/square metre.

Vertical datum is NZVD2016.

For further information about this dataset, see the Kaikoura earthquake information.

It is likely that many of these coordinates will be updated multiple times as marks move due to aftershocks and ongoing post-seismic deformation. It is therefore critical that the datum version and coordinate epoch date are recorded with any coordinates sourced from this dataset, along with the date the coordinates were accessed or downloaded.

These coordinates are computed from Continuously Operating Reference Station (CORS) data and geodetic surveys undertaken after the 14 November 2016 Kaikoura earthquake. They reflect earthquake movements up until the epoch date that is associated with each coordinate. Where possible, coordinates sourced from this dataset for use as control or calibration points in a project should be at the same or similar epochs. If not, post-seismic deformation may mean that new observations or coordinates do not fit well with these coordinates. Coordinates used as control or calibration points should also be well-distributed over the project area, so that any discrepancies resulting from the survey date being significantly different from the coordinate epoch date can be identified. If such discrepancies are identified, it may be necessary to use the LINZ PositioNZ-PP online processing service to generate control coordinates at the same (or nearly the same) epoch as the survey date.

Coordinates were calculated using SNAP v2.5.48. The origin of non-CORS coordinates is PositioNZ CORS that have been updated to include earthquake movements.

The 95% confidence interval uncertainties of coordinates are 0.02m horizontally and 0.03m vertically, relative to the PositioNZ network, at the epoch specified. In areas experiencing significant ongoing seismic activity, coordinates at the same mark at other epochs may differ by more than these uncertainties.

These coordinates are suitable for use in surveys and other geospatial positioning activities in the area impacted by the Kaikoura earthquake.

The deformation model associated with the NZGD2000 datum was updated, nominally at 1 August 2013. The actual update of LINZ data took place on 14-15 December 2013. This update involved reverse patches, which means that the "reference coordinates" of features were updated. The main updates relate to the Christchurch earthquakes. The patch also updated coordinates affected by other South Island earthquakes since 2000.

These updates have been incorporated into Landonline and resulted in spatial updates to all features in the affected areas.

This data set contains contours indicating the extent and magnitude of the coordinate changes to assist in assessing the impact of this update on client data sets. This dataset is also available as a polyline.

For more information see here

This layer contains the DSM for LiDAR data from the Christchurch and Selwyn areas captured in 2015.
The DEM is available as layer Canterbury - Christchurch and Selwyn LiDAR 1m DEM (2015).
The index tiles are available as layer Canterbury - Christchurch and Selwyn LiDAR Index Tiles (2015).
The LAS point cloud and vendor project reports are available from OpenTopography.

Lidar was captured for Environment Canterbury Regional Council by AAM between 5 October and 7 November 2015. The datasets were generated by AAM and their subcontractors. The survey area includes Christchurch City and parts of the Selwyn district. Data management and distribution is by 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

Planned pulse density is 4 pulses/square metre.

Vertical accuracy specification is +/- 0.20m (95%).

Horizontal accuracy specification is +/- 1.00m (95%).

Vertical datum is NZVD2016.

This layer contains the index tiles for LiDAR data from the Christchurch and Selwyn areas captured in 2015.
The DEM is available as layer Canterbury - Christchurch and Selwyn LiDAR 1m DEM (2015).
The DSM is available as layer Canterbury - Christchurch and Selwyn LiDAR 1m DSM (2015).
The LAS point cloud and vendor project reports are available from OpenTopography.

Lidar was captured for Environment Canterbury Regional Council by AAM between 5 October and 7 November 2015. The datasets were generated by AAM and their subcontractors. The survey area includes Christchurch City and parts of the Selwyn district. Data management and distribution is by 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

Planned pulse density is 4 pulses/square metre.

Vertical accuracy specification is +/- 0.20m (95%).

Horizontal accuracy specification is +/- 1.00m (95%).

Vertical datum is NZVD2016.

This layer contains the DEM for LiDAR data from the Kaikoura area captured in 2012.
The DSM is available as layer Canterbury - Kaikoura Lidar 1m DSM (2012).
The index tiles are available as layer Canterbury - Kaikoura Lidar Index Tiles (2012).
The LAS point cloud and vendor project reports are available from OpenTopography.

Lidar was captured for Environment Canterbury Regional Council by Aerial Surveys in 2012. Note that this capture was prior to the significant vertical and horizontal displacements from the 2016 Kaikoura earthquakes. The datasets were generated by Aerial Surveys and their subcontractors. The survey area includes the Kaikoura township area and adjacent coastal strips. Data management and distribution is by 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

Data was collected at >1 pulse/square metre pulse density. Attributes include:
-Elevation
-Intensity values
-Return number
-Adjusted GPS time
-Classification

Vertical accuracy specification is +/-0.2m (@ 95% confidence)
Vertical datum is NZVD2016

The Canterbury region of New Zealand experienced a sequence of significant earthquakes during 2010 and 2011. These earthquakes occurred on 2010-09-04, 2011-02-22, 2011-06-13 and 2011-12-23. The coordinates in this layer account for all significant movements relating to these, so should be consistent with any observations made after the last earthquake to affect a given area (neglecting localised deformation such as that due to liquefaction).

Users may also be interested in the more comprehensive data in the companion layer Canterbury Earthquake Geodetic Marks (2010, 2011) - Comprehensive.

These coordinates are only provisional. Analysis is ongoing as further data is collected. Coordinates were calculated using SNAP v2.3.61. Stations were constrained using coordinates calculated by GNS Science. Some coordinates were calculated from data provided by Christchurch City Council. No precise levelling data has been used.

The estimated accuracy is 0.02m horizontally and 0.03m vertically.

The deformation model igns2011_working.grd calculated from a model (v4) provided by GNS Science on 28 April 2011 was used to remove secular deformation.

These coordinates are suitable for use in surveys and other geospatial activities in Canterbury and Christchurch.

For further information about this dataset, see the Canterbury earthquake information on the LINZ website.