By: Maxfield Barach
This document was last updated on .
In total, 708 of the 843 bomb sights from the London Fire Brigade Report found on bombsite.org were able to be located and displayed using GeoJSON and leaflet. The static image of the bomb locations with an information pop-up showing the bomb number, time and reported damage was implemented successfully. This was accomplished by creating a GeoJSON point feature collection that consists of all of the bomb sights that were able to be located. In terms of displaying the data, an Open Street Map background layer was used. An if else state was then used to assign each point a color based on what type of bomb it is representing. Finally, the map has basic interactive abilities, allowing for panning and zooming as well as clicking on a point to bring up an information window.
The second part of the project was partially implemented, but continues to have problems. The goal of the "time-lapse map" is to display points in the order and relative temporal spacing as the bombs were actually dropped. To accomplish this, the same GeoJSON feature collection was used, but with the addition of a "count" property for each point. In order to display this data an Open Street Map background layer was used, and the same if else function as the static map was used to assign points colors. In order to place one point at a time with at delay between the points, the else if statements and display commands were written into a function called displaySites(), which takes a parameter called "num". I then created a for loop in order to process the feature collection, which passes the loop variable "i" to the displaySiteS() function. In order to create the delay, the SetTimeout() function was used which called the displaySites() function and the corresponding value from the WaitTimes array, which stored the amount of time from the start of the page loading that each point needed to be delayed.
The "time-lapse map" has had the tendency to cause the browser or script to crash or become unresponsive after about 3 and half minutes of running. I think this is due to too many points being passed to browser too quickly but I have not been able to find a solution. The second map also lacks general formatting such as a title, legend and descriptions. If a more efficient method for displaying the points in the "time-lapse" map.
A possible future extension of this project could be to get time-lapse map working, as well as mapping data from more than just the first day of the blitz. More information could also be presented about the data already mapped, such as images (either modern or historic) of the areas each bomb was dropped in.