Data Distribution Application (DDA)

About DDA

DDA is intended primarily for converting the Data & Maps vector data from Smart Data Compression (SDC) format to shapefile format. The SDC data can first be viewed in the DDA viewer by opening the provided ArcGIS map document (mxd) or AXL files, or by adding in the individual SDC files. After panning and zooming to the area of interest, all data layers checked on in the table of contents can then be extracted to shapefiles for the current map extent.

There are two versions of the application: DDA_Arc.exe for users with ArcGIS installed, and DDA.exe for users without ArcGIS installed.

How to convert Data & Maps SDC files to shapefiles using DDA.exe

1. In Windows Explorer, double-click on DDA.exe. This will open the DDA window.

2. To add Data & Maps SDC data to DDA for one of the geographic areas (United States, World, Europe, North America, or Mexico), click the Open button and browse to the desired folder. Select an axl file and click Open. This will open a map in the DDA window, with all of the available layers listed in the table of contents at the left. The initial extent of the map will be the total extent of all layers included in the axl file. The map may also appear curved, since some of the axl files use projections that are centered on the selected geographic area. If necessary, use the Zoom and Pan tools to zoom into the area of interest.

Notes:

· Depending on how far you are zoomed in, you may or may not see a layer displayed in the map even though it is checked on in the table of contents. This is because there can be a scale range setting for each layer, and the scale of the map is not within the range.

· You can alternatively add individual SDC files to DDA one at a time by clicking the Add Data button and browsing to the files.

· Some DVD drives may have a problem opening the StreetMap North America.axl directly from the DVD. If opening this axl from the DVD causes DDA to hang, then you should copy the entire \streetmap_na folder to your hard drive and open the axl from your hard drive. This will require about 5.1 GB of disk space.

3. Determine which layers you wish to extract by clicking on or off the layer check boxes in the table of contents. Each layer checked on will be extracted as long as there are features for the layer within the selected extent. This is true even if the layer is not being displayed because the map scale is outside of the range setting for that layer.

Note:

· Depending on the extraction extent and which layers you have turned on, some extractions may take a long time and create rather large shapefiles. If a layer checked on is not being displayed, you should consider what type of layer it is and the amount of features that could potentially fall within the extraction extent.

IMPORTANT – In the StreetMap North America.axl, the Detailed Streets layer contains all streets within North America. If you wish to turn on this layer and extract the streets, your extraction extent should be limited to a few states or provinces at the most, depending on the size of the states or provinces and how populated the area is. It is impossible to extract the streets for the entire North America region, as it will exceed the file size limits of a shapefile.

4. Determine the extraction area using one of these three methods:

1. Map Extent – Use the Pan and Zoom tools to set the map extent defining the area to be extracted. During extraction, all features within the viewable extent will be clipped to that extent.
2. Selected Features –Select features from one of the area (polygon) layers by first choosing the layer from the “Select by features from:” pull-down list. Note that only layers with area features will be listed. Then use the Select Features tool to select features from the chosen layer by either dragging a box or clicking on the feature. Hold down the Shift key while clicking if you wish to click on more than one feature. You can choose a layer and select features even though the layer is not displayed in the map, but it must be checked on in the table of contents. After your selection, the selected features will be highlighted, even if they were previously not being displayed. During extraction, all features falling within the boundaries of the selected features will be clipped to those boundaries.
3. Draw Graphic – Use the Draw Rectangle or Draw Polygon tool to draw a graphic defining the area to be extracted. When drawing a rectangle, click and drag a box, and then let go. When drawing a polygon, click to define the vertices of the polygon, and then double-click on the last vertex. During extraction, all features falling within the boundary of the rectangle or polygon will be clipped to the boundary. Please note that you can only define one graphic for this extraction method.

5. Click the Extract Data button. The Extraction options dialog will appear.
6. In the “Select extraction boundaries” section, select the desired option. If you do not have any selected features or a graphic, those options will be grayed out and inaccessible.
7. In the “Select output format” section, select the ESRI Shapefile option, which is checked by default.
8. In the “File name properties” section, enter a prefix and/or suffix if desired. If both of these boxes are left blank, the shapefile will have the same name as the source SDC file, except with the .shp extension.

Note:

· There may be cases in an axl where there can be two different data sources in different folders using the same SDC file name. For instance, the Mexico Map.axl file uses an admin.sdc from the \background folder and an admin.sdc file from the \data folder. Since both files must be extracted to the same output folder, the first one extracted will be named admin.shp and the second will be named admin1.shp.

9. In the “Select output directory” section, either type the path to the desired output folder, or click the browse button and browse to the location. If the folder does not exist, you will be prompted to create it. All output files from the extraction process will be stored in this folder.
10. Click Extract to begin extracting all layers checked on in the table of contents that fall within the defined extraction extent.

Notes:

· There can be multiple layers within an axl file that use the same SDC source file. However, even if more than one layer using the same SDC file is checked on, only one shapefile will be output.

· Metadata (.xml files) for all extracted shapefiles (except for the background layers) will also be copied to the output folder. Detailed information about each dataset is stored in this metadata file, and it is based on the full extent of the source SDC file. Although you need ArcGIS to view the metadata in a structured format, you can still see all of the information by double-clicking on the .xml file in Windows Explorer, which should open the file using your default web browser.

· In addition to the shapefiles, an extracted.axl file is also created in the output folder. This axl can immediately be opened in DDA, where you can see all of the new shapefiles clipped to the extraction extent. All of the symbology and labeling is carried over from the original axl file, as well as the map projection (if any) and the layer scale range settings. This axl file can also be used in ArcIMS Route Server to create an image service, although it will not support routing or geocoding. You may need to modify the SDCWORKSPACE tag in the axl file to point to the correct data location.

