Overlay Webmaps Development Preview – Greater Christchurch [2]

Last time we talked about the process of developing a preview for Greater Christchurch and it was hoped we could have it ready in a few days. Now we are a week into this process and although good progress has been made on this task, it’s been necessary to juggle whether to spend time getting the preview reasonably correct before publishing, or just push it out and fix the mistakes later. This meant inevitably the timetable being pushed out.

The conclusion so far has been to fix as many issues as can be reasonably achieved within a capped time frame, and although that time frame keeps getting pushed out, it is only a few days at a time. So far the deadline for completing the map data is now at the end of October, from which it is probably about another three days to a week to prepare all the layers for uploading, and create the custom home page Javascript code to display them.

As usual, the most time consuming aspect is to fix various aerial photo layers, and so far this has been performed in Heathcote, Hornby-Lincoln, Christchurch-Addington and Middleton-Sockburn. As this is written, we have the complete set of aerial coverage for Middleton that have been corrected and have just finished drawing the 1967 layout of Middleton. From there, checking the other generations available at usable resolution (1961, 1975 and 1984 in this case) for changes (which are mainly expected to be in private sidings) follows. Then after that, repeating that process for Sockburn, where the reference generation is 1980, with 1961, 1972-75 and 1984 also being available.

After that it is on to Hornby and Islington which may require more mosaic work. By the time we have finished to Islington, it might be time to decide whether to just create the preview at that point, with only the MSL from Lyttelton to Islington completed (around 20 km) completed, and then add other GC coverage later. It is reasonably certain that it could take weeks to add all of GC and that pushes too much into the planned timetable for other maps previously planned. So completing GC on just a part of the MSL that is within Christchurch City, is the most likely scenario for the preview for the purposes that we want to use it for at the moment.