Why don't I see nice cartographic representation of data in this portal?
The LRIS portal is specifically designed for download of data sets. Visualisation and cartographic representations, i.e. maps, are provided only so far as is required to allow users to determine that they have found the appropriate data layer for their purpose. The strong focus on metadata delivery, particularly the easily understood Dublin Core metadata report, are also designed to facilitate data layer discovery as well.
This service assumes that you will download the data for use in your own GIS, where query, modelling and mapping can be undertaken. For those who don't currently have GIS software we recommended QGIS (http://qgis.org) which is an open source software application.
We plan to have a separate part of the portal offering on-line data visualisation, query and eventually modelling capabilities in the near future. This will replace our existing Geospatial Portal.
What do I do if I don't have my own GIS ?
We will post more information soon about options for accessing open source GIS software to at least be able to view and query data downloaded from the LRIS Portal. But we recommend QGIS (http://qgis.org) as a good entry level open source Windows GIS package.
Why am I not receiving notification emails after I have placed a request for data?
In some cases your internet providers SPAM filters may identify LRIS Portal support and notification emails as being SPAM. You may need to make firstname.lastname@example.org, email@example.com and firstname.lastname@example.org trusted senders in order to ensure your notification and support email are not redirected to your junk mail folder.
What formats are the data available in?
Landcare Research data is predominantly either ESRI shapefile or ESRI ArcInfo Coverage data for vector data, or as ESRI Grid or Imagine IMG format data for raster data. Most satellite imagery will be stored by Landcare Research as IMG format.
The LRIS Portal software handles all of these data formats except IMG. All IMG format will have been uploaded to the system as GeoTiff format.
Data downloads from the LRIS Portal can be in any of the following formats:
• For Vector GIS - ESRI shapefile or MapInfo TAB format
• For Raster GIS – GeoTIFF or ESRI ASCII GRID format
• For CAD – AutoCAD DWG format
• For Google Earth – KML format
If the data format that you can read with your GIS package is not available, or you think another format should be made available, please contact email@example.com.
What sort of data use agreement is the data available under?
In the initial release of the Portal, most of the data is available under a Data Use agreement created by Landcare Research. In the medium term, Landcare Research plan to release much of its data within the New Zealand Government Open Access and Licensing framework (NZGOAL). However, while NZGOAL is going through the Cabinet deliberation process, the outcome of which is expected to be known in the near future, we are unable to proceed any further with creating a specific use licence.
Some of your data is licensed under Creative Commons Use Licences. What is Creative Commons?
Creative Commons licences (also referred to as CC licences) permit the copying, the reuse, the distribution, and in some cases, the modification of the original owner’s creative work without having to get permission every single time from the rights holder.
The licence is attached to the content and is available in various forms, allowing the rights holder to retain a level of control over how their work is treated.
Creative Commons isn’t ideal for scientific data and work is taking place researching better forms of open science licensing models e.g. Science Commons.
You can find out more about Creative Commons at the Creative Commons web site (http://creativecommons.org/).
I can’t find the data I am looking for on your portal, where else can I look?
If you are looking for data you expected to find here and didn’t, please contact us at firstname.lastname@example.org and tell us what data you are after. We will try to help.
I have some data I’d like to add to the LRIS portal. How do I do that?
We are very interested in new data which has been derived from data you downloaded from the LRIS portal or data sets where you have augmented, for example by adding new data attributes. However, while the LRIS Portal is designed to allow anyone to add data to it, this functionality has been disabled for the first release.
If you are an employee of Landcare Research, please contact James Barringer about including your data in the LRIS Portal.
If you not an employee of Landcare Research but have data you think we might be interested in, please contact email@example.com.
In either case, we will provide you with a way to provide your data to us online and will work with you to publish your data.
What is metadata?
Metadata is loosely defined as data about data. This definition is easy to remember, but not very precise. The strength of this definition is in recognizing that metadata is data. As such, metadata can be stored and managed in a database, often called a registry or repository. Metadata is a concept that applies mainly to electronically archived data and is used to describe the
b) structure and
of data files with all contents in context to ease the use of the captured and archived data for further use. All environmental data should have metadata. Increasingly this is available as an XML file as well as in a human readable format. In either case the record will contain a description of the data, keyword tags, information about location, extent, lineage, conditions of use and contacts which are essential to understanding the spatial data layers content and making proper use of that data in spatial analyses.
The LRIS Portal stores the metadata about a Layer as an ISO 19115 compliant metadata record in XML, which is great for a computer, but not very easy for a person to read. We use Dublin Core to give you an easily digested view of the most important bits of the metadata for identifying a dataset and its value to you the user. (Dublin Core is a simple standard for metadata that shows only a subset of the full ISO metadata record.)
What ancillary documents are included with Downloads?
Most data downloads will include at least some ancillary documents. These will help you in understanding and using the data. Apart from a PDF version of the Dublin Core metadata record, the ancillary documents will usually include a data dictionary or some equivalent (e.g. in the case of a soil survey the appropriate soil survey report in PDF format). There may also be an ArcGIS layer file suggesting suitable symbology and data representation (.lyr file).
What are map projections?
