A Remarkable Convergence
The Emergence of Digital Earth
and the Challenge to Analysis
John Richards
A Remarkable Convergence: Digital Earth
The Concept of Digital Earth
The globe is represented by a contiguous set of digital maps and
satellite images, so that spatial data, positions and relationships
are all available in digital form.
map sheets are
replaced by panning
scale is replaced by
zooming
maps are ephemeral
Because of the
digital framework
other spatial data
can be overlaid:
• social
• cultural
• citizen generated
available over the
Internet
available to all
(an open system)
A Remarkable Convergence: Digital Earth
What makes digital earth possible?
A happy convergence of four major
technologies
What challenges are there to analysing the data?
The quantitative dimension
The era of big data
Importance of the human factor
A Remarkable Convergence: Digital Earth
The convergence of four important technologies
communications
computing
Internet
navigation
earth imaging
digital earth
underpinned by concepts from cartography and GIS
… empowers the professional and lay person alike
A Remarkable Convergence: Digital Earth
The convergence of four important technologies
communications
computing
Internet
navigation
earth imaging
digital earth
• How did we get here?
• Can we reliably represent the world in virtual form?
• How important is the human factor?
A Remarkable Convergence: Digital Earth
CONVERGENCE TO ICT
COMMUNICATIONS
submarine
optical fibres
smartphones
cables satellites
mobile telephony WiFi
SERVICES
email
Ethernet
www
ARPANET Internet
COMPUTING
workstations
minicomputers
MACs
mainframes
PCs
1950
1960
1970
1980
smartphones
1990
2000
2010
2020
A Remarkable Convergence: Digital Earth
The convergence of four important technologies
✓ communications
✓ computing
Internet
navigation
earth imaging
digital earth
A Remarkable Convergence: Digital Earth
Positioning Systems
Surface based
1945-50 DECCA
1942
LORAN
1971
OMEGA
GNSS
Space based
1964 Transit
GNSS
1978-1994
1995
2012-2020
2020
GPS
GLONASS
BeiDou
Galileo
simple, accurate and immediate
A Remarkable Convergence: Digital Earth
NOW CONSIDER SATELLITE IMAGING OF THE EARTH
Landsat 1 1972
© Commonwealth of Australia (Geoscience Australia) 2004
A Remarkable Convergence: Digital Earth
1972 (1 spacecraft)
2009 (10s spacecraft)
soon (100s spacecraft)
enormous increase
in data volume
A Remarkable Convergence: Digital Earth
(courtesy of Guo Huadong, Director, Institute of Remote
Sensing and Digital Earth, Chinese Academy of Sciences)
A Remarkable Convergence: Digital Earth
DE is the product of technology convergence
communications
computing
navigation
earth imaging
digital earth
(virtual globe)
Goal: a fully developed, accurate virtual globe that acts as a surrogate
for the real world – in science, commerce, legal transactions, etc.
A Remarkable Convergence: Digital Earth
Goal: a fully developed, accurate virtual globe that acts as a surrogate
for the real world – in science, commerce, legal transactions, etc.
communications
computing
navigation
earth imaging
digital earth
(virtual globe)
manual
interpretation
decision support spectrum
we need to
examine this
machine
interpretation
A Remarkable Convergence: Digital Earth
Focus just on the analysis of satellite imagery
There are two approaches
machine learning algorithms
water
vegetation
fire burn
urban
interpretation
photointerpretation
semi-automated – classification
good visualisaton
tools are important
sophisticated algorithms are involved,
verging on artificial intelligence
A Remarkable Convergence: Digital Earth
Will traditional analytical techniques be OK in future?
Consider the data volume we are dealing with. It is determined by the frame
and pixel sizes, the number of channels and the dynamic range of the sensor.
channels
pixel size
pix
black
dynamic
range
white
frame size
Sensor
Year
Data Volume MB
Landsat MSS
1972
20
Landsat ETM+
1999
240
World View 3
2014
1,400
Sensor
Year
Landsat MSS
1972
250
Landsat ETM+
1999
3,200
World View 3
2014
268,000
MB per 2,500km
approximately one
strip over Australia
A Remarkable Convergence: Digital Earth
This highlights the typical volumes of data that have to be
assimilated and processed in the digital earth framework
Complicated by layers of
• cultural data
• social data
• spatial data
• image interpretations
digital (virtual) globe
How do we cope with the large
and complex data volumes to
derive maximum benefit from
the availability of digital earth?
A Remarkable Convergence: Digital Earth
Analysis of big data in digital earth
Three potential approaches
A Remarkable Convergence: Digital Earth
Use more powerful computing technology
Takes digital earth out of the reach of a
citizen with desk top capabilities.
But can generate derived products that are
accessible from desk top machines.
Background image from http://www.unixmen.com/linux-as-an-os-for-supercomputers-for-scientific-research/
A Remarkable Convergence: Digital Earth
Use more efficient analytical algorithms
Need to constrain processing time to better
than linear dependence on data volume, if
possible.
Still some way to go to get generalised
procedures that work with mixed data types
(optical, radar, lidar for example).
Background image from http://www.cs.amherst.edu/ccm/cs31/
A Remarkable Convergence: Digital Earth
Emulate Human Reasoning
(artificial intelligence)
Humans are good at complex reasoning
over mixed data types.
