World Wind Project - Montreal Now and Then
Comparing Montreal's Current Metro System to the Rail Transit Available in 1903
The goal of this project was to use a georectified image of Montreal in 1903 in World Wind to compare public transit opportunities then and now. Georectification was done in ArcGIS. A jpg was created there and loaded into World Wind after an xml file with its lat/lng coordinates was created. To compare the transit system then with the current system, I have loaded a set of icons at the locations of each of the Metro stations into World Wind by creating an xml file that loads the layer during configuration.
To do this project, I've Georectified an image of Montreal in 1903 taken from the following website: www.mcgill.ca/files/gic/rectify9.pdf This image tells us where the rail transit was in 1903. My project will compare the location of transit lines then and now in the city.
General Observations:
Though it's not rigorous or very precise, there are some general observations that can be made from my study. The Metro extends in fewer directions with fewer lines, stops, and opportunities for boarding and disembarking, but it extends farther and reaches to greater distances from the city center than the tram system of 1903. We can see the higher downtown density of the 1903 tram especially with the following snapshots from World Wind (the blue icons are Metro stations, the dark black dashed lines on the colored image are tram lines) .
This difference is probably because population was more centralized in 1903, and the transit system being built to serve the highest numbers of people concentrated its service downtown. Yet, one might argue that had the tram been faster and more efficient, it would have allowed people to live at greater distances from the city center as they now do. The other thing to keep in mind is that many of the lines present in 1903 may currently be covered by bus routes that carry similar amounts of traffic. This is something I was not able to account for in my study.
Other images below show the great distance the current Metro system reaches in comparison with the 1903 map. The conclusion that the Metro system reaches farther is not completely valid, because the georectified image did not show the ends of the lines, but it does at least give a clue that they did not go much farther because the number of lines diminish greatly at the edges of the images. The comparison here clearly shows that the 1903 tram system was greater in density and number of lines downtown than the Metro is, and gives us room to guess that the Metro lines stretch further out than the tram service did.
Technical things I learned:
To bring a georectified image from ArcGIS into World Wind, you have to get the map framed in your viewer just the way you want to see it in World Wind, go to File-Export Map. Choose jpg or some other format but make sure the resolution is high enough that you can see what you're looking for in World Wind (in my case, it was the rail transit lines). Then, to write the xml file that will load the image, you have to have the east, west, north and south latitude and longitude coordinates. To get those, leave the viewer as it is; go to Spatial Analyst-Options, and choose the Extent tab. Then for Analysis Extent choose Same as Display. The coordinates shown are the ones used in the xml file.
To create and load lines in the boundary format, you must learn to write binary files. I spent a lot of time trying to create and use these files, as I was able to get points from a http://www.dashmaps.com/montreal/googlemaps site which draws the Metro lines in xml. I tried to use this data to create the necessary files for display of this data in World Wind. The instructions on World WInd's Wiki are vague, and using the forum only helped me to identify that I did not know how to write a binary file. So, I was unsuccessful in using the dashmaps lines to create lines for use in World Wind.
In creating icon xml files for World Wind, the description text cannot begin with numbers. I tried to load the addresses into the description, but the file had an error because the text began with numbers.
The xml file will not load if you use accents in your text.