Tag Archives: Maps

A Brief History of Google Maps…and a not so Brief Video

In this long but useful presentation from 2012 Google Maps vice president Brian McClendon and colleages provide a detailed overview of the platforms evolution. Some of the key points are summarised below.

In the mid 90s Silicon Graphics developed the ‘Space-to-Your-Face’ demo to demonstrate the power of their Onyx Infinite Reality CGI workstation. In the demo the view zooms from orbit to the Matterhorn via Lake Geneva, using a combination of satellite, aerial imagery and terrain data. This is included in the Silicon Graphics showreel from 1996 which be viewed on YouTube here.

In 2001 the company Keyhole was founded as a startup providing mapping for the travel and real estate industries on the basis of a subscription model. After achieving wider recognition through use by CNN during the invasion of Iraq in 2003, the company was subsequently acquired by Google in 2004.

At the same time Google were working on the creation of Google Maps which used a combination of client side processing via AJAX and pre-rendered map tiles to enable its highly interactive and smooth scrolling slippy map system. However, now that network bandwidth and processing power has been increased Google Map tiles are no longer pre-rendered and are instead provided on demand.

Between 2005 and 2008 Google Maps licensed further data to obtain a full world map with more comprehensive coverage. At the same time Google were also working to acquire high resolution imagery.

Street View started in five US cities in 2007 but had expanded to 3000 cities in 39 countries by 2012. In 2008 Google released Map Maker to capture data where other basic mapping data and Street View were absent.

Google’s Ground Truth project now enables them to generate their own maps from raw data by combining satellite and aerial imagery with road data and information capture via Street View. This data is processed with an application callled ‘Atlas’ that Google developed internally. With the aid of advanced computer vision techniques they are able to detect and correct errors and extract further contextual information from the raw imagery data that helps them make their maps more complete and accurate. This includes details as specific as the names of streets and businesses appearing on signs.

Corrections are also crowd-sourced from users with the aid of their ‘Report Maps Issue’ feature. Staff at Google are then able to verify the issue with Street View, edit the map and publish the corrections within minutes.

The presentation moves on to further discussions on ‘Google Maps For Good’ and their work with NGOs (19:20), ‘Google Maps for Mobile’ and the provision of offline map availability (27:35), the evolution of the equipment used to capture Street View (31:30), and finally the evolution of their 3D technology (37:40). The final discussion in particular reiterates the content in my post yesterday from a slightly different perspective.

What I found particularly interesting in this video was the continued manual intervention via Atlas but also the extent to which they are able to gather contextual information from Street View imagery.

CleanSpace: Mapping Air Pollution in London

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Today I received a personal air quality sensor, the CleanSpace sensor tag. The device is a carbon monoxide (CO) sensor which is designed to be carried by the user and paired with the CleanSpace Android or iOS app via blueetooth. While the sensor takes readings the app provides real time feedback to the user on local air quality. It also pushes the anonymised sensor readings to a cloud server which aggregates them to create a map of air quality in London.

As well as providing data for analytics the app is intended to encourage behaviour change. It does this by rewarding users with ‘CleanMiles’ for every journey made on foot or by bike. The clean miles can then be exchanged for rewards with CleanSpace partner companies and retailers.

Another interesting aspect of the project is that the sensor tag is powered using Drayson Technologies’ Freevolt. This enables the device to harvest radio frequency (RF) energy from wireless and broadcast networks including 3G, 4G and WiFi. In theory this means that the device can operate continually without needing to have its batteries recharged because it can draw energy directly from its environment. In this way the CleanSpace tag provides a perfect test bed for Drayson’s method of powering Low Energy IoT devices.

The project kicked off with a campaign on Crowdfunder last autumn which raised £103,136 in 28 days. The campaign was initiated shortly after the announcement of results from a study at Kings College which found that nearly 9,500 deaths per year could be attributed to air pollution. Two pollutants in particular were found to be responsible: fine PM2.5 particles in the air from vehicle exhaust along with toxic Nitrogen Dioxide (NO2) gas released through the combustion of diesel fuel on city streets. While the CleanSpace tag does not measure PM2.5 or NO directly it is believed that recorded levels of CO can provide a suitable surrogate for other forms of air pollution given their shared source in car fuel emissions.

While the UK government are under pressure to clean up air pollution from the top-down, Lord Drayson who leads the CleanSpace project argues that there is also need for a complementary response from the bottom up:

“I think the effect of air pollution is still relatively underappreciated and there is work to do in raising awareness of the impact it has.”

“Yes, the government has a role to play, but this isn’t solely a government issue to tackle. The best way to achieve change, and for legislation and regulation to work, is for it to grow from and reflect the beliefs and behaviours of the general public as a whole.”

I’m looking forward to seeing what the device reveals about my own exposure to air pollution on my daily commute. It’ll also be interesting to see how my contribution fits in with the broader map being built up by the CleanSpace user community. After collecting some data I’m keen to compare the apps output with the data collected by the London Air Quality Network based at King’s College.

I’m a card carrying walker. At the same time I’m struck by the paradox that every CleanMile walked or cycled is essentially a dirty mile for the user. I can see the device and app appealing massively to those who already walk and cycle, and want to contribute to raising awareness on the issue of air pollution. However, with the sensor retailing at £49.99 the CleanMile rewards will have to be sufficiently compelling to encourage a wider base of new users participate, especially if the project is expected to have a genuine impact on the way they commute. Of course, it has to start somewhere! It’s an exciting challenge so I’m looking forward to seeing how it goes.

Google Earth Pro is Free to Download

I recent learned via the Google Earth Blog that Google Earth Pro is now free to download. I hadn’t used Google Earth for some time so I decided to try out the Movie Maker feature which is Pro only.

With movie maker it is possible to record live navigation with the mouse although this doesn’t tend to give a very smooth or or professional result. Using a specially designed 3D mouse such as the Space Navigator works much better. For my test I opted to make my video from a quick tour I created zooming into the Tower of London from orbit. This was achieved by selecting a sequence of points for the camera to visit. Movie Maker was then used to convert that tour to video. This took about 30mins to render with a fade in and fade out added in Adobe Premiere.

The attribution details at the bottom of the screen can be a little distracting because they change as the view moves between imagery from different satellites. It would be possible to crop these out but Google do insist on particular guidelines for permission to use their imagery and attribution. The are also occasional issues where parts of the 3D geometry flicker due to caching. Nevertheless, the results are very good for a quick and easy visualisation!

The combination of satellite imagery and 3D geometry are great for engaging viewers and giving a map context. Other features like a recorded voice over and the ability to highlight areas of interest can also be useful depending on the context. A comparison of features between the free and Pro versions of Google Earth can be found here, along with the link to download it.