A map projection is the representation of the spheroidal surface of the earth on a flat surface (a piece of paper or computer screen). The mathematical algorithms used to achieve the transformation depend on the specific purpose required, such as preservation of shape, correct area, direction, etc. Map projections are designed to deliver accuracy over a defined area, usually the larger the area the lower the accuracy.
For mapping purposes most of New Zealand is covered by a single projection. Between about 1980 and 2000 this was the New Zealand Map Grid (NZMG), but since 2000 this has transitioned to New Zealand Transverse Mercator (NZTM). You can still find some data sets using NZMG. The Chatham Islands has its own projection while the sub-Antarctic and northern Kermdec Islands are usually projected in latitude/longitude WGS84.
For more information on New Zealand projections please refer to http://www.linz.govt.nz/geodetic/datums-projections-heights/index.aspx.
Projections are also always defined in terms of a geodetic datum. This is a set of reference points on the Earth's surface against which position measurements are made. Horizontal datums are used for describing a point on the earth's surface, in latitude and longitude or another coordinate system. Vertical datums measure elevations or depths. Associated with the geodetic datum there is usually a model of the shape of the earth (the reference ellipsoid) to define a geographic coordinate system.
NZMG is defined in terms of the New Zealand Geodetic Datum 1949 (NZGD1949) and NZTM in terms of the New Zealand Geodetic Datum 2000 (NZGD2000). NZGD1949 was based on a different reference ellipsoid to NZGD2000. This means that coordinates are approximately 200 metres different between datums. There are three official transformations between NZGD2000 and NZGD1949 (see LINZ web site).
All data in the LRIS Portal is uploaded from its “native” projection – in most cases for Landcare Research data this means either New Zealand Map Grid (NZMG/NZGD1949) or New Zealand Transverse Mercator (NZTM/NZGD2000).
The LRIS Portal stores all uploaded data in its "native" projection but displays all data on-screen in WGS84 which is a global projection (http://en.wikipedia.org/wiki/World_Geodetic_System),
Data downloads from the LRIS Portal require the user to specifiy a projection. The most frequently used of which may be:
• New Zealand Transverse Mercator / New Zealand Geodetic Datum 2000 (EPSG:2193)
• New Zealand Map Grid / New Zealand Geodetic Datum 1949 (EPSG:27200)
• World geodetic System 1984 (EPSG:4326 Lat/Long)
• North Island Grid / New Zealand Geodetic Datum 1949 (EPSG:27291)
• South Island Grid / New Zealand Geodetic Datum 1949 (EPSG:27292)
Or one of the local circuit surveying projections for New Zealand
• Marlborough Circuit / New Zealand Geodetic Datum 1949 (EPSG:27220)
• Marlborough Circuit / New Zealand Geodetic Datum 2000 (EPSG:2120)
• Either in terms of NZGD1949 or NZGD2000.
What are coordinates/grid references?
Coordinates are set of values represented by the letters x, y, and optionally z or m (measure), that define a position within a spatial reference. Coordinates are used to represent locations in space relative to other locations.
All coordinates refer to a specific datum or projection. Before two coordinates can be compared they need to be defined in terms of the same system. The process to change coordinates between datums and projections is called either a conversion or a transformation.
For WGS84 these coordinates are in latitude and longitude which are angular measurements from the Earth's center of mass.
Latitude gives the location of a place on Earth north or south of the equator. Lines of Latitude are the imaginary horizontal lines shown running east-to-west (or west to east) on maps (particularly so in the Mercator projection) that run either north or south of the equator. Technically, latitude is an angular measurement in degrees (marked with °) ranging from 0° at the equator (low latitude) to 90° at the poles (90° N or +90° for the North Pole and 90° S or -90° for the South Pole).
Longitude is the geographic coordinate for east-west measurement. Constant longitude is represented by lines running from north to south. The line of longitude (meridian) that passes through the Royal Observatory, Greenwich, in England, establishes the meaning of zero degrees of longitude, or the prime meridian. Any other longitude is identified by the east-west angle, referenced to the center of the Earth.
For map projections such as NZMG and NZTM, a set of Cartesian coordinates in metres are defined to uniquely identify any point on the map by an easting and a northing. Because projections are mathematically defined with their origin in some sense centrally located, all projections have a false origin defined. This is a point in the south and west corner of the area to which the projection pertains which will nominally have the coordinates 0,0. This ensures that all coordinates will be positive numbers increasing towards the east and north.
In the case of NZMG, which is a unique form of projection, the origin point of the projection is at 41°S, 173°E latitude, a point somewhere near Nelson. For NZTM, as a Transverse mercator projection, the origin point is at 0°S, 173°E, a point located on the Equator but centred longitudinally on New Zealand. In order to avoid confusion between different projections relating to the same area, false origins may be set to ensure that coordinates never overlap. So, for example, the false origin under NZMG is 2,510,000E 6,023,150N while for NZTM the false easting is 1,600,000 and the false northing 10,000,000. The difference in false eastings always ensures that no part of New Zealand overlaps in coordinate space if the wrong projection is set. NZMG eastings will typically be in the “2 millions” amd NZTM coordinates in the “1 millions”.