Find common questions and answers about the LINZ Data Service and the datasets you can access through it.
On this page, you'll find questions and answers about:
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- What hydrographic data is currently available from the LINZ Data Service?
- The following hydrographic / maritime data is available:
- Data based on official Electronic Navigational Charts (ENCs) published by the New Zealand Hydrographic Authority Prior to loading onto this service, the S-57 data from these ENCs is converted to shapefile format.
- Digital maritime boundry definitions for New Zealand.
- Where can I obtain official Electronic Navigational Charts (ENCs)?
- For navigation, mariners should use official New Zealand ENCs - find out where you can purchase ENCs.
- Can data from the LINZ Data Service be used instead of Electronic Navigational Charts (ENCs) for navigation?
No. This data:
- does not replace official ENCs
- should not be used for navigation
- is not corrected for Notices to Mariners.
- Where can I find more information about feature and attribute codes used in the hydrographic data?
- Feature and attribute codes used are based on the IHO S-57 standard. Links to these documents are available from Hydrographic Standards and Regulations.
- Why is continuous coverage of hydrographic data not available at some scales?
- Coverage of data is limited to the extent of current published Electronic Nautical Charts (ENCs). Further data will be published on the LINZ Data Service as new ENCs are released.
- What horizontal datum is used for the hydrographic data?
- World Geodetic System 1984 (WGS84).
- What sounding datum is used for the hydrographic data?
- What layers of geodetic data are available in the LINZ Data Service?
Find general information about the geodetic datasets available.
- Where do I find more information on geodetic data found in the LINZ Data Service?
See the geodetic system webpages for full and comprehensive information on geodetic data, datums and coordinate conversions.
- Why is Antarctic data included in a separate layer?
- The Antarctic data is referenced in terms of Ross Sea Region Geodetic Datum 2000 (RSRGD2000) which covers the extent of the Ross Sea Region in Antarctica. The NZGD2000, which is the datum for the majority of geodetic data, only covers mainland New Zealand and off-shore islands.
- What is the difference between the 'geodetic marks' and 'geodetic vertical marks' layers?
- The geodetic marks layer includes information about all geodetic marks in the region, whereas the vertical marks layer includes information about all geodetic marks that have heights in terms of a local mean sea level datum.
- What is the geodetic survey control marks layer used for?
- This layer includes the geodetic marks which have been broken down into principle control networks. Each of these classifications has governing standards which make marks within these networks fit for a particular purpose. See survey control networks for more information.
- Does the LINZ Data Service have orthometric heights?
The Antarctic geodetic vertical marks and geodetic vertical marks layers contain information for all geodetic database marks that have orthometric heights.
The geodetic database also contains a large number of marks that only have ellipsoidal heights. These heights can be converted to orthometric heights using NZGeoid09 and the online coordinate conversion application. In the future, LINZ will automatically include these calculated orthometric heights in the vertical marks layers.
- Why is the data different to the original Bulk Data Extract or Landonline?
Firstly, some data in Landonline is not spatial;it obtains its ability to be represented spatially by linking to Landonline data that is spatial, such as parcels. Therefore data like appellations and titles utilise parcel objects. As part of undertaking this linking, the links were formatted and inserted as if that data existed in the original table. Examples include adding title references into the parcel table and creating title objects from the parcels.
Secondly, the Bulk data extract contains over 100 tables of linked data (it is highly normalised). This is consequently difficult to use on a day-to-day basis and requires extensive processing or knowledge to join it all together. Data was therefore aggregated to enable layers to stand on their own right. An example is the individual fields of an appellation which have been merged together and inserted into the parcels datasets.
Thirdly, some tables contain all the similar data, yet common usage (and even initial capture) deals with them separately, especially when quick maps are created using these layers as a basemap. An example is parcels; the primary parcels are separated from non-primary parcels (easements, covenants, etc), strata and linear parcels.
Fourthly, the intent of the data is to make available current data. Landonline retains almost all records and when they are superseded, marked historic or similar. Likewise as data is entered it will have a status of pending or similar. This data is not yet approved for release, so although it is in Landonline, it is not made available. Landonline also contains private information relating to workflow and system users. This is not public information and hence not released.
We are currently in the process of adding additional sets of property-related information to LDS that was previously only available through the full Bulk Data Extract.
- Why are there several different parcel layers?
