The Spatial Miscellany


A weblog. A website. A geospatial miscellany…

Where’s my free map gone?

The Google Maps API was never meant to be free. It was an inspired accident. Clever developers reverse engineered the Google Maps site, and rather than send a cease and desist, Google published the API…more here.

The rest is history. The ‘system integrators’ day rate was slashed as the ‘mashup’ was born, and a wave of web API’s followed. The general consensus is that this is just good business sense, ‘we’d hoped advertising would have funded the API, it hasn’t, so now we need to charge some money’ – hum, I wonder if there’s more beneath the surface?

When considering this news alongside other press releases in the Google Geo space this year, like this one last week announcing GeoEyes investment in Google Earth Builder, it appears to be a deliberate shift in focus from consumer GIS to enterprise GIS. I really struggle to understand, why?

Why does an advertising & search company, who revolutionised advertising by removing the large sales force and middlemen, staff up to sell enterprise software?

Mobile Phone Development – Child’s Play

It was whilst researching HTML5 mobile phone development that I stumbled on ‘App Inventor’. App Inventor can be found in Google Labs. It’s a web based application that allows you to develop applications visually with ‘lego blocks’.

With the aim of helping children learn maths and computing, a few years back some very bright people at MIT set about building a visual programming language called Scratch. Instead of writing lines of code, you arrange lego blocks that represent events, actions and logic. For those working in the GIS space think FME or Model Builder. Google have now taken this work, and built upon it, with ‘App Inventor’. Drag and drop building blocks, from within your web browser, to build an application for your Android mobile phone – the web development environment even includes an emulator. Sounds good, but does it really work?

In short – Yes. It’s a beta service and you can only deploy to phones connected to your PC (no Android market place distribution yet). It’s a Google beta, which means comprehensive, robust, and well supported. Everything I need for my mobile apps, is already there, location awareness, read-write-web, rich user forms, local storage and graphics.

It’s remarkable that mobile phone applications can now be developed within hours. I hope Google continue to grow this initiative, and can only recommend you try it.

Faster web mapping with Google’s new browser?

Last month Google released a web browser…Google Chrome. It appears to have debuted to mixed reviews, personally I really like it, but others have had less favourable experience. On the surface, it looks much like any other web browser, but underneath, it’s a bit of an animal.

Google have acquired a new JavaScript engine (V8) written from the ground up to work more efficiently with websites that have large amounts of JavaScript rather than the little snippets of JavaScript which was typical of websites developed when JavaScript was first integrated into Netscape Navigator in the mid 1990s.

Typically JavaScript engines use a dictionary-like data structure as storage for object properties – each property access requires a dynamic lookup to resolve the property’s location in memory. V8 works differently…the first time V8 encounters an object it interprets how the object would be represented as a class, creating a hidden class, which means the next time the object is encountered, its properties can be accessed from memory without the time consuming dynamic look up.

Google give a far more comprehensive introduction to this approach in their documentation of V8, conveniently they use the example of an object common to all GIS developers…a Point.

A class based approach to JavaScript

So What?

The novel approach taken by the V8 JavaScript engine, presents a new opportunity for GIS web developers to work with Points, Lines and Polygons on the web client instead of the web server as is typical of a web based GIS. Using JavaScript in the web browser removes the need for lengthy round trips to the Server, which will make for faster web mapping applications.

Here and now, this will allow web mapping API developers to work with more markers, the typical 100 marker limit of Google Maps applications (and similar web mapping API’s) – is no more; Mike Williams and his team have reported working with as many as 2000 markers when using Google Maps within Chrome.

Chrome isn’t the only web browser to recognize the importance of working with JavaScript heavy web sites, for example, much work is being done on a new JavaScript engine for Firefox. Perhaps in the future, as this approach gains support, spatial analysis functionality can move from the server to the client, which would make for a more engaging web mapping experience?

If anyone is looking for a dissertation project, or has time of their hands, it would be interesting to see the outcome of taking some topological operators (e.g. Java Topology Suite), Google Web Toolkit (GWT) and GWT for Google Maps, all served up with Google Chrome?

Where [2.0]…are the KML files?

Last month saw the annual event that is [Where 2.0], a conference hosted by O’Reilly in San Francisco. Over the past couple of years it’s been somewhat of a landmark event in the geospatial calendar, often playing host to a raft of new and exciting location aware technology…Woodstock for Neogeography?

I’ve never managed to attend the conference, but always made a conscious effort to follow online; this year it felt different, no headline announcements or cool new products, and very little chatter.

One announcement that did grab my attention was made by John Hanke from Google during the ESRI\Google keynote (you can watch the keynote here). Hanke remarks that Google have provided access, via their search API’s, to the Google ‘GeoIndex’ – an index of results returned by Google robots as they crawl the web for geospatial content. On the surface, this is significant news, but it seems to have received only little comment.

The GeoIndex Footprint

Hanke suggests the Google search API’s will provide access to the “content, attribution, linkbacks and the urls” that make the geoweb…but where are the underlying resources, where are the KML files?

Barry Hunter has knocked up a useful php script that queries the GeoIndex and nicely formats the JSON response. Try it out and you’ll notice you get a handful of Google Maps url’s, but no links to the underlying resources? Hopefully, there is more to come; providing access to the GeoIndex, and the underlying content files, really would move the ‘geoweb’ forward.

Summer of Code & OpenLayers

Google Summer of Code (GSoC) is a program that offers student developers cash to write code for various open source projects. Google will be working with several open source, free software, and technology-related groups to identify and fund several projects over a three month period.

OSGeo and Summer of Code

I think it’s a great opportunity for students, surely better than spending many summer months obsessing on an esoteric thesis that will never see the light of day – perhaps that was just my experience? Christopher Schmidt and others have offered their support for students wishing to further develop OpenLayers, it would be great to see some of the stuff on the list tackled.

Continue Next page

Free GIS Software...

Download ArcGIS Explorer, a free geobrowser from ESRI!


Use ArcGIS Explorer to visualise geographic datasets. The latest build provides full access to Virtual Earth imagery and comprehensive support for several data formats including GeoRSS, KML and ArcGIS Layerfiles.

Before you go

Going so soon? Test your geography with the...


Do you support the campaign? Should government-funded and approved agencies such as the Ordnance Survey collect data with significant indirect contributions from the UK tax-payer, but then charge users and companies for access to it?


Download Flash plugin