Data

This dataset provides information about the position, position accuracy, mark name, mark type, condition and unique four letter code for geodetic marks in terms of New Zealand's official geodetic datum for the Ross Dependency.

This dataset only includes marks that are within Antarctica. These positions have been generated using geodetic observations such as precise differential GPS or electronic distance and theodolite angles measurements. The positions are either 2D or 3D depending of the availability of this measurement data.

The source data is from Land Information New Zealand's (LINZ) Landonline system where it is used by Land Surveyors. This dataset is updated daily to reflect changes made in the Landonline.

Accuracy

Geodetic marks with a coordinate order of 5 or less have been positioned in terms of Ross Sea Region Geodetic Datum 2000 (RSRGD2000) using precise differential GPS techniques. Marks with order 6 have been positioned in terms of RSRGD2000 using precise horizontal angles and distance measurements. Lower order marks (order 7 and greater) are derived from lower accuracy measurement techniques or historical datum transformations, and may be significantly less accurate.

The accuracy of RSRGD2000 coordinates is described by a series of 'orders' classifications. Positions in terms of RSRGD2000 are described by three-dimensional coordinates (latitude, longitude, ellipsoidal height). The accuracy of a survey mark is indicated by its order. Orders are classifications based on the quality of the coordinate in relation to the datum and in relation to other surrounding marks. For more information see www.linz.govt.nz/geodetic/datums-projections-heigh...

Note that the accuracy applies at the time the mark was last surveyed. Refer to the web geodetic database for historical information about mark coordinates.

Note also that the existence of a mark in this dataset does not imply that there is currently a physical mark in the ground - the dataset includes destroyed or lost historical marks. The geodetic database provides more information on the mark status, valid at last time it was visited by LINZ.

This dataset provides information about the position, height, height datum, height accuracy, mark name, mark type, condition and unique four letter identifier for geodetic marks that have an authoritative height in terms of a vertical datum.
Heights are in datums defined at www.linz.govt.nz/geodetic/datums-projections-heigh....

All marks will have positions in terms of New Zealand’s official geodetic datum for Antarctica, Ross Sea Region Geodetic Datum 2000 (RSRGD2000). The horizontal positions of marks are provided for approximate location purposes only.

This dataset only includes marks that are within the Antarctic region. The height data for these marks have been generated primarily using precise vertical angle and slope distance measurements from datum tide gauges. Some have been generated from levelling data.

The source data is from Land Information New Zealand's (LINZ) Landonline system where it is used by Land Surveyors. This dataset is updated daily to reflect changes made in the Landonline.

Accuracy

The accuracy of normal-orthometric heights are described by height orders.

For more information see www.linz.govt.nz/geodetic/datums-projections-heigh....

Note the accuracy applies at the time the mark was last surveyed - see the geodetic database for historical information about height coordinates.

The AUK46-NZGD2000 grid enables the conversion of normal-orthometric heights from the Auckland 1946 local vertical datum directly to New Zealand Geodetic Datum 2000 (NZGD2000) ellipsoidal heights.

AUK46-NZGD2000 is published on a one arc-minute grid (approximately 1.8 kilometres) extending over the benchmarks that nominally define the extent of the Auckland 1946 vertical datum (174.0° E to 176.2° E, 36.1° S to 38.0° S).

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

This grid is a combination of New Zealand Quasigeoid 2016 NZGeoid2016 and the AUK46-NZVD2016 height conversion grid. Where NZGeoid2016 is the reference surface for the New Zealand Vertical Datum 2016 (NZVD2016), while the AUK46-NZVD2016 grid models the difference between the Auckland 1946 vertical datum and NZVD2016 using the LINZ GPS-levelling marks.

More information on converting heights between vertical datums can be found on the LINZ website.

The AUK46-NZVD2016 grid enables the conversion of normal-orthometric heights from the Auckland 1946 local vertical datum to the New Zealand Vertical Datum 2016 (NZVD2016).

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

This conversion and NZVD2016 are formally defined in the LINZ standard LINZS25009.

AUK46-NZVD2016 is published on a two arc-minute grid (approximately 3.6 kilometres) extending over the benchmarks that nominally define the extent of the Auckland 1946 vertical datum (174.0° E to 176.2° E, 36.1° S to 38.0° S).

The height conversion grid models the difference between the Auckland 1946 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. From the GPS-levelling marks the expected accuracy of AUK46-NZVD2016 is better than 2 centimetres (95% Confidence interval).

More information on converting heights between vertical datums can be found on the LINZ website.

The Auckland 1946 to NZVD2016 Conversion Raster provides users with a two arc-minute (approximately 3.6 kilometres) raster image of the conversion of normal-orthometric heights from the Auckland 1946 local vertical datum to the New Zealand Vertical Datum 2016 (NZVD2016).

The conversion value is represented by the attribute “O”, in metres.
This conversion and NZVD2016 are formally defined in the LINZ standard LINZS25009.

The height conversion grid models the difference between the Auckland 1946 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. From the GPS-levelling marks the expected accuracy is better than 2 centimetres (95% Confidence interval).

More information on converting heights between vertical datums can be found on the LINZ website.

The BLF55-NZGD2000 grid enables the conversion of normal-orthometric heights from the Bluff 1955 local vertical datum directly to New Zealand Geodetic Datum 2000 (NZGD2000) ellipsoidal heights.