Consider a simple example …
Background image from http://leadtrigger.co.uk/sales-library/artificial-intelligence-in-a-crm/
A Remarkable Convergence: Digital Earth
Human visual information processing
0.0128deg
~500Mpixel
over 90deg x 90deg
field of view
~1 million colours, gives about 3B per pixel for each colour primary.
Maximum frame rate of about 20 per second; not all pixels are
viewed on each frame, but just a subset in the region of the field
of view currently being looked at.
If all pixels in a scene were assimilated then the processing rate
would be about 30GB per second.
Use a lower rate of 0.3GB per second. Then every hour about 1TB is
processed, giving 10TB in a 10 hour day per person.
A Remarkable Convergence: Digital Earth
Take a citizen science example
observes an event,
such as a fire
May take about a second to assimilate and cross check ~ 0.3GB.
Message passed to authorities, say 200 words (1200 characters at
8B per character) ~ 10kB.
This represents a compression of about 30,000!
This is the result of the human reasoning system’s ability to undertake
complex analysis and to reduce large data volumes to important facts.
A Remarkable Convergence: Digital Earth
Human Reasoning
Machine Processing
Can make complex, high level
decisions; spatial reasoning is
easy.
High level reasoning ability is
poor by comparison at this time;
spatial reasoning is challenging.
While data rates might be high,
decision making is slow.
Very high processing speeds.
Is prone to inconsistency and
errors, especially when tired.
Error free processing, in
principle, with no fatigue.
Best of both worlds would be achieved if we can emulate
human reasoning by machine (artificial intelligence).
A Remarkable Convergence: Digital Earth
Human Reasoning and Emulation
We can have artificial intelligence in the sense
of expert system software on machines, or
we could actually benefit by group decision
making by citizens over the Internet.
Background images from http://www.igcseict.info/theory/7_2/expert/
and http://www.theguardian.com/technology/2009/sep/30/anti-virus-software-ants
A Remarkable Convergence: Digital Earth
AI
analysis
citizen 1
Internet
citizen 2
citizen 3
group intelligence
web knowledge infrastructure
with a virtual globe basis
an agent, skilled in turning
client requirements into a
set of specifications for
data analysts, and skilled
in combining knowledge
knowledge
broker
client
Facilitates links and networks:
Citizen to citizen
Citizen to expert
Citizen to data
Citizen to knowledge
Expert to data
Expert to knowledge
A Remarkable Convergence: Digital Earth
Concluding Remarks
The Internet and Digital Earth grow and benefit from human
ingenuity.
Domain-specific globes can now be used in trade, tourism and
agricultural applications (the Queensland Globe), for legal
property and architectural purposes (VANZI, digital cities) and
in security applications.
With increasing data volumes and rates we will depend on
smart methods for analysis when using the digital earth in
decision support situations, most likely those techniques that
emulate human reasoning or group intelligence.
A Remarkable Convergence: Digital Earth
A Remarkable Convergence: Digital Earth
Why is the Internet so successful?
“My first suspicion of something born so instantaneously perfect
is an alien origin. There was probably a meeting on a distant
planet where they debated whether or not it was time for the
earth to have the web.
‘They’ll only botch it up’, the opponents probably argued.
‘They’ll put all kinds of garbage on it and ruin our good idea.’”
R.W. Lucky, Bellcore, 1995
A Remarkable Convergence: Digital Earth
“But the alien proponents and supporters of the Web carried
the day. ‘The earth has all sorts of talented people eager to
get their material out to the public’ they undoubtedly said.
‘Wonderful things will happen, just wait and see.’”
“The Web is proving the efficacy of the long believed and hoped
for Field of Dreams approach: if we build it they will come.
The people of the earth have been empowered by the Web and
there has been an incredible outpouring of creativity …
When you empower a few, its not much competition. But when
you empower tens of millions, surprising things will happen,
some of them breathtakingly good”
A Remarkable Convergence: Digital Earth
price USD/MB
Apart from processor speed a major factor has been
the falling cost of memory
1000
“the biggest technology impact
on society will be the falling cost
of computer memory”
L. Free, Sydney, late 1970s
100
10
1
price cents/MB
10
1
0.1
0.01
0.001
1980 1985 1990 1995 2000 2005 2010 2015
2000
128MB
$100
2014
8GB
$10
$10/TB
Based on: hblok.net/blog/posts/2013/02/13/historical-cost-of-computer-memory-and-storage/
A Remarkable Convergence: Digital Earth
1967 US NRC Summer Study on Useful
Applications of Earth-Oriented Satellites
Telecommunications
Agriculture
Forestry
Geography
Geology
Hydrology
Meteorology
Oceanography
Geodesy & Cartography
Sensors & Data Systems
Navigation
A Remarkable Convergence: Digital Earth
(courtesy of Guo Huadong, Director, Institute of Remote
Sensing and Digital Earth, Chinese Academy of Sciences)
A Remarkable Convergence: Digital Earth
See www.mocom2020.com/2009/05/evolution-of-computer-capacity-and-costs/
A Remarkable Convergence: Digital Earth
http://www.computerhistory.org/atchm/wp-content/uploads/2015/03/Screen-Shot-2015-03-22-at-6.56.53-AM.png
A Remarkable Convergence: Digital Earth
35 years ago
25 years ago
today
© Apollo Mapping
optical images
colour IR air photo
buried ancient channel
of the Nile river
radar image
A Remarkable Convergence: Digital Earth
Source: IDC's Digital Universe Study Executive Summary, December 2012