Firstly, topologically some parcels are different. With parcels such as those defined by a line (eg a centreline easement) and parcels defined by a polygon, some GIS systems are unable to hold these in the same layer. Further, strata parcels hold many primary rights and yet to place them in the same layer as other primary parcels can generate topological issues. For this reason they are held separately.
Secondly, the parcels data is commonly used for base mapping and many users require a separation by type. For example, some users may wish to exclude roads so that a road centreline layer can be easily distinguished, or separate the hydro parcels so they can be coloured blue, etc. Although most GIS packages can undertake these separation processes on the fly, they can be processing intensive (especially with a national dataset). They have therefore been created to provide a quick start point for users.
Common combinations are expected to be:
- road, hydro, and land parcels, instead of using the primary parcels.
- primary parcels, non-primary parcels, strata and linear parcels to create all parcels.
- Why are layers with owner names restricted?
- Proprietor (owner) names are subject to the Privacy Act and some records are protected by non-disclosure directions or orders such as under the Domestic Violence legislation. Accordingly you may be required to remove such records from your previously downloaded data, and this is best achieved through the use of a restricted licence as opposed to the open New Zealand Creactive Commons Attribution 3.0 license.
- Why does the shape of my title include the access lot?
The intent of the titles layer is to show the land that the title has primary rights over. Some titles include for example, an undivided share in an access lot. Both lots are shown and neighbouring lots will likewise show in interest in the access lot. The fact that the title does not have a full and exclusive right to all of the land shown is indicated in the ‘spatial_extents_shared’ column. If you are interested in the list of titles associated with an individual parcel of land, refer to the ‘title’ column in the various parcels layers.
- Why do the parcel layers sometimes have two appellations?
Appellations are the textual descriptions that describe a parcel and every parcel must have at least one appellation. Due to the historical nature of the data (ie survey and titles were separate systems maintained by separate government departments), occasionally the same parcel was ‘described’ differently, eg in Otago, the difference between lots and allotments. Where there are both survey and title appellations and the link between the parcel and the title has been established, the survey appellation is listed first.
- Why are some parcels not contiguous (ie they are separated by other parcels)?
- Multi-polygons exist primarily for parcels that have a single survey appellation but may be physically divided. They are therefore in the same title (where a title exists). A common example is where a road cuts through a parcel, but two individual parcels were not created on the survey. On old survey plans, these would be shown with the parcels linked together with a vinculum (a symbol like a broken ‘s’). Under the Rules for Cadastral Survey 2010, surveyors are no longer allowed to create new multi-polygon parcels.
- Why are there gaps in the title layers when I can see that there are parcels in the same area?
Firstly, most Crown land does not have a title such as roads. (Note: some land owned by the Crown may have titles eg schools etc), therefore a ‘gap’ will be evident when overlaid with the parcels layer.
Secondly, due to the historical nature of the data (ie survey and titles were separate systems maintained by separate government departments) there are a number of titles that have not been linked to the parcel shapes in the cadastre. Until these are identified and linked (matched), they are unable to be shown. This also affects unit titles.
LINZ currently has a linking project underway to improve this survey/title match rate.
- Why are unit titles not in the various title layers or listed in the parcels layers?
Landonline does not have the functionality to formally link unit titles to parcels. This means that without these links, unit title information is not able to be shown in these simplified data layers, which are based on Landonline data, because they are a-spatial records only. If they are required they can be obtained from the existing Bulk Data Extract.
- Why does the road centreline overlap with another road centreline?
The answer to this is usually because some roads have two names and each road is therefore represented independently:
This situation arises in several instances:
- Some roads form the boundary between two Territorial Authorities (TA) and each TA has named it differently. For example, Rongotea Road (Manawatu DC); Longburn Rongotea Road (Palmerston North CC).
- Some State Highways share a length, for example State Highway 5 and State Highway 30 share the same length of road in Rotorua.
- A road may start and restart such as State Highways running through rural towns but there is addressing on both.
- Why are there road parcels but no corresponding road centreline?
- This may occur where paper roads exist. These are where land has been designated as legal road but an actual road has never been formed.
- Why does the shape of my title include the access lot?
