The project map displays project area, showing for example the bathymetry, vessel tracks, and sampling stations for the different sampling methods. Move the cursor to the desired sampling method (âLayersâ) and click the button to display the stations on the map. Place the cursor over a station or a station trackline (as shown when the towed gear stations such as those using the Brenke sled and beam trawl are highlighted) and the station number and associated location, date and time, and depth data will be displayed.
The main methods used in the surveys are described briefly. Click on the method name below the description for further information and images showing the equipment and its use.
NIWA stores digital images from research surveys in its Atlas, image database library. To access images from the Project site click on the âView imagesâ button. A new page will open at the NIWA Atlas site and you will be able to enter via the âClick here for public accessâ button.Â The Public Access Gallery allows you to search on common and species names, as well as display the distribution of sampling sites of images and faunal groups. For this type of display, click âMap Searchâ on the far left of the Public Access Gallery screen. Next click the âAssets-imagesâ box on the right side of the screen (a tick should appear) and click âupdate map imageâ to display the location of the images. Zoom in using the available navigation tools or by drawing a box with the cursor, locate an image point (note the latitude and longitude of the image point will be displayed in blue to the left of the map under the scale bar). Click on the first Marquee selection tool, then on an image point and all images from that location will be displayed. To exit use the back button until you return to the Oceans Survey 20/20 site.
Access to many of the datasets and the associated metadata collected during Oceans2020 is available through the Search Data link. Click on this and you will be able to search the metadata site. Metadata for each dataset describe the type of data collected, the location of the collection, the form of the data, any limitations or constraints in the use of the data, and the person who is the point of contact should you have enquiries. Most datasets are available for download, but should you require use of large datasets that cannot be made available for download you will need to email the point of contact given in the metadata.
The portal uses industry standard web services to retrieve the map layers displayed. Much like you can use any standards compliant web browser to view a web site, you can use any compliant GIS, desktop mapping or web mapping application to access and display this map data.
The standards supported are WMS (Web Map Service) and WFS (Web Feature Service). The WMS service provides a pre-drawn map that your local application displays on screen and the WFS provides a set of feature records that your client plots locally on your map. The portal website accesses the map layers from a NIWA server using these protocols, and other applications can also access these map layers directly from this server.
The explanation here will use the Open Source GIS tool Quantum GIS (QGIS) accessing Bay of Islands map layers as an example, but a similar process will apply to most other mapping applications.
QGIS is free, like the other components of this portal, and can be downloaded from www.qgis.org and installed on your computer. Versions 1.3 and 1.5 of QGIS were used for testing the WMS & WFS services NIWA provides to the portal.
This will create a new map layer in QGIS showing the Bay of Islands bathymetry layer.
Assuming you have QGIS installed and working, start it and open the WMS tool (click on the globe icon on the tool bar), choose âNewâ to create a new WMS data source.
Give the layer a meaningful name for your purposes, it is simply how you want it listed on your system, so âBOI bathymetryâ is suitable. The URL to enter to access the map layer from the NIWA server is http://boi.wms.niwa.co.nz/cgi-bin/bathymetry. Enter this in the URL field. You do not need any authentication to access this, so you can save the entry by clicking OK at this point.
Ensure this is the currently selected WMS layer (clicking the WMS layer title provides a pick list of saved entries) and click Connect. At this point, QGIS will ask the remote server (at the URL specified) for what is called a âcapabilities documentâ. This document describes the datasets & various parameters & metadata available from this WMS server. QGIS will read this document and present you with a list of available map layers. In this case, assuming it is all working, there will be one layer only, called bathymetry. This is available in different image formats, GIF, JPG, PNG & TIF. Generally PNG will work best, as GIF has limited colours, JPG images do not support transparency very well and TIF images tend to be larger, thus slower to retrieve. Select PNG format, then click âAddâ to add the layer to your map. That should be all you need to do, and the layer should be shown on your map.
You can zoom in and out, pan or turn the layer off or on using the usual QGIS controls, just like a layer read from a local data source. As you zoom in, the NIWA server will provide new maps, adjusting the resolution to fit your view automatically. As the map is entirely provided by the remote server, you cannot control or change it locally, merely enable and disable it, or move it within the stack of layers you are viewing.
To add a WFS layer to QGIS, you first need to enable the WFS plugin (Recent versions of QGIS are adding new capabilities as optional modules, so you do not need to have buttons for functions you don't need). Choose Plugins from the main menu, choose manage plugins, scroll down to find âWFS pluginâ and enable it. If there is no WFS plugin listed, you can download it by selecting âFetch python pluginsâ from the main âPluginsâ menu, then enable it as described above. This will add a new menu icon - a circle with red lines inside.
The process for adding a WFS data source is similar to that for a WMS source described above. Click the WFS icon, choose âNewâ, assign a local name for the layer, the URL & save by clicking OK. The name can be DTIS, the URL should be http://boi.wms.niwa.co.nz/cgi-bin/stations and no user authentication is required.
You can now select this from the WFS tool, QGIS will retrieve a WFS capabilities document, and in this case, you will see that several layers are available - corresponding to the method layers shown in the portal map. In this case we will select just the DTIS layer, to match the name we gave it, but you can select any of the layers. Click OK, and this layer will be added to your map.
Note that âlayersâ may be provided in groups, a + next to a layer can be clicked on to expand the group and select individual layers.
A WFS layer is plotted by the local client, so symbology can be set in your mapping application, and features on the map can be clicked on with your applications Info/Query tool to find out what values are associated with it.
A similar process should work from any WMS or WFS client application. Note that if you are accessing such servers via a web proxy or firewall, you may have problems. QGIS allows you to configure proxy settings, but firewall settings are outside the scope of a mapping tool.
Bay of Island WMS layers available from the NIWA server are:
Bay of Islands WFS layers available from the NIWA server are:
The Ocean Survey 20/20 portal has been designed for and tested against industry standard and standards compliant browsers from various vendors. Older browsers, such as Internet Exploer v6, or other browsers that do not support all of the required standards may not be able to access all of the portal's functionality.