BLF55-NZGD2000 is published on a one arc-minute grid (approximately 1.8 kilometres) extending over the benchmarks that nominally define the extent of the Bluff 1955 vertical datum (168.2° E to 168.9° E, 46.3° S to 46.8° S).

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

This grid is a combination of New Zealand Quasigeoid 2016 NZGeoid2016 and the BLF55-NZVD2016 height conversion grid. Where NZGeoid2016 is the reference surface for the New Zealand Vertical Datum 2016 (NZVD2016), while the BLF55-NZVD2016 grid models the difference between the Bluff 1955 vertical datum and NZVD2016 using the LINZ GPS-levelling marks.

More information on converting heights between vertical datums can be found on the LINZ website.

The BLF55-NZVD2016 grid enables the conversion of normal-orthometric heights from the Bluff 1955 local vertical datum to the New Zealand Vertical Datum 2016 (NZVD2016).

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

This conversion and NZVD2016 are formally defined in the LINZ standard LINZS25009.

BLF55-NZVD2016 is published on a two arc-minute grid (approximately 3.6 kilometres) extending over the benchmarks that nominally define the extent of the Bluff 1955 vertical datum (168.2° E to 168.9° E, 46.3° S to 46.8° S).

The height conversion grid models the difference between the Bluff 1955 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. From the GPS-levelling marks the expected accuracy of BLF55-NZVD2016 is better than 3 centimetres (95% Confidence interval).

More information on converting heights between vertical datums can be found on the LINZ website.

The Bluff 1955 to NZVD2016 Conversion Raster provides users with a two arc-minute (approximately 3.6 kilometres) raster image of the conversion of normal-orthometric heights from the Bluff 1955 local vertical datum to the New Zealand Vertical Datum 2016 (NZVD2016).

The conversion value is represented by the attribute “O”, in metres.
This conversion and NZVD2016 are formally defined in the LINZ standard LINZS25009.

The height conversion grid models the difference between the Bluff 1955 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. From the GPS-levelling marks the expected accuracy is better than 2 centimetres (95% Confidence interval).

More information on converting heights between vertical datums can be found on the LINZ website.

Coordinates computed from surveys undertaken after the 14 February 2016 Canterbury earthquake. These should be consistent with any observations made after this earthquake (neglecting any localised deformation such as that due to liquefaction).

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

These coordinates are only provisional. Analysis is ongoing as further data is collected. Coordinates were calculated using SNAP v2.5.33. Stations were constrained using coordinates of distant PositioNZ continuous GNSS stations that were unaffected by the earthquake.

The standard deviations of coordinates are 0.01m horizontally and 0.02m vertically, relative to the PositioNZ network.

Coordinate changes due to the earthquake have been calculated by comparing pre and post-earthquake coordinates. Pre-earthquake coordinates were calculated relative to public and private continuous GNSS stations. These continuous GNSS stations had data processed for several days early in 2016 (before the earthquake). Other pre-earthquake geodetic data was then readjusted with the continuous GNSS data. Note that this means these coordinate changes may differ slightly from those that would be calculated by comparing the post-earthquake coordinates with those currently in the Geodetic Database.

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

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. This layer contains coordinates computed from GNSS fast static and network RTK surveys undertaken after the Canterbury earthquakes. It also includes Lyttelton Vertical Datum 1937 and Christchurch Drainage Datum heights, derived from the GNSS data.

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

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 and other public and private organisations. No precise levelling data has been used.

The uncertainty (one standard deviation) is 0.02m horizontally, and 0.03m vertically for NZGD2000 ellipsoidal heights. The uncertainty (one standard deviation) of the Lyttelton Vertical Datum 1937 and Christchurch Drainage Datum heights is 0.05m.

The coordinates calculated prior to 2010-09-04 have been calculated from a combined adjustment including LINZ data and additional data provided by public and private organisations. These coordinates differ from those in the Geodetic Database and more accurately reflect the position of the mark immediately prior to the 2010-09-04 earthquake.

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.

Lyttelton Vertical Datum 1937 heights have been computed from NZGD2000 ellipsoidal heights by subtracting NZGeoid2009 geoid heights and adding an offset of 0.47m to bring in terms of Lyttelton Vertical Datum 1937. Christchurch Drainage Datum (CDD) heights have been computed in the Christchurch area from NZGD2000 ellipsoidal heights by subtracting NZGeoid2009 geoid heights and adding an offset of 0.523m (specifically calculated for Christchurch City) to bring in terms of Lyttelton Vertical Datum 1937 (for Christchurch) and a further offset of 9.04m to bring in terms of CDD.

The model used to estimate whether movements greater than 2cm occurred at a mark (excluding those due to liquefaction or other localised deformation) after the 2010-09-04 earthquake was provided by GNS Science (Darfield_Sep2010_model_8.5_grid_displacements_calcs.xls). The model used to estimate whether movements greater than 2cm occurred at a mark (excluding those due to liquefaction or other localised deformation) after the 2011-02-22 earthquake was provided by GNS Science (Chch_Feb2011_geodetic_source_model_3.21.xls). The model used to estimate whether movements greater than 2cm occurred at a mark (excluding those due to liquefaction or other localised deformation) after the 2011-06-13 earthquake was provided by GNS Science (Chch_Jun2011_geodetic_source_model_0.4.xls). The model used to estimate whether movements greater than 2cm occurred at a mark (excluding those due to liquefaction or other localised deformation) after the 2011-12-23 earthquake was provided by GNS Science (Chch_Dec2011_geodetic_source_model_0.2.xls).

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

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