How to convert Data & Maps SDC files to shapefiles using DDA_Arc.exe

1. In Windows Explorer, double-click on DDA_Arc.exe. This will open the DDA_Arc window.

2. To add Data & Maps SDC data to DDA_Arc for one of the geographic areas (United States, World, Europe, North America, or Mexico), click the Open button and browse to the desired folder. Select an ArcGIS map document (mxd) file and click Open. This will open a map in the DDA_Arc window, appearing exactly the same as if it were opened in ArcMap, with the correct map extent and projection. All of the layers and group layers appear in the table of contents at the left with the same symbolization. If necessary, use the Zoom and Pan tools to zoom into the area of interest.

Notes:

· Depending on how far you are zoomed in, you may or may not see a layer displayed in the map even though it is checked on in the table of contents. This is because there can be a scale range setting for each layer, and the scale of the map is not within the range. In these cases, the check next to the layer will be grayed out.

· You can alternatively add individual SDC files to DDA_Arc one at a time by clicking the Add Data button and browsing to the files.

3. Determine which layers you wish to extract by clicking on or off the layer and group layer check boxes in the table of contents. Each layer checked on will be extracted as long as there are features for the layer within the selected extent. This is true even if the check is grayed out and the layer is not being displayed. In addition, if a checked layer is part of a group layer, the group layer must also be checked on in order for the layer to be extracted.

Note:

· Depending on the extraction extent and which layers you have turned on, some extractions may take a long time and create rather large shapefiles. If a layer checked on is not being displayed, you should consider what type of layer it is and the amount of features that could potentially fall within the extraction extent.

IMPORTANT – In the StreetMap North America.axl, the Detailed Streets layer contains all streets within North America. If you wish to turn on this layer and extract the streets, your extraction extent should be limited to a few states or provinces at the most, depending on the size of the states or provinces and how populated the area is. It is impossible to extract the streets for the entire North America region, as it will exceed the file size limits of a shapefile.

4. Determine the extraction area using one of these three methods:

1. Map Extent – Use the Pan and Zoom tools to set the map extent defining the area to be extracted. During extraction, all features within the viewable extent will be clipped to that extent.
2. Selected Features –Select features from one of the area (polygon) layers by first choosing the layer from the “Select by features from:” pull-down list. Note that only layers with area features will be listed. Then use the Select Features tool to select features from the chosen layer by either dragging a box or clicking on the feature. Hold down the Shift key while clicking if you wish to click on more than one feature. You can only select features from a layer that is displayed in the map, so make sure you have chosen the correct layer name from the list. After your selection, the selected features will be highlighted. During extraction, all features falling within the boundaries of the selected features will be clipped to those boundaries.
3. Draw Graphic – Use the Draw Rectangle or Draw Polygon tool to draw a graphic defining the area to be extracted. When drawing a rectangle, click and drag a box, and then let go. When drawing a polygon, click to define the vertices of the polygon, and then double-click on the last vertex. During extraction, all features falling within the boundary of the rectangle or polygon will be clipped to the boundary. Please note that you can only define one graphic for this extraction method.

5. Click the Extract Data button. The Extraction options dialog will appear.
6. In the “Select extraction boundaries” section, select the desired option. If you do not have any selected features or a graphic, those options will be grayed out and inaccessible.
7. In the “Select output format” section, select the ESRI Shapefile option, which is checked by default.
8. In the “File name properties” section, enter a prefix and/or suffix if desired. If both of these boxes are left blank, the shapefile will have the same name as the source SDC file, except with the .shp extension.

Note:

· There may be cases in an mxd where there can be two different data sources in different folders using the same SDC file name. For instance, the Mexico Map.mxd file uses an admin.sdc from the \background folder and an admin.sdc file from the \data folder. Since both files must be extracted to the same output folder, the first one extracted will be named admin.shp and the second will be named admin1.shp.

9. In the “Select output directory” section, either type the path to the desired output folder, or click the browse button and browse to the location. If the folder does not exist, you will be prompted to create it. All output files from the extraction process will be stored in this folder.
10. Click Extract to begin extracting all layers checked on in the table of contents that fall within the defined extraction extent.

Notes:

· There can be multiple layers within an mxd that use the same SDC source file. However, even if more than one layer using the same SDC file is checked on, only one shapefile will be output.

· Definition queries set in the Properties for a layer in an mxd are ignored during extractions. The output shapefile will contain all features from the source SDC file.

· Metadata (.xml files) for all extracted shapefiles (except for the background layers) will also be copied to the output folder. Detailed information about each dataset is stored in this metadata file, and it is based on the full extent of the source SDC file. To view the metadata, browse to and click on the shapefile in ArcCatalog, then click the Metadata tab. You can view the metadata in different formats by changing the Stylesheet type at the top left of the ArcCatalog window.

· All Data & Maps ArcGIS layer (.lyr) files associated with the extracted shapefiles will also get copied into the output folder. These lyr files store symbols and classifications for the shapefiles when used in ArcGIS.

· In addition to the shapefiles, a new mxd is also created in the output folder. This mxd can be opened in DDA_Arc or ArcMap, where you can see all of the new shapefiles clipped to the extraction extent. All of the symbology and labeling is carried over from the original mxd, as well as any group layers, map projection (if any), and layer scale range settings.

· Along with the new mxd, a new axl file is also created. This axl file can be used in ArcIMS Route Server to create an image service, although it will not support routing or geocoding. You may need to modify the SDCWORKSPACE tag in the axl file to point to the correct data location.