Digitising Tips for December 08

The People's Map user base is growing on a daily basis as more and more people are contributing to the Peoples Map. People have different styles and methods of data capturing, but it is important that we try and keep the end product as simular as possible. It is also very important for us to collect data as accurately as possible as this reduces valuable time spent on data verification, as we would rather like to spend it on data creation and building the map.

I have therefore created this list of data capture tips that will not only assist you with creating accurate data, but will also highlight certain issue and bugs that the system is experiencing and provide you with a work around/solution for each of these.

1) Most of you must have noticed that some of the major roads positional accuracy can be off by hundreds of meters in some areas.

Cause: This data was originally captured to a scale of 1:1,000,000 and was imported into the People's Map. This means that this data is accurate when viewed on a small scale, but not when zoomed in.

Solution: These roads should be moved into the correct position by moving the red nodes of this road to the correct location. Zoom in as close as needed to place the road node as accurately as possible.

2) Sometimes, when you are moving roads, like the example above, to the correct location, a duplicate may appear. It is therefore confusing as to which road is the actual and which is the duplicate.

Cause: All moves are registerred into a database as and when a new point is created, but sometimes a delay appears with this process and a duplicate is created. Eventually the process catches up, but the original road remains as the duplicate, untill refreshed.

Solution: This problem should not occur for much longer than January next year as the new site and database structure will be implemented, but in the mean time: If a duplicate appear, whilst editing, just flick back to and from the "View" mode to "Edit" mode and this duplicate will disappear. You will notice that the new line has been captured and the original (duplicate) has been removed.

3) Sometimes when creating a road, the actual line will change to a black line, without you noticing this. When this bug occurs, the road data will become worthless to us and needs to be recreated.

Cause: We are unsure of the exact cause, but this should no longer be a problem when the new site is launched in the New Year.

Solution: Unfortunately the only existing solution is to delete this road and recreate it. If deletion is not possible, then just leave it as it is and we will clean the data appropriately afterwards.

4) Users sometimes create roads, but forget to actually connect the road created to those it is leading from or into. Good, clean geographical road data are always connected to one another.

Cause: Incorrect Data Capture Methods

Solution: The end node of a road can simply be moved to snap to the node on the road it leads from or into. If there is no node, just create one by clicking and dragging the segment.

I hope you will find these tips helpful. Please feel free to let us know of any other problems that you have experienced whilst creating data in People's Map by emailing support@peoplesmap.com.