Investment in new London commuter rail services
has generated requirements for control and large
scale route mapping for the London Underground
Jubilee Line Extension and the CrossRail Project
which is planning to drive main line railway
tunnels under the centre of London. The Channel
Tunnel Rail Link is also expected to require
extensive route surveys once the final alignment
has been selected.
2.7 Research and development
University College London reports the following
research programmes:
* stereomatching algorithms;
* dynamic geometry of satellite imaging;
* automatic monitoring of environmental change;
* automated non-contact surface measurement;
* change detection using SAR;
* involvement in NASA Mission to Earth;
* measurement in hazardous environments; and
* calibration of CCD cameras.
The National Physical Laboratory continues to
develop precision photogrammetric cameras, bundle
solution and image analysis for high precision
metrology.
Newcastle University is researching the use of
polaroid photography for photogrammetry; and
photogrammetric measurement of ten sample city
centre sites to estimate building surface area
naturally available for fitting photovoltaic
modules.
Camera Alive demonstrated a remote real time
photogrammetric system based on electronic stills
cameras and a stereo image processing system to
the Photogrammetric Society in February 1992.
Nuclear Electric continues to develop specialised
short range cameras for use in nuclear plants.
The Oxford Orthopaedic Centre has developed a TV
image-assisted digitising system, and automatic
landmark identification for hip X-rays.
Laserscan reports the development of a stereo
matching and real time transformation system for
the Royal Aerospace Establishment, Farnborough.
2.8 Significant Changes in the period 1989-1992
Some take the view that photogrammetry has reached
a state of maturity in both development and
application. Advances in related technologies,
such as GIS, GPS, IT, reduction in computer costs,
etc, have improved its performance and range of
applications more radically than developments
within the subject which have been less
spectacular. The following trends were noted:
* Analogue plotters, although no longer made, are
still widely used and there appears to be a
brisk trade in second-hand instruments both in
UK and overseas. This may indicate that
analytical plotters have not proved
54
sufficiently more productive for routine air
survey to justify the investment where
serviceable analogue instruments are still
available.
* Analytical plotters are now used almost as
widely as analogue instruments. The associated
software has broadened the range of
applications of close range measurement and
encouraged the use of non-metric or semi-metric
cameras. A growing market for low-cost
analytical plotters is reported (forty AP190s
have been sold).
* Digital photogrammetry and stereo image
analysis systems, using digital or video
imagery or scanned photographs, are now
considered to be economically viable and
operationally robust, particularly for close
range non-contact measurement and inspection.
* Aerial survey cameras with forward motion
compensation are now widely used for large
scale mapping for engineering projects because
of the improved image quality and ability to
operate in more marginal weather conditions. In
combination with analytical plotters, it now
appears to be economic to produce 1:200 scale
plans by a combination of field and
photogrammetric survey methods.
* GPS is being used increasingly to establish
photocontrol on the ground and Airborne GPS is
being tested experimentally to supplement or
replace ground control. The predicted savings
in time and cost have yet to be demonstrated in
practice.
* User friendliness is now being taken seriously
by photogrammetric system designers to make
photogrammetry accessible to non-specialists
and occasional users.
* Economic constraints were widely reported to be
inhibiting national monitoring schemes,
education, research and investment, and have
certainly reduced the private sector market,
increased competition and reduced prices. The
Ordnance Survey has introduced shift working
for the first time to reduce production costs,
in line with private sector practice over many
decades.
2.9 The overseas contribution
The three largest photogrammetric employers
(Ordnance Survey, Directorate of Military Surveys
and BKS Surveys Ltd) retain substantial overseas
commitments in technical assistance, military
mapping and terrain modelling and contract
mapping. Many of the companies supplying systems,
contract services and consultancy also trade
worldwide.
Specialist services in underwater inspection and
non-contact measurement, developed by Camera Alive
to meet the needs of the North Sea oil industry,
have been extended to Europe, the USA, Brazil,
West Africa, South East Asia and Australia.
The Universities and Polytechnics continue to
attract a substantial proportion of overseas
students for graduate, postgraduate and specialist
courses.
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