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GIS+

Canvas GIS+ has various GIS-based tools and commands that allow you to work with various GIS formats, define a map projection, and perform advanced property operations. GIS (Geographic Information System) information can be used in a variety of fields such as engineering, resource management, public utility management, business, town planning, etc.

Creating a New GIS Document

To create a new GIS document:

  1. Choose File | New.
  2. In the New Document dialog box, select the GIS Document check box.
  3. Select other New Document settings as appropriate.
  4. Click OK. A new document opens and the GIS manager is displayed.

GIS manager

The GIS Manager lets you select or define geo-referencing information for a document. In addition, you can use the GIS manager to re-project the projection of a document that is currently open.

To open the GIS Manager:

Choose GIS | GIS Document Settings.

GIS manager

If you are currently working in a GIS document, the scale and projection settings will be indicated. If not, you can select the check box to Enable GIS.

Enable GIS

Select this check box to access the Projected Coordinate System options.

Document

Lists the document scale and coordinates for the top, bottom, left and right.

Projection

Select the projection.

Select: Click Select to open the Select Map Projection dialog box, which contains predefined projections. Select one from the list. The related property and parameter values are displayed on the right.

Edit: Click the Edit button to open the Map Projection dialog box. Select a projection from the list. Further customize the projection by entering the necessary values in the Parameters section.

Geo CS

Select the earth model. The default earth model is WGS 1984.

Select: Click Select to open the Select Geographic Coordinate System dialog box. Select one from the list. The related property and parameter values are displayed on the right.

Edit: Click Edit to open the Geographic Coordinate System dialog box (see Edit Geographic Coordinate System dialog box).

Angular Units

Select the units that you want to use in the projection.

Linear Units

This unit of measure corresponds to your document unit in a GIS-enabled document.

Axis Orientation

Select either North East, North West, South East, or South West as the Canvas 0,0 origin.

Auto Define

Click Auto Define to open the Auto Define Document Coordinate System dialog box (see Auto Define Document Coordinate System).

Select

Click Select to open the Projected Coordinate Reference Systems dialog box. Choose one from the list and click OK.

Save

Click Save to save the current projection in a PRJ file.

Load

Click Load to open a saved projection in PRJ or TXT format.

Edit Geographic Coordinate System dialog box

Use this dialog box to define a geographic coordinate system for the projection.

To open the Edit Geographic Coordinate System dialog box:

In the GIS manager, in the Geo CS section, click the Edit button.

Geo CS Name

Enter a name in this field.

Load

Click Load to open a saved Geographic Coordinate System in PRJ format.

Save

Click Save to save the current Geographic Coordinate System in a PRJ file.

Datum

Ellipsoid (meter): Select a defined ellipsoid from the menu. If you select Custom, you have to define the other elements in this section.

  • Semi-Major Axis: Half the distance across an ellipse along the longest of the principal axes.
  • Semi-Minor Axis: Half the distance across an ellipse along the short principal axis.
  • Flattening: The ratio of the length of half the semi-minor axis of the ellipse to half the semi-major axis of the ellipse, subtracted from 1.
  • Inverse flattening: Calculated as the length of the semi-major axis over the difference in lengths of the semi-major and semi-minor axes.
  • Eccentricity: Calculated value for the first eccentricity.
  • Second Eccentricity: Calculated value for the second eccentricity.

Prime Meridian: Select an option from the menu. The prime meridian forms the origin for the longitude part of the geographic coordinates and divides the eastern and western hemispheres.

Datum Transformation

Select an option from the Transform method menu.

If you select None, no transformation is performed. If you select, Geocentric translations, you have to define the Shifts to WGS 84. If you select Coordinate Frame rotation or Position Vector 7, you have to define the sections for Shifts to WGS 84, Rotation to WGS 84, and Scale Correction to WGS84.

Auto Define Document Coordinate System

Use this dialog box to set your drawing scale, establish a reference point, and define a reference rectangle. Based on the selected point or defined bounding box, Canvas sets up the projected coordinate system for the file.

To open the Auto Define Document Coordinate System dialog box:

In the GIS manager,click the Auto Define button.

Reference Point

Allows you to define a scale and reference point within the document.

