Thursday, 31 August 2017

Nelson Section [8]: Maps released

As I'm a bit too busy to pump out posts about the Nelson Line in general I have just published two Flickr albums with each containing a full set of maps of the line.

The maps are arranged so that they always present the route from left to right, this ensures it is very intuitive when you scroll from one tile to the next. This is achieved by constantly rotating the design view of every individual tile before it is produced. So in the previous maps where the limitation was that the top was always north, the rotation means that the direction of North is set individually for every single map, and indicated by a small arrow indicator in the bottom left corner. 

Another improvement is to show a scale bar rather than a meaningless numerical ratio measurement, this means you can measure off the scale with a ruler.

Distances as mentioned in a previous post can either be kilometres or decimal miles and you will see actual miles shown where the imperial measurement was established prior to metrication and not superseded by a metric measurement. On the Nelson line in particular the line was closed well before metrication so the imperial measurements are entirely appropriate. The scalebar is always metric however.

The idea of aerial overlays is they are maps overlaid on the current Linz aerial photos of an area. This album contains 80 tiles from Nelson to Inangahua. These are suitable for PC viewing.

These are just the basic maps without aerial photo topography, instead they have terrain relief shading imagery from Linz Data Service that helps to show the rise and fall in the terrain. They are eminently suitable for viewing on a phone or other mobile device, also ideal for individual printing out on a regular monochrome printer. 83 tiles (these tiles are smaller than the aerial tiles above which accounts for the increased number).

In addition a folder of aerial photos has been released:  Nelson Aerial Sources
Most of these tiles are from Linz, there are four from National Library which are sections of a streetmap of Nelson.

A map volume is also being assembled at present for Nelson. Since I am at this stage producing just a single volume purely for Nelson I will have to look at the relevance of my previous volume number system to see whether there was a volume number for Nelson on its own. This will be a trial of the new volume format which uses maps that are highly optimised for space efficiency by using the rotational technique mentioned above. At this stage I expect a completed volume for this particular line will have around 33 pages. This is a significant reduction from previous predictions of map volume size and will be the system used to generate all the volumes that are produced.

Finally I am investigating whether I can put my data into Open Street Maps. If it does get agreed to then the data will just be the corridors and stations. Not all of the data I have in the maps will be useful or wanted for OSM and converting some of the data to their formats would take too long. There are also possible issues with generations of data in OSM - it doesn't have the ability (as far as I know) to show different versions of maps the way I can do in Qgis with the filter feature on a layer.