Free eBook: Testing GNSS Automotive and Telematics Applications for System Integrity
Automotive satnav systems are the single most lucrative market for GNSS receiver manufacturers, with new applications and opportunities emerging almost every day.
But with the built environment throwing up many obstacles to GNSS signal reception, how can you be sure your receiver will perform to customer expectations wherever they are in the world?
Download a free eBook to discover Spirent’s best-practice advice for testing GNSS applications for automotive and telematics. You’ll learn:
- The different types of interference that can affect in-vehicle GNSS receiver performance
- The nine basic tests that should be applied to all automotive/telematics GNSS receivers
- How to simulate real-world road conditions in a controlled, repeatable lab environment
Simply enter a few details opposite to receive your free eBook—and happy reading!
About Spirent
Spirent has been the global leader in GNSS testing for near 30 years. Spirent delivers navigation and positioning test equipment and services to governmental agencies, major manufacturers, integrators, test facilities and space agencies worldwide.
Testing GNSS systems for
automotive applications
Telematics and safety drive demands for systems integrity
The automotive landscape
Automotive sat-nav systems have become the single most lucrative
market for GNSS receiver manufacturers, with tens of millions of units
deployed worldwide and numbers continuing to grow.
The facility for drivers to receive turn-by-turn navigation instructions
in real time, and without looking away from the road has proved
increasingly popular to the extent that sales of paper maps and street
directories have begun to decline.
Page 2SPIRENT eBook
Car and commercial vehicle manufacturers are increasingly offering
navigation systems as standard or as low-cost options, and the
aftermarket sector continues to be buoyant as increasing numbers of
drivers take advantage of the technology to reduce travel time and
fuel consumption.
Now additional telematics-based applications
are further increasing the
opportunities for GNSS receivers in the
automotive sector, with systems such as vehicle
fleet tracking, fleet management and truck tracking
becoming commonplace.
Page nullSPIRENT eBook
The automotive environment
The success of GNSS receivers in automotive markets has not been
helped by the environment in which they are renullired to operate.
nullirstnull the typical automotive environment is inherently electrically
noisy, with interference sources ranging from the vehiclenulls ignition
system to any number of other onboard null systems.
Secondlynull systems are renullired to operate both when the vehicle is
stationary and when it is moving at anything up to nullnullmnull.
Page nullSPIRENT eBook
Thirdly nullnd most importantlynull todaynulls road network is a complex
mix of civil engineering that includes many structures that can
either block or renullct signals from navigation satellites.
Page nullSPIRENT eBook
Obstructions to signals
Almost every aspect of the built environment around todaynulls road
network has the potential to block some or all of the signals that a
GNSS receiver renullires to calculate its position. These range from tall
buildings and embankments that will block the signals from some of
the satellites in a constellation to overpasses and road tunnels that
will effectively cut the receiver off from all navigation signals.
The picture is further clouded by so-called on-vehicle obscuration,
which is particularly a problem for dashboard-mounted receivers that
donnull have an external antenna. nulluite simplynullthe structure of the
vehicle can and will block the signals.
Page nullSPIRENT eBook
nullatnulls morenull blocking is only half of the story. nullxternal structures
can also renullct navigation signals so that they arrive at the
receiver delayed and from the wrong direction. nullndeednullthe
combined effect of buildings forming the typical nullurban canyonnull
environment can create complenullmultipath effects that will make
a nonsense of any positional null without suitable mitigation.
Page nullSPIRENT eBook
Hybrid systems offer improvements
nullne solution to the problems caused by signal obscuration is to
combine GNSS with other navigation technologies in a hybrid systemnull
not dissimilar to those used in aerospace applications.
nullowevernullwhile the most accurate sensors such as silicon gyroscopes
and the processing resources renullired to support them are nullite
easily nullstinulld in multi-million-dollar aircraftnull only the
most cost-effective inertial sensor technologies
can be nullstinulld in automotive systems
that are expected to have bills of
materials measured in tens of dollars.
nullore information on nullybrid nullositioning can be found by downloading the Spirent
sponsored webinar here.
SPIRENT eBook
nulliving performance and reliability
nullegardless of the difnullulties inherent in both the vehicles and the
road networknull only perfect performance and reliability are acceptable
to users of automotive navigation systems. And the media are nullick
to report any deviations from this normnullsuch as a driver being
instructed to turn into a lake or even the sea.
Similarlynulla nullet manager is not likely to be overly impressed if every
vehicle in the nullet is not precisely positioned on the map. And there
would be very little point in trying to track a stolen vehicle if it were
to periodically nulldisappearnullfrom view.
Page nullSPIRENT eBook
The consenullences of poorly performing or unreliable GNSS
receivers in automotive applications can be seriousnullranging from
loss of property to loss of life.
