Azimuth Navigation
azimuthnavigation.com
Welcome to the azimuthnavigation.com website.
With the continuing commercial development of SatNav systems for
vehicles and hand held devices the user community among the general
population is rapidly increasing. There is a requirement for more
awareness of how these devices work.
Many have a strong belief in the accuracy of GPS and the maps that
are supplied to manufacturers of SatNav systems. This belief is well
founded for nowadays GPS has a high reliability. However GPS and the
maps are not without fault. As with any technical development there
are issues and problems that can occur both while in use and in
development.
When I hear people talk about GPS I feel that they do not really know
much about their satnav system. The freely used term 'GPS' is without
regard to the GPS bit only being a part of a complete integrated
system with all the different parts needing the other. It is as though
most believe, because GPS is space stuff, that understanding is beyond
them. This is not the case. GPS technology is deeply engineering, but,
the essential principles can be well understood with only a slightly
above basic knowledge. The same applies to the navigation and mapping
principles that all go together to get you, in your car, from A to B,
or Z. When it comes down to general principles this technology is not
the rocket science that it would first seem to be.
GPS systems have varying accuracy, according to make and cost and
also whether moving or stationary. Further degradation in accuracy can
occur depending on your location and present circumstance of use.
Setting up the complete nav system at the manufacturer end also has
its problems, for the end result requires a map on a flat screen. The
process of going from round earth to flat has its difficulties. Then
there is the issue of keeping maps updated as changes in road systems
occur.
These systems are a fantastic technology but they do have
limitations. Being lost or just misplaced can carry a risk factor with
severe consequences in some harsher environments. I guess we have all
heard some examples of, shall we say, the dafter misidentifications
through using car satnav.
To this end this site presents the downloadable 100 page with many
diagrams guide:
Its a clickable link but you may need to read on to see if you think
its useful for you. There is a buying info click link at the end of
this page.
The Guide provides information on how these systems work covering
aspects of GPS, how we go from round to flat and allow for our local
area, how digital maps are made and how they are used to navigate
along roads from A to Z.
It is intended for the SatNav user who wants to know more about how
GPS, navigation and mapping combine together to give us these systems.
It is a behind the scenes information and awareness for those with an
interest in understanding more about what is involved, the
difficulties encountered and some misconceptions that are around. It
is not a guide to particular systems or how to use them individually.
It will not, directly, help you to not get lost. There are other books
for not getting lost, involving map and compass. It will help you to
understand where things can go wrong, how to notice them and correct
them, or at least to know not to rely on it for the moment. It will
also give you an edge over those who think they know but really don't.
So, this technology is fantastic, but, it is designed and built by
humans. Mistakes and errors are human nature. Do not fall for others'
human nature. You can help yourself to avoid this by understanding how
systems work.
You input your destination correctly, but, the software misinterprets
or glitches and calculates an inappropriate route. The map may be not
updated. If followed blindly, unchecked, it may not be disasterous,
but is likely to lose you time, fuel, patience and, perhaps, temper.
Blind following has been done, hence those weird and strange
incidents of bridges that really are not there. Jetties that are roads
across oceans! OK, obvious (to most) extremes, but, some errors may
not be so obvious. Armed with information you are better qualified to
look out for them. You can develop a feel for when things can go wrong
and check. Stand back and take a broader look, or, resort to a paper
map. As an overview they are still valid. Some may be more up to date
than satnav maps.
Does it look right?
The technology does not anticipate for peoples' sense and appropriate
judgment. This is for you to do.
Knowing more about how the systems work can help you avoid the
patience and temper situations.
Knowing the complexities involved, even just basic knowledge, in
getting these systems into operation will aid you to understand how
errors and faults can arise and instil in you that 'Does it look
right?' mode.
I have always believed that you can say you are good at something if
you know what you don't know. 100 pages cannot cover everything of all
the included subjects. It will give you enough understanding of what
is generally going on for your SatNav use and where to dig deeper if
you wish. It is not the full story, each section could be a book in
its own right. It does cover slightly more than what many consider the
basics. It will certainly give you an advantage over others who claim
to know or to have the best system. For anyone about to embark on a
course of study I would class it useful as a first year graduate
starter information.
I say 'slightly above basics' and not 'deep rocket science', however,
complete explanation is difficult if the technical is largely avoided.
This is the nature of the game, for nature is cruel. To get a
reasonable grasp of understanding, nature requires us to think in 3D
and adds awkward irregularities on top. Nevertheless, its the sort of
subject that full deep understanding is maybe only required by those
who are paid to do it. The info here will leave you with a good grasp
and awareness of the concepts that will help you understand these
systems more and put you ahead of many.
These misconceptions about GPS and SatNav maps, well they may lead
you astray. It may be likely that some salespersons have these
misconceptions and general uncertainty about some details.
'How does it work?'
'It gives you an exact position any where in the world.'
'Exact, really, anywhere? Ok so how accurate?'
'Very accurate.'
'Give me a figure.'
'5m.'
'Based on what?'
'What? Its just accurate to 5m.'
You can beat him. If he cannot answer your accurately guided
questions, maybe you can get a discount. This guide will give you the
information.
Remember though, the salesperson may also have read it.
Another accuracy item. I often hear about pinpoint accuracy. Now what
does that mean? To me pinpoint is less than 1mm, er, like maybe the
point of a pin or needle. Yes, a very expensive and sophisticated GPS
receiver can achieve this if left standing in one place for 24 hours
plus. No doubt about it though, 5m is actually good and can reasonably
be expected, but 5m is not pinpoint.
The topics covered:
1. What GPS Is. The 3 segments.
2. How GPS Works. Positioning method, the signal, its' codes, time
and error sources.
3. Augmentation Systems. Methods to further increase accuracy.
4. What Does Accuracy Mean? Well, what does it mean, really?
5. From Round to Flat: Projections and Datums. What they are and how
and why they are used. Datums is the correct spelling.
6. Making Digital Maps. How satnav maps started. Map structures and
databases. How the system gives route navigation instructions.
Appendices. Some of us who went into this as a line of work
unfortunately realised too late just how horrible the sums are.
Formulae and further explanations of some aspects are included for
greater awareness but are separated and shoved into appendices. For
the brave.
Snips from each section are in a pdf . This also acts as a test to
ensure you have Adobe Reader on your computer. In the, nowadays,
unlikely event you do not have Adobe Reader, here is the free download
link.
The guide has been put together from my knowledge in the field as a
navigator, surveyor and mapper, offshore, coastal and onshore. It is
backed up by research in some specific areas to update myself. I have
found a lot of free content on the internet. As with many technical
topics it requires much digging to find what you think you want, and
then, is the info reliable? Again, knowing what you don't know. This,
you can also say of this guide. I may not have explained the exact
techniques used within Section 6, for example. These would be company
secrets so I couldn't tell you even if I knew the detail because I
worked for them, which I do not. The principles are there. Again, for
those interested this guide saves you the search time.
The content is reasonably technical. Whereas I have attempted easy
explanations in ways not done by any conventional methods I have so
far come across, it may in the end not be for some. For the $24.75 I
am asking for the Guide there is a 60 day refund period.
For further buying information press the compass rose below to start
navigating
John Maris 15 July 2011
This site and the products and services offered on this site are not
associated, affiliated, endorsed, or sponsored by SatNav, nor have
they been reviewed tested or certified by SatNav.