Most road centrelines commenced as centrelines for legal roads, and with the introduction of electoral requirements these slowly evolved into a mix of cadastral, legal, topographic and sketched (which is where only the general location was known). Some centrelines were hybrids of all four, however many users continued to incorrectly assume that they were cadastral or legal road centrelines due to Landonline bringing forward a historical naming concept. This concept related to the paper environment when a line would be shown with a pecked symbol on the map to indicate the location of a road where the parcel boundaries provided no indication as to where the road might be. These pecked roads were generally referred to as non-cadastral roads. To mitigate the incorrect legality assumptions, the flag has been reconfigured to clearly indicate whether the road has been derived from parcel information or not. Refer to the layer metadata for additional historical information.
- Why are some addresses aggregated into ranges?
- These are used where an address range has been allocated by the Territorial Authority to a property or building, and are also used in Landonline as a means of recording multiple addresses in a property against a single address point. The use of individual address points is preferable to ranges, but in some cases ranges must be used to avoid clutter and enhance clarity.
- Why are some addresses not on the road frontage?
Address points are maintained for electoral purposes. The location of an address point for electoral purposes are defined in the Electoral Act (Part 5 Section 72). When adding or modifying the location of address points the following priorities are observed:
Dwelling in correct meshblock
Same property as dwelling
Correct side of physical road
Correct side of legal road
Same parcel as dwelling
Location of dwelling
Location of property entrance Note 5
- Why does this dataset not include meshblock data from Landonline?
Meshblocks are the property of Statistics New Zealand and may be downloaded from the Statistics New Zealand website (www.stats.govt.nz).
- Why are topographic roads and electoral road centrelines different?
Topographic roads represent physical identifiable roads and tracks (at 1:50,000 scale), whereas the cadastral road centreline layers have commonly been created to enable the location of official road names throughout New Zealand. They also indicate the approximate extents to which each road name applies.
The spatial representation of electoral road centrelines are indicative only. They do not necessarily represent formed road access, actual carriageway location or legal access.
- How can I access positional accuracy of parcels and other related data?
In general, data relating to urban areas will be positionally more accurate than rural ones. This is largely because a greater number of surveys have been undertaken in urban areas. When Landonline was developed, this differentiation was exacerbated as survey capture areas were defined and parcel boundaries built from the original boundary information, whereas in rural areas, the boundary information supplied came from digitised records (refer to the parcel layer metadata for greater detail).
Surveys are now all digitally captured, so when they are integrated into the parcel fabric, they will in turn improve the accuracy of boundaries around them. When surveys are integrated, the extent of the adjustment is created as a shape. These shapes can be used to identify areas of recent improvement (refer to the cadastral adjustments layer).
The exact assessment that LINZ makes relating to parcel boundaries is inferred from the nodes of individual survey marks placed or relocated by the cadastral surveyor (refer to the various geodetic and survey mark layers). By overlaying these marks with the parcels, this relationship can be mapped. In general, any mark with an order of less than 8 will be shown as accurately as the underlying survey and commonly suitable to overlay with aerial photography and satellite imagery.
LINZ is currently improving low accuracy areas through the Spatial Parcel Improvement project.
- What is the difference between the parcel vectors and the survey observations layers?
The parcel vectors list is a subset of the latest of the survey observations. The list contains only boundary vectors.
This layer has been constricted to enable users to easily access the best known dimension for parcels (bearings or distances). As the cadastre is continually being updated with new surveys, it is possible that the latest information may be different to other information created at an earlier date, eg dimensions on a printout of a Certificate of Title.
- What is the cadastral adjustments layer for?
Whenever a cadastral survey is integrated into Landonline, a mathematical process is undertaken to fit it into the existing cadastre (and/or the cadastre fitted to the survey). This process creates a polygon covering the extent of the work and therefore shows that the cadastral survey dataset has been integrated. In general, integrated cadastral survey datasets will be survey accurate and when these polygons are combined with the original survey capture areas, the data within the area is as positionally accurate as LINZ can determine.
- Why is there not a layer for every table in the existing Bulk Data Extract (BDE)?
In order to provide datasets that are easy to use and have the most commonly required attributes for general use, LINZ has created simplified layers that are based on the more complex Landonline data model. These layers are more suitable for GIS work than the full BDE layers. The full Landonline datasets remain available via the existing BDE. Many tables are also a-spatial and cannot be displayed as a map without linking them to a spatial object.
- Can my existing Bulk Data Extract (BDE) license for the restricted owner information be transferred to the LINZ Data Service?
