GIS help
Contents
Screen layout
The screen is divided into two sections:
1. The main map panel, with associated toolbar at the top, and status bar at the bottom.
2. A side bar on the left providing various options.
Map panel
Toolbar
The toolbar is located at the top of the map and largely controls how the mouse interacts with the map.
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Feature information: After selecting this button, click a point on the map for details about map features at that point. No details are available for aerial photos or the NZ Topo 50 map, but details are available for other layers superimposed on these. |
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Pan: After selecting this button, you may click and drag map in any direction. Various zooming options are also available: - Double click to zoom in one level. - Double right-click to zoom out one level. - By holding the shift key while you click, you may drag a box on the map. On releasing the button, the map will zoom to the zoom level that most closely matches that box. - If your mouse has a scroll wheel, you may use the wheel to zoom the map in and out. |
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Zoom in: After selecting this button, you may click on the map to zoom in one level. Or you may click and hold to draw a box on the map; on releasing the mouse button the map will zoom in to the zoom level that most closely matches that box. |
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Zoom out: After selecting this button, you may click on the map to zoom out one level. Or you may click and hold to draw a box on the map; on releasing the mouse button the map will zoom out so the full area currently displayed fills the size of box you drew. |
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Zoom previous: Click this button to return to the last map. |
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Measure length: After selecting this button, you may click on the map to draw a line. Each click adds a point to the line, and updates the length measurement in the status bar at the bottom of the map. Double click the last point to complete the line (the next click will start a new line). |
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Measure area: After selecting this button, you may click on the map to draw a polygon. Each click adds a point to the polygon, and updates the area measurement in the status bar at the bottom of the map. Double click the last point to complete the polygon (the next click will start a new area measurement). |
Zoom slider
The zoom slider is superimposed over the top left corner of the map. You may slide the grab handle up and down to zoom the map in and out.
Status bar
Appears below the map. On the left, the location of the cursor appears in NZTM2000 but you may select other coordinates from the drop down list.
The map scale appears on the right. This is only approximate as it depends on the resolution of your monitor
Length and area measurements are displayed in the middle when measurement tools are activated.
Side Panel
The side panel appears to the left of the map. You may hide or show it by clicking the << or >> symbol at the top. Alternatively you may set a specific size by dragging the border between it and the map. The side panel provides a number of options, only one of which may be displayed at a time. Select by clicking the + beside the desired option.
Layers
Shows a list of layers that may be displayed on the map. Layers are divided into two groups:
| Base layers |
One, and only one, base layer may be displayed at a time. Select by clicking the radio button beside the desired layer. |
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Overlay layers |
Any number of overlay layers may be superimposed over the chosen base layer. Select, or de-select by clicking the check box beside the layer. Layers higher up the list are rendered over those lower down the list, and may obscure features in lower layers. You may drag and drop layers within the Overlay Layers group to change the order. |
Google Satellite is in a different map projection to all the other layers, and its photos are provided at a different, coarser set of zoom levels. You may encounter glitches when switching between Google Satellite and any of the other base layers. If you do, zooming in or out a level usually fixes things.
Layers toolbar
Add: Allows additions layers to be added to the map. A popup appears with a list of layers for selection.
You may have more than one source to choose from.
Rem (remove): Removes the currently selected layer
Prop (properties): Show properties for the currently selected layer, some of which you may alter, such as transparency.
Depending on the layer, you may also be able to change the style of presentation or filter the layer to show just certain features.
Table: Displays the attribute table for the currently selected layer. Not always available.
Legend
Displays a legend for the layers currently selected. No legend is associated with aerial photos or the NZ Topo 50 layer.
Print to PDF
NOTE: this facility is not available when Google Satellite is the base layer
Prints the map to a pdf file. A print frame rectangle appears over the map to show the area that will be printed. You may drag the frame, or resize it by dragging one of the resize handles (round circles at corners and midpoints of sides).
The side panel provides the following options.
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Layout |
Choose the page format. |
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Title |
Enter a short title to be printed at the top of the map. |
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Comment |
Enter a brief comment to appear at the bottom of the map (optional). |
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Dpi |
Increasing the dpi improves the quality but, if set too high, may cause the process to fail. 300dpi is usually a good choice. |
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Scale |
Scale of the printed map. |
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Rotation |
Allows you to rotate the area to be printed. |
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Create PDF |
Once you have set your options and selected the area to print, click this button to create the pdf file. |
If you are using Internet Explorer you may need to change your settings to allow the pdf file to be downloaded. Depending on the version of Internet Explorer and your current settings you may need to:
- Allow pop-ups.
- Add this web site as a trusted site (Menu: Tools --> Internet Options--> Security tab. Click on Trusted sites, then click Sites button to add this site).
Tips and tricks for printing
For a quick, but lower quality printout, use the print facility on your internet browser. This will, of course, show everything, including toolbar and side panel. Use the PDF faciltity when you require higher quality.
Fewer labels (names of features) may appear on PDF output. This is because on the screen, each layer is rendered independently without regard to other layers, which is why features and labels on a layer may obscure those on layers below. With PDF printing, labels for all layers are rendered after all the features have been printed. If two labels overlap, the label on the lower level layer is dropped. You may be able to correct this by dragging the layers you most want labelled higher up the layer list.
Printers are cabable of showing finer detail and are legible at smaller sizes than displays on computer monitors. This creates a few issues when using Print to PDF:
Your computer monitor may not clearly show the PDF printed map unless you increase the zoom level in the PDF display to 200% or more. You need to actually print the PDF document to see what your printer is capable of.
To prevent clutter on the screen, some features or feature labels do not appear on the screen until you 'zoom in' but will often appear on a 'zoomed out' printed map. You may need to experiment:
- Select the layers to appear on the printed map.
- Zoom out until you can see the full area to print. Some detail may no longer show on the screen.
- Select Print to PDF in the sidebar.
- Drag and resize the print frame to set the area to print.
- Click Create PDF.
- If the detail does not show, try increasing Dpi. Increasing Dpi has the same effect on printed detail as zooming in, but also reduces the size of features and labels on the printed page.