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 Change on the horizon Sr. Associate Editor (Honorary) hrishikesh@gisdevelopment.net The natural catalyst for the development of imaging tools and technologies is the omnipresent demand for documenting land assets and also for exploring and exploiting natural resources. A prospect of what the future holds is attempted here by gleaning out precious morsels from interviews taken in the past year along with contributions from veterans. SATELLITE IMAGING The technologies involving 'imaging' have undergone a sea change. Satellite imaging is no longer a routine affair of downloading streaming data and selling it to whoever- whenever -if ever asks for it. As Marc Tremblay from Digital Globe states, "What has changed for us in the past few years is that we have tried to become a content company by focussing more on making strategic decisions regarding the areas to be captured and trying to sell them multiple times thereafter. We will be expanding our capacity to systematically image different parts of the earth significantly..." The increase in throughput of raw image data has almost doubled in the last year due to specific imaging strategies followed by the owners of the satellites. It will also reduce the redundancy in data acquisition. The availability of WorldView-1, CartoSat- 2, GeoEye-1 and the RapidEye Constellation data has changed the way imagery is perceived conventionally. The resolution of all this data has always been a part of the - 'ours is finer than yours' war. Presently, GeoEye-1 is the best. "GeoEye-1 is the Mapping Machine in Orbit" and "...it gives our customers the best resolution from any commercial satellite available in the world, plus it has the highest accuracy than any other commercial satellite available. The accuracy is 3 meters without any ground control points..." are the hard and true punches delivered by Mathew O'Conell. The future is bright, sharp and at a much finer resolution - 0.25m - is what GeoEye-2 will deliver. The much awaited launch of RadarSat-2 in December 2007 ushered in the next generation of radar data. TerraSAR along with RadarSat-2 has further whetted the appetites for moving target indication and dynamic imaging. The SSTL is designing a small satellite - the AstroSAR, a less than 500kg radar satellite with a designed life of five years and a resolution of up to 1m, capable of just these specific demands. 
About 20 years ago, the Indian IRS
satellite weighed 850 Kg. It has been
providing multi-spectral data useful for
agriculture, disaster management, etc.
"...today, we have the same capability
with 80-100 Kg satellite. At this weight,
the cost of the satellite comes down,
cost of the launch comes down, they
become more affordable, and if we
want frequent observations, we can
have a cluster of them..." said Madhavan
Nair of ISRO. The challenge is in
managing such clusters, and RapidEye
has shown the way. They have a cluster
of five small satellites in a single orbital
plane following each other 20 minutes
apart. "...Our satellites have a download
station in Norway, which allows us to
download data from each of our five
satellites during their overhead passes
permitting us to run a centralised business
model and in two to three hours,
we have some of the data processed
and available for purchase" said the
justifiably proud John Ahldrichs of
RapidEye. The SSTL, known for its small
and nano satellites, had predicted this
trend towards small -low cost - clusters
of satellites and Sir Martin Sweeting
firmly believes that, "the future will see
more satellites carrying out a range of
individual tasks but operating in networks,
with a number of small satellite
constellations. This will allow mankind
to gain a greater understanding of
space and the Earth."The huge demand from homeland security applications along with a mature market in conventional applications like crop monitoring, change detection, infrastructure planning, resource mapping etc. has kept up the demand of satellite data, " ...and with satellites like WorldView-2, there will be a ten-fold increase in our capacity. This means it would become easier to execute the content strategy as the required frequency of capturing more areas will become quite feasible," explains Marc Tremblay. AERIAL IMAGING The race between Google and Microsoft to get imagery in the hands of consumers has also raised awareness about geospatial technology. The need for higher resolution images than those traditionally acquired from satellites is fuelling the growth for airborne digital imagery, observes Dr. Jurgen Dold from Leica. The distinct shift from film (analogue) aerial photography to digital aerial photography has also changed  the photogrammetric workflow. Today, the concern over 'ccd array size' is almost passé as > 100 megapixel arrays have been designed for use in aerial cameras and the resolution obtained is almost on par with film. The automated extraction of geospatial information from aerial photographs finds a host of applications in all areas dealing with the determination of three-dimensional coordinates from as well as the interpretation of imagery but "...in spite of a large body of successful research in recent years, practical applications of fully automatic systems do not seem realistic in foreseeable future. Semi-automatic procedures, however, begin to be used successfully but contrary to fully automatic methods, semi-automatic methods need to integrate the human operator into the entire evaluating process to deal with tasks which require decisions (e.g. selection of algorithms and parameter control), quality control and where required the correction of intermediate and final results...," points out Prof Heipke. He further states that it is these semi-automatic approaches that will be 
established and strengthened in the
next few years. On the other hand,
Michael Cramer from the IFP, University
of Stuttgart, feels that since the number
of analogue aerial cameras presently
in use is far more than their digital
counterparts and also considering the
high cost in migrating from one system
of hardware to another, analogue cameras
will play a significant role for some
years to come. It will just happen that
the hard copies will be converted to digital
images to take advantage of the
faster and more efficient work flow.Today, small format aerial camera systems are getting popular due to the low cost. In the future, these small format systems will be used in projects where the demands are less stringent than precision photogrammetry. To get the best of both worlds, hyperspectral aerial imaging offers the multiband data like satellite borne sensors but due to the intrinsic advantage of being mounted on a low flying platform, the next generation aerial hyperspectral cameras are revolutionising mineral and fossil fuel exploration. To quote Larry Vance, founder of ESS Inc., "If the current satellite technology were like a magnifying glass, our PROBE-1 technology would be equivalent to an electron microscope. A satellite may be able to tell you if a particular area is a forest, but PROBE-1 can tell you what kinds of trees and plants are in that forest and the state of its health." A lot is being expected from sensors like the Probe-1, which are capable of identifying individual minerals in the soil. EXPLOITING THE DATA All the terabytes of data gathered through satellite or aerial imaging, unless you want to just admire colourful (and not so colourful) pictures, needs a trained analyst to convert it into usable information. Today, automated image classification, feature recognition and change detection are 'in demand' technologies. Software, which tackles these issues, depends almost entirely on cutting edge research and algorithms being developed. "The challenges here are primarily not technical; it's not the hardware or the software but it's the brainware!" said Prof. Fraser Taylor when asked about the challenges that lay ahead for the geospatial industry. Robert Moses of PCI seconded this and added that ...algorithms for real time image analysis are needed today and as there is too much image information available and it is going to be wasted unless we switch to an image-centric paradigm. It is a well known fact that today, we spend 80% of our time trying to find data, access data and get data into an application, while only about 20% of our time goes into real analysis. Cristopher Tucker of ERDAS is confident that a Service Oriented Architecture (SOA) will completely invert the productivity paradigm, where we will spend 5% of our time discovering data and marshaling that data into the application. The rest 95% of our time can be spent on doing actual work... Page 1 of 1
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