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Below
is a list of dates for 2006, these dates have been confirmed.
27th
September 2006
25th October 2006
22nd November 2006
20th December 2006
Last
Month….
Derek
Kerr introduced us to the world of Satellite Navigation Systems
or SATNAV in its more familiar guise. Satellite Navigation seems
to have been one of the biggest innovations to hit the motoring
world over the last few years and has become more and more sophisticated
in the process.
Derek
opened his presentation by giving us a brief lighthearted history
of navigation, from using recognizable landmarks and hilltop bonfires
through to sailors working out their location from the position
of the sun and the stars. The discovery of accurately determining
longitude made navigation a much more exact science and those
nations who were masters of this were able to establish powerful
trade routes round the world and became very rich in the process.
Modern
navigation techniques took off with the introduction of ground-based
radio systems that enabled navigators to locate shore-based transmitters
when in range. These methods were still not without drawbacks
and range and accuracy limitations could be a major problem.
Derek
then explained that GPS was developed by the U.S. Government’s
Department of Defense and given the official name of NAVSTAR (Navigation
Satellite Timing And Ranging).
GPs
consists of 3 key elements -
Satellites in space.
Monitoring stations on Earth.
Your GPS receiver.
GPS has 24 satellites that circle the Earth in 6 different orbital
paths sending out radio signals from their orbital positions 12,600
miles above us. Due to their height and large signal area footprint
on the Earth’s surface, your GPS is able to receive information
from at least 4 satellites at any one time to pinpoint your location.
There are 5 monitoring stations, 4 that are unmanned spread across
remote locations close to the equator and a master station at
Colorado Springs USA. The 4 unmanned stations receive constant
streams of data from the satellites and feed into the master station
that corrects it and sends it back up to the GPS satellites. The
users GPS receiver picks up signals from these satellites and
then works out the current location – easy really!!!! The
satellites transmit low power radio signals that travel by line
of sight. They can pass through clouds, glass or plastic but have
a bit of a problem with solid objects such as buildings. My experience
of trying to use one in the City of London proved this to be the
case.
Derek
went on to explain how data is collected from field data collectors,
aerial and satellite images and customer feedback and then used
to develop and update the digital maps. This is a time consuming
and logistically challenging process that is constantly being
improved as new technology is developed.
Derek
finished off with a small promo video from TOM-TOM to show what
modern GPS systems have to offer the general public.
Derek
went on to emphasize that a route must not be taken too literally.
Remembering some of the horrific stories in this summer’s
press, he advised that the user uses common sense and checks before
going blindly forward into some narrow track. GPS systems are
only as good as the information plugged into them. Having said
that, he had found that his personal SatNav system had been extremely
useful for him and he would not hesitate to recommend one to a
potential purchaser.
The
evening was finished off with some hands on practice with some
of the models that Derek had kindly brought along to show us.
Lots of group involvement and chatting about experiences brought
the evening to a successful conclusion.
If
you are thinking of buying a system and missed the demonstration,
I am sure Derek will be only to willing to guide you through the
minefield of technical jargon and advertising blurb. Our thanks
to Derek for a very interesting evening.
Dave
Robb
Google
Earth evolves to Beta Release 4
Some of you may have already come across Google Earth, it is a
very interesting package that allows you to view almost any location
in varying detail. It is a package that requires approx 30 Mb
of disk space and a broadband connection to get the best out of
it.. The package is currently a free download and if you have
the disk space and internet connection it is well worth a play
to see what you think about it. Some areas are available in good
detail but other like Melton are not so good.
Google has updated its Google Earth application to speed up map
rendering as well as a host of other improvements.
In Beta Release 4, Japan receives attention with a localised version,
benefiting from Japanese language support and a specific layer
of data for Japan, including 3D buildings.
KML files, Google's format for Google Earth data, now support
time-stamped images, so it is possible to view map images at different
points in time.
A new HDTV option allows users of the paid-for Pro edition to
create HDTV movies of their trips around Google Earth.
There is also support for Web mapping so that users can allow
third parties to overlay map data on any given Google Earth view.
Additionally, improvements to the layout for printing should make
driving directions easier to use.
Google has also made a featured content layer available. Once
turned on, the featured content will be overlaid onto Google Earth
maps. The content will be rotated and currently includes detailed
park descriptions from the National Park Service, articles from
National Geographic and time-stamped images showing environmental
destruction from the United Nations Environmental Program, among
others.
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