Sunday, March 30, 2014

Cloud free base map image from MapBox

Cloud free, near real time, seamlessly integrated scenes of imagery acquired by various satellites orbiting the Earth is a holy grail of remote sensing community. However, achieving this result is not a trivial task due to volume of data and computational capacity required to process it. So, for now, we only have one-off attempts to create such mosaic with lower resolution imagery.

You may be well familiar with Blue Marble seasonal mosaics of MODIS imagery (~500m resolution) that appeared on many versions of online maps but the latest version created by MapBox is a great improvement on the previous, dated by now version, which deserve a mention.

The goal was to make the most beautiful image of an idealized, cloudless planet, “trapped in eternal summer”. As described by the creator, “It’s a completely natural product. Every pixel is a real pixel captured by a camera in the sky. But it’s also completely synthetic.”

You can preview the entire globe of cloud free imagery on MapBox’s tour page and the whole process of generating that image was well explained in Wired article in 2013.

Now the race is on to produce a higher resolution version (possibly based on Landsat 7 and Landsat 8 data) as well as to utilise all the possible band combinations to extract information, in near-real time, on glaciers, wildfires, crops, droughts and floods, cities and forests, surface temperature, plankton blooms, seasonal dynamics, smog, and myriad of other earth surface, near surface and shallow water objects. And most importantly – observe changes over time.

It is interesting to note that, yet again, innovation is driven by a relative newcomer to the spatial industry. As I pointed out in my 2013 end of year reflection, this is a very common pattern in the last couple of decades, where “old hands” just can’t recognise all the opportunities that technological advancement and computational capacity bring to this industry, and it takes outsiders to “spot the obvious”.

MapBox is definitely one of the more innovative companies that emerged in recent years and is worth watching - we can all learn from their fresh approach to old problems…

Related Posts:
New approach to satellite imagery analysis
Landsat 8 data explained
Google unlocks Landsat archives
Free high resolution imagery

Thursday, March 27, 2014

San Francisco crime map

The ability to filter results according to user preferences, to bring meaning to complex information, is an indispensable functionality of any great data analysis and visualisation tool. The San Francisco Crimespotting map provides a good example of how well designed controls can enhance user ability to visualise only a subset of available information, specific for the problem under investigation.

In particular, the map uses coloured map markers to show the location of different types of crime. Users can filter the types of crime displayed by simply selecting the items from a list. A click on individual marker brings up information about a particular event. The 'date' and 'time of day' controls allows to filer the results shown on the map by any date range or for any period, or combination of periods during the day.

The 24 hour clock (literary!) takes a few moments to get used to but is a very nifty idea. I have seen various approaches so far, for example using sliders or day-time matrix, but this one takes the prize.

For other examples of visualisation of crime statistics please refer to my previous posts:

Mapping crime in Queensland
Crime maps - complex stats visualisation
Victorian version of crime stats 
UK crime statistics revisited
Mapping Crime in Canberra
MashupAustralia highlights

First spotted on Google Maps Mania

Wednesday, March 26, 2014

Fun with maps

What will you get when you combine Google Map with Google Search? Autocomplete Map! This fun application from Map Channels can deliver tonnes of laughter – just try these couple of examples for Australia:

The “Why is Australia…” map shows the Google autocomplete results for Australian states and major cities that appear in Google search when you type in 'Why is (state) so ...'. According to Google, everybody is in a state of constant surprise about how hot this country is. Unless they visit Canberra – then they only want to know why it is so cold. No surprises here!

Australia Needs…” is a similar map, only this time the map shows the autocomplete search results returned by Google when you type in '(state) needs ...'.  According to Google, Australia is in need of a major construction drive, because Melbourne needs a theme park, Adelaide needs taller buildings and Brisbane needs more bridges, Sydney needs a metro and Canberra needs more schools...

On a serious note, the collective wisdom of the crowd captured by Google can be quite a powerful information resource on issues of concern to local communities. For example, the second map demonstrates that infrastructure investment objectives of the current government may be just what the electorate needs…

First spotted on Google Maps Mania