Submitted: Thursday, Apr 24, 2008 at 19:35

For most of this week I have been locked into the mapping system on ExplorOz and have made significant improvements currently only shown in the places system. For those that did not know I have added the OpenLayers (open source) mapping product interface into the iMapPlot systems. This allows us to show any kind of base map data we like and currently we are showing Topo 250 and a load of Google maps (Satellite, streets etc). There are hundreds of providers out there however this is the current selection.

Once I decided on OpenLayers and trying to project our data on Google base maps I came across the first of many hurdles map projection. Google uses it's own projection codes and if you want to display data on any Google maps then you must utilise the Spherical Mercator projection (round earth) for all data to be shown. Thus I had to modify the MapServer system to use GDA94 data and projected it in EPSG:900913 - Not a difficult task to do however it does take some time to get it all clear in your head. Once I had re-projected the topo 250 data I had on the server I decided it was time to update to the latest Geodata Topo 250K base that is available.

This took 4 days to import and to build the shape tiles. I then also decided it worth adding some additional data layers and doing a full round of scale testing. What a job - I have seen so many maps over the last few days that I am well over it. So basically the latest round of places maps (shown in a specific place not the index) are using the most up to data Topo data available and using what we believe is the best scales, colours, symbols and labels that we can deliver.

I also added a 256 colour palette to the MapServer system to ensure the tiles are as small as possible for speedy download. Our map tile download speed is within milliseconds of Google at present so this is a really good improvement.

There is also available in the new interface a legend control (link near the bottom right hand corner of the map) that will allow you to open up the map legend for the Topo 250 maps.

There are also a number of controls in the mapping window and a help system will be loaded soon to explain some however quickly:
Double left click - zoom in (centred on mouse click)
Shift Key + left mouse button + mouse move - allows you to zoom on the map
Of course you can change the base maps and add layers using the layer control, you can also hide this control, click on the little box at the top right hand side of the control.

Of course this new technology will make it's way to the rest of the system in due course. In fact it is also available in the directory system, we have geo-coded the advertisers database and have built dynamic maps for each business and linked them directly to the driving directions system.

I really hope you enjoy our new mapping system interfaces and as always please send in your feedback or requests and we will endeavor to implement as much as we can.

Anyway time to get out of the office. Have a great ANZAC day and weekend.

Tags: Site Development, Work
Views: 423

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