  • Scale: Enter a scale amount in this field, if necessary.
  • Latitude/Longitude: Select an anchor point and then enter the coordinates for the reference point.

Reference Rectangle

Enter coordinates to establish a bounding rectangle for the document. The rectangle is defined by the minimum and maximum coordinates in each of the two directions.

GIS Positioning palette

You can use the GIS Positioning palette to strategically move or position objects according to their latitude and longitude coordinates. The GIS Positioning palette also displays Length and Forward Azimuth when measuring between two points.

When expanded, the percentage of error is indicated at the bottom of the palette. The distortion percentage is calculated by comparing the document’s reference point (document center) to the world.

To open the GIS Positioning palette:

Choose GIS | GIS Positioning.

To measure distance in world coordinates:

  1. Create a line between the two points to be measured.
  2. Select the line and open the GIS Positioning palette. The Length and Forward Azimuth are indicated.

To position objects with the GIS palette:

  1. Select the object to be positioned. The object’s current coordinates appear in the Latitude and Longitude fields at the top of the palette.
  2. Select a handle in the bounding box icon and then enter the new latitude and longitude values. The object moves to the defined coordinates.

    3. The coordinates are based on the object’s selected handle. By default, the center handle is the reference point when the object is first selected (see To manually position the center reference point:).

Positioning replicates

If you have to create several replicates of an object and then place each of them according to their latitude and longitude, the Replicate and Position abilities will be of benefit to you (see Replicating and positioning options).

The GIS component of the Replicate and Position dialog box is enabled once you have configured the GIS settings with the GIS manager (see GIS manager).

To use the Replicate and Position dialog box:

  1. Select the object to be replicated.
  2. Choose Edit | Replicate and Position.
  3. Click the Angular radio button.
  4. Enter the latitude and longitude coordinates for each replicate. You can load or paste coordinates.
  5. Click OK to create and position the replicates.

To manually position the center reference point:

  1. Select the object and click once more. The object’s handles appear.
  2. Move the cursor over the center reference point. The cursor changes to a crosshair.
  3. Click the crosshair on the selected handle and move the handle to another position. The object’s latitude and longitude update after you release the cursor.

Choosing a reference point

This command allows you to set the origin of your document. You also have the option of preserving the objects’ coordinates, which can be viewed as a “move paper sheet” command.

To define a reference point:

  1. Choose GIS | Choose Reference Point. A prompt appears when you move the cursor into the drawing area.
  2. Click the cursor to define the new origin.
  3. In the GIS Reference Point dialog box, select one or more of the following:

Creating a graticule

Use the Graticule settings dialog box to create a grid of lines that display meridians of longitude and parallels of latitude.

To open the Graticule settings dialog box:

Choose GIS | Create Graticule.

Drop-down list

Select either Use Document Bounds, Use Selection Bounds, or Custom from the menu. If no objects are selected, the Use Selection Bounds option is disabled.

For Custom, you must enter values in the Start and End sections for both Latitude and Longitude.

Unit

Select a unit from the menu. Document unit changes to this unit. You can choose angular units or linear units.

Precision

You can choose from no decimals to six decimals, or even use fractions.

Longitude

If a linear unit is selected, this section is labeled Easting.

Start/End

Enter the values that the meridians should span.

Spacing/Divisions

These two values influence each other. The larger number of divisions, the smaller the spacing becomes. Conversely, if you enter a large value for the spacing, the number of divisions decreases.

Latitude

If a linear unit is selected, this section is labeled Northing.

Start/End

Enter the values that the parallels should span.

Spacing/Divisions

These two values influence each other. The larger number of divisions, the smaller the spacing becomes. Conversely, if you enter a large value for the spacing, the number of divisions decreases.

Labels

You can define the settings for the labels. Select the font type and size.

Latitude Rotate 90 deg

This option rotates the labels for the parallels (latitude) at a 90 degree angle.

Frame With Ticks

This option produces short lines indicating where selected meridians and parallels intersect. If selected, a full grid is not created, only tick marks.

Horizontal Offset

This setting affects the placement of the labels for the meridians (longitude).

Vertical Offset

This setting affects the placement of the labels for the parallels (latitude).