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Defining the Projection or Projecting the Data?

Have you ever imported data that doesn’t quite line up how you’d expect? It may be that you’ve fallen victim to a common workflow error when importing GIS data. Some file types such as CSV can be used for GIS data but don’t contain coordinate system information. When you are importing data from this format, you first have to define the correct coordinate system.

In this example, we’re going to look at the common mistakes people make and how to avoid them. We’ll start with a world map in the Robinson projection.

Robinson mapWe have a CSV file containing points for large cities that we’d like to add to the map. We know from our data source that the CSV uses the WGS84 coordinate system. After selecting the file for import, the MAPublisher Import dialog box helpfully notifies us that some required settings are missing. We’ll click the blue ‘Required settings are missing’ link to continue.

required settingsSetting up the import, the coordinate column settings are easy since we have an X_COLUMN and a Y_COLUMN, but we can’t forget to check that the format is correct. The default is Projected units, but we know the file uses WGS84, and can tell by the numbers in the column that the coordinates are in decimal degrees, so we’ll change the format to reflect this information and click OK.

csv correct settingsBack at the import window, we see the message ‘Data loaded successfully’. Great! Let’s click OK and add the large cities to the map.

csv settings are okThe data has been imported but the result isn’t what we expected. The new layer has been added to a new MAP View, so let’s try dragging it into the Robinson MAP View with the world map.

import incorrectWe get a prompt saying that there isn’t any coordinate system information. We want it to be in Robinson like the rest of the map so we’re going to leave the default setting of Same as: Robinson.

coordinate system undefinedThe data has moved, but it still doesn’t look like we were expecting. Where did we go wrong here?

transformation incorrectThere are actually two places in the workflow where we could have avoided this common mistake. When we dragged the point layer into the Robinson MAP View, the pop-up dialog box prompted that a coordinate system wasn’t specified. We specified Same as: Robinson, thinking this was the correct choice, but we had already determined during import that the CSV was in WGS84. What we should have done here was to specify the coordinate system as WGS84.

missing coordinates correctThe other place where we could have avoided this error was right after setting up the CSV file for import. In MAPublisher 9.4, there’s a new button on the Import dialog box that allows you to see more detailed information about files being imported. By clicking the Advanced button in the Import dialog box, we would have noticed that there was no coordinate system specified.

advanced import windowEven here, it might have been tempting to choose Same as: Robinson to add it to the Robinson MAP View, but this would import the points exactly the same as before – all in one location in the middle of the map. Instead, what we want to do is click the blue ‘No Coordinate System Specified’ link and choose WGS84. After this is set up, we’ll click OK to add the data to the map.

correct import settingsThe data still isn’t quite right – it looks the same as when we first imported it. But again we notice that it has been imported into a new MAP View, so we’re going to drag the layer into the Robinson MAP View and see what happens.

import incorrectPerfect! By assigning the correct coordinate system to the data during import, the points have been imported correctly!

correct map with pointsMistakes during data import are common amongst GIS users, especially those who are just starting out. In the first scenario, when we imported the CSV and added the data directly to the Robinson MAP View, we thought we were telling MAPublisher that we’d like it to match up with the map. What we really did was tell MAPublisher that the data was already in the Robinson projection, even though we knew it was in WGS84. What we should have done first was to define the projection by telling MAPublisher what coordinate system the data is already using. Once MAPublisher knows what system the data is starting in, we can then ask it to project or transform the data into the coordinate system that we’d like to use.

When working with data that doesn’t have coordinate systems already defined, it is very important to follow the workflow in the correct order to avoid frustration when the data doesn’t line up as expected. Always check your sources when using data that isn’t defined, and make sure you’re assigning the correct coordinate system before performing any transformations or projections.

New in MAPublisher 8.4: Import Map Data from Web Services

MAPublisher 8.4 has an exciting new feature: importing data from web services. It is another enhancement to provide you with more options to access data.

simple import web service

You can import vector data using the Web Feature Service (WFS). It accesses web servers that deliver vector content in GML format. Similarly, you can import raster data with the Web Map Service (WMS). It accesses web servers that deliver raster content in a variety of formats.

