Beginners Guide 18.104.22.168
Adding traffic patterns for OAM means drawing on top of an map image showing the traffic pattern.
At this point it is assume that JOSM is installed and configured properly for OAM - if not, follow instructions here. (TODO: link)
In order to show display an image in a separate layer of JOSM you need the PicLayer plugin. Go to Edit->Preferences and Configure available plugins tab on the left side. Select "PicLayer" plugin to install. In Preferences we also have to go to the Connection settings for the OSM server tab and check Use default OSM server URL since we have to use OSM data in order to match the scale of the map image we are going to download.
Now we need to get the an map image showing the traffic pattern. The source may differ by country:
Look up the aerodrome and save the traffic pattern map image from your web browser on your local hard disk.
In JOSM go to File -> Download from OSM and select the Slippy Map tab. Drag the map to the region of the aerodrome. If required, change the zoom level to display the aerodrome as well as the traffic patterns on the corresponding map image downloaded previously. Position the mouse close to one corner of the map, press and hold the left mouse button while moving it to the opposite corner in order to create an selection box. All traffic patterns shown on corresponding map image have to fit in this box. If you are done with selection press Download.
Make sure the Layers window is displayed (if not, go to Windows->Layers). It should display the Data layer you downloaded.
In the menu select PicLayer -> New picture layer from file... and locate the map image file you downloaded before. The map image will be displayed in the new layer. The Layers window list the image layer as well.
Select the image layer in the Layers window with the left mouse button and click on the Adjust opacity of the layer toolbar button at the bottom of the Layers window. Reduce the value from 100% to about 10% to 20% so that traffic pattern is just visible but all details from the data layer are visible too.
In the Layers window click in front of the eye of the image layer in order to switch to this layer. The check mark should be in front of this layer now. Now we have to scale the image in order to have the same scale like the OSM data layer. The scale is considered the same if the landmarks shown on the map image overlay with the corresponding nodes/ways of the data layer. In order have image as exact overlay of the data layer you may have to drag and/or scale the image. The JOSM toolbar on the left side of the main window has toolbar buttons for these actions: Choose Drag to move the picture or Drag to scale the picture in the X and Y axis. Don't use any other tool - otherwise the width-height-ratio is not preserved and the scale will be wrong!
If both layers overlap zoom in in order to let the aerodrome and its facilities fill the screen. Choose the select tool (Select, scale, move, rotate objects) to select all nodes and ways of the aerodrome and as little other nodes/ways as possible. In the menu select Edit -> Copy. Now create a third data layer by choosing File -> New Layer. Switch to the new layer by clicking in front of the eye of the new layer. The check mark should be in front of this layer now. In the menu select Edit -> Paste to insert the copied nodes/ways of the aerodrome. Several copy & paste cycles my be required until the full aerodrome is copied to the new layer. In order to make sure than no nodes/ways have be copied accidentally hide the OSM data layer by clicking its eye symbol in the Layers window. If you accidentally copied nodes not belonging to the aerodrome you can simply delete them in the new data layer by selecting them and pressing the Del button.
The time has come to add the traffic pattern: Select the Draw nodes tool in the tool bar on the left side. Click on the node representing the end of the runway. Then click on every point where the direction of the traffic pattern (as shown be the map image) changes until you set the final point on the other end of the same runway. Basically, this means, than you have extended the runway via the traffic pattern to a closed way. Therefore we have to split the traffic pattern from the runway. Choose the select tool (Select, scale, move, rotate objects) and selecting the way as well as the two points representing both ends of the runway and on the menu select Tools -> Split way. If you click on the traffic pattern now, the runway should no longer be highlighted as well.
Add the tags ...
Do the same for every traffic pattern ...