- Existing BDE licenses for restricted owner information are not transferable to the LINZ Data Service. This is because the restricted license is a separate licence which will be linked to the registered users of the LINZ Data Service.
- Find out about requesting access to private layers belonging to the Owner Data - Controlled Access Group.
- Why does the survey plans layer not include the plan images?
The LINZ Data Service (with respect to data derived from Landonline) leverages existing processes that only unload textual data from Landonline. This means that the plan images are not available although search points, and header information about a survey plan are included. The header information forms the basis of the information about survey plans.
Find out about obtaining a copy of an individual survey plan.
- Why do the title layers not include the title images?
The LINZ Data Service (with respect to data derived from Landonline) leverages existing processes that only unload textual data from Landonline. This means that the title images are not available. The title layers leverage links to the parcel information so that their location can be provided. Please refer to the various title layers for additional information.
Find out about obtaining a copy of an individual land title.
- Why is there not a land XML delivery format?
The LINZ Data Service is primarily a mechanism to deliver GIS data in the most common GIS formats. Land XML can be obtained by licenced Landonline users.
In addition, the LINZ Data Service (with respect to data derived from Landonline) leverages existing processes that only unload textual data from Landonline. These existing processes do not always bring through all the data required to generate land XML identical to the land XML file generated by Landonline e-survey.
- What is aerial imagery?
- This is imagery collected by airborne sensors and cameras, and provides an accurate representation of the earth’s surface and features on it.
- What imagery is available?
- New Zealand’s most current publicly-owned aerial imagery, covering 95% of the country has been unlocked for public access and is now available on the LINZ Data Service (LDS).
- What areas does it cover?
- This imagery covers almost all of New Zealand. It is generally the more remote area where imagery is not available, such as mountain ranges.
- How do I access this imagery?
This imagery can be viewed and downloaded from the LINZ Data Service website.
- How is this imagery collected?
Aerial imagery is captured from airborne sensors and cameras. For decades, local government as well as central government agencies have purchased this imagery for managing land, and for making decisions about locations. This will continue to be gathered but procurement will be more consistent across government, and will ensure that it is open licensed so anyone can use it.
- What are the specifications of this imagery?
All the imagery on the LINZ Data Service is orthorectified imagery. The resolution varies based on the age and the requirement of when it was captured. Please refer to the metadata for each layer for specifics.
- Will you be making the imagery available as a map service?
LINZ will be trailing map services in the near future which will include imagery data. Stay tuned for more information in the LDS newsletter.
- How does it differ from Google earth?
This imagery has been adjusted to remove shadows and other obstructions, and is licensed so everyone can use it. While Google Earth has a lot of uses, it has some limitations such as a lack of metadata like date and accuracy information, which means it cannot be used for industries such as land development and agriculture, in the same way that this imagery can.
- Who can use this imagery?
Aerial imagery has a wide range of uses both for the public and private sector. There is an immediate benefit for councils in planning and resource management, while forestry and agriculture industries can use aerial imagery to help get better productivity out of the land. Aerial imagery is also a useful tool for planning construction and engineering works, and for managing large areas of land. Other uses include disaster recovery planning, archaelogy and land management.
- Why do the aerial imagery layers overlap at the edges?
The imagery datasets have been captured in regional blocks and although capture is usually required to the council boundary, it is common practise for imagery to bedelivered in full tiles.
- Are the imagery datasets colour balanced?
Each dataset is colour balanced as a set but not colour balanced to any other aerial captures. This is due to the fact that other aerial captures may have occurred in different years and by different aerial capture companies.
- Will this imagery be updated?
- LINZ has worked with Local Government to ensure that as they purchase new aerial imagery it will be made available on the LINZ Data Service on an open license at a consistent standard. LINZ will endeavor to provision data within a few months of acquisitions being delivered.At this stage, there is no official maintenance cycle and updates are tied to regional funding and procurement cycles.
- What is the benefit in making this available?
In the past, this imagery has been hard to find or access even when needed for rebuilding in Canterbury or for emergency response situations. Making it available on an open license and accessible through the LINZ Data Service should solve this problem, and reduce the chance of agencies doubling up on the imagery created. It also makes it available for industry to use and for use in creating value added products like smartphone apps.
- Do you have archival imagery?
LINZ will be investigating the potential to make archival imagery more accessible in a similar way to this aerial imagery. However, until then people will need to contact Archives New Zealand for archival imagery.