Access the WFS and WMS directly from the Simple or Advanced Import dialog boxes. After selecting either Web Feature Service or Web Map Service from the Format drop-down list, browse for a web service and select one. Of course, you can easily add, remove and manage your favourite WFS/WMS in this dialog box.

WFS Services

After selecting and connecting to a WFS/WMS, simply select features (layers) or rasters you want to import into Adobe Illustrator. At the same time, you will have an option whether or not to save the original datasets in GML format.

WFS Services

Click the Info button available next to the Server Info at the top of the dialog box. You can see more detail information about the web server.

The server information

After importing features from the WFS/WMS, each of the features will be in a MAP layer and all the georeferencing of those selected features will be stored in the MAP View.

Imported features from Web Feature Service

New in MAPublisher 8.4: Image MAP Layer feature type for georeferenced images

MAPublisher 8.4 introduces two new related features: to import supported image formats directly from the MAPublisher Simple and Advanced Import dialog boxes and the Image MAP Layer feature type. To import a georeferenced image into the current MAPublisher 8.3 (and earlier) requires you 1) to create a new MAP Layer for an image to be placed, 2) use File > Place to place an image into the Adobe Illustrator document, and 3) to use MAPublisher Register Image to align with the vector work. With MAPublisher 8.4, these steps are streamlined and it will be much simpler to deal with georeferenced image files.

Below is the Simple Import dialog box. The new Format option, Image, is added to the drop-down list. Supported images include: PNG, JPG, TIF, GIF, JP2, PSD, PDD, and BMP.

MAPublisher 8.4: Import dialog window

The VancouverDowntown.tif file was selected from the MAPublisher Quick Start dataset. The source coordinate system of the image, “NAD 83 / UTM Zone 10N”, is automatically detected because it is a GeoTIFF and contains the georeference information of the image.

MAPublisher Simple Import: Coordinate System identified for the selected data

When the georeferenced image is imported by MAPublisher, it is stored in a new layer called “VancouverDowntown_image”. MAPublisher 8.4 introduces a new MAP Layer feature type called “Image”, a purple icon with the letter ” I “. From now on, all images should be placed on Image MAP Layers.

MAPView: New data type "IMAGE"

Remember that images placed in Adobe Illustrator using MAPublisher cannot be transformed or reprojected into another coordinate system. To transform an image from one coordinate system to another, it must be done using another software such as Geographic Imager.

MAPublisher 8.4 will be released very soon. Thanks for sending us feature requests like this one. If you have any feature requests for MAPublisher, Geographic Imager or PDF Maps, please feel free to drop us a line at support@avenza.com. We’re always happy to hear from you!

Import Geodatabase Feature Classes into Adobe Illustrator

In this post, we’ll cover how simple it is to import a geodatabase feature class into Adobe Illustrator using MAPublisher import tools enabled with the Spatial Database add-on.

Imported features

Spatial databases are optimized data repositories for spatial data storage and management. Many GIS environments use spatial databases to easily access and manage GIS data in a central location.

MAPublisher 8.2 introduces support for import of the popular ESRI single-user and multi-user Geodatabases: Personal, File and ArcSDE Geodatabases; and direct access to ArcSDE server. The MAPublisher Spatial Database importer is built on ESRI software libraries and requires a valid ESRI software and license installed on the computer (ArcGIS 9.2 and higher).

To import one, you can use either Simple Import or Advanced Import. In this scenario, we’ll use Advanced Import. When we add data, a list of Geodatabase types are located at the bottom of the Format list. We’ll be importing some feature classes from a simple geodatabase consisting of waterlines, hydrants and valves.

Add dialog box

After browsing for the geodatabase (a File geodatabase in this case), the Select Feature Classes dialog box appears. We’ll go ahead and select a few feature classes from the Landbase and Water feature sets listed.

Select Feature Classes

The Advanced Import dialog box shows the number of features being imported and the coordinate system as well as page and map anchors.

Confirm geodatabase import

The features are imported and are ready to be used in a map.

Imported features