Page nullSPIRENT eBook
nullaranteeing performance and reliability
Clearlynullthe only way to begin to guarantee the performance and
reliability of any automotive GNSS receiver is by enullaustive testing
at all stages of the product lifecycle. And such are the uninulle
problems of the automotive environment that generic GNSS
receiver testing will not be sufnullient to prove that the device is null
for its intended purpose.
So some form of road testing would appear to be necessary
to ensure that any automotive GNSS receiver will perform as
expected. nullut where on earth is the road that will provide a
representative test for a receiver that is expected to perform under
all reasonable conditionsnull
Page nullSPIRENT eBook null
The answer, of course, is that it doesnnullt enullst. And road testing
of any automotive GNSS receiver will renullire many thousands
of kilometres to be covered and consume many hundreds
of engineer-hours to gain any measure of connullence in its
performance and reliability.
Page nullSPIRENT eBook
nulll roads lead to the lab
nullortunately, there is an alternative nullone that is more practical, less
time consuming and with fewer demands on engineering resources.
nully using a suitably enullipped GNSS simulator under controlled
conditions in the test laboratorynullreceiver designers can not only verify
the fundamental performance of their receiver designsnullthey can also
apply tests that emulate all the specinull conditions under which the
receivers will be enullected to perform in automotive applications.
Cruciallynull all tests performed with a GNSS simulator are completely
controllable, repeatable and accurate down to the bit level. This
means that the simulator can be used again and againnullrepeating
exactly the same tests and allowing designers to both prove and
improve their designs.
Page nullSPIRENT eBook
What’s more, a simulator can be used to recreate signals from both
enullsting and future satellite constellations, allowing designers to
create future-proof receivers that can be used all over the world null
without leaving the lab.
Page nullSPIRENT eBook null
Typical automotive tests
nullke any other GNSS receivernullautomotive navigation systemsnull need to
be tested for the nine standard attributes ofnull
nulll can be tested using the same GNSS
simulator under software controlnull
nullore information on the G nulley receiver tests can be found by downloading
the e-book nullimulation vs nulleal nullorld Testingnull
nullld-start time to nullst null
Warm-start time to nullst null
nullt-start time to nullst null
nullnullisition sensitivity
nullracking sensitivity
nullacnullisition time
Static navigation accuracy
nullnamic navigation accuracy
nulldio frenullency interference
Page nullSPIRENT eBook null
Simulating the automotive environment
There is almost no limit to the scope of laboratory-based GNSS
simulation.
nully combining a GNSS simulator with other hardwarenullsuch as
interference generators and inertial sensor test enullipment engineers
can produce test setups that will enullercise an automotive navigation
system to its fullest enullent.
Simulation software completes the picturenulloffering the capability to
simulate roadside structuresnulloverpassesnulltunnels and the like null
all with complete repeatability.
Page nullSPIRENT eBook
The software will allow engineers to simulate both the blocking of
signals and renullctions causing multipath interference.
And motion pronulles for various vehicles can be recorded in the real
world and transferred to the simulator as NnullA data to add realism
to the simulation.
Page nullSPIRENT eBook null
nullse proven
nulln the automotive environmentnulllike any othernull proper product testing
of GNSS receivers during design, development, integration and
production is essential to prove their ability to work in their intended
application.
null simulation offers the most practical way to create tests that
reproduce all of the problems that automotive GNSS receivers might
encounter during their daily use nullwhether in navigation systems or in
telematics and tracking applications.
nullsing a suitably enullipped simulator in the laboratory systems
designers can precisely reproduce these effects either singly or in any
combination with absolute control of the simulation parameters.
Page nullSPIRENT eBook
null comparison with the nullit or missnullapproach of real-world testing,
the simulator-based approach enables enullaustive testing in less time
and without tying up engineering resources out on the road.
Page nullSPIRENT eBook null
Page 2nullSPIRENT eBook
We hope you found this Spirent Testing GNSS systems for
automotive applications E-Book of interest.
We are continually adding new content to our website
on a regular basis. Bookmark this link:
www.spirent.com/positioning
Visit the Spirent GNSS Blog, there are currently
more than 90 posts with nullto nullnew posts added
per week. nulltch up on whatnulls new:
www.spirent.com/Blog/nullositioning
nulleed more informationnull
gnss-solutionsnullpirent.com
nullharenull
nullacebook nullnkednulln nullwitter nullechnorati nulloogle Bunull nulligg nullelicious nulleddit nulltumbleupon
nullnull0nullnull
nullntact null
Spirent
nullnullnullnull nullnullnull
globalsalesnullpirent.com
www.spirent.comnullositioning
Spirent nullederal Systems
null nullnullnullnullnullnull
infonullpirentfederal.com
www.spirentfederal.com
Got a smartphonenull
Scan the null
nullde for more
information
