Andreas van Hooijdonk

Found this article in SmallTimes about "anisotropic magneto-resistive
(AMR) sensors.
http://www.smalltimes.com/document_d...cument_id=8196 Nowhere
in the article GPS is mentioned. But pointing a handheld with compass in
whatever direction, does not make much sense to me, if the handheld does
not know exactly where it is situated. Any-one an idea?

--
Andreas van Hooijdonk
http://www.gps-practice-and-fun.com

Carsten Kurz

Andreas van Hooijdonk schrieb:
>
> Found this article in SmallTimes about "anisotropic magneto-resistive
> (AMR) sensors.
> http://www.smalltimes.com/document_d...cument_id=8196 Nowhere
> in the article GPS is mentioned. But pointing a handheld with compass in
> whatever direction, does not make much sense to me, if the handheld does
> not know exactly where it is situated. Any-one an idea?

Well you see how press releases work ...

They just refer to a building block or aiding component. It doesn't make
up a system or product on it's own. It's not too unusual to see this
happen. The manufacturer issues a press release or data sheet, where
possible uses for this components are given, e.g. 'personal locators,
cell-phones' etc. Then a journalist takes it up and compiles it into a
vague product option.

Using LBS/cell-detection/etc. together with directional information can
certainly be useful to a certain extent, but usually MEMS, Gyros, AMRs,
etc. are just used to aid a GPS, like the DR is implemented in the
Garmin 2650/2660.



- Carsten

--
Audio Visual Systems fon: +49 (0)2234 601886
Carsten Kurz fax: +49 (0)2234 601887
Von-Werth-Straße 111 email: audiovisual@t-online.de
50259 Pulheim / Germany WGS84:N50°57'50.2" E06°47'28.5"

Andreas van Hooijdonk

Carsten Kurz wrote:
> Andreas van Hooijdonk schrieb:
>>
>> Found this article in SmallTimes about "anisotropic magneto-resistive
>> (AMR) sensors.
>> http://www.smalltimes.com/document_d...cument_id=8196
>> Nowhere in the article GPS is mentioned. But pointing a handheld
>> with compass in whatever direction, does not make much sense to me,
>> if the handheld does not know exactly where it is situated. Any-one
>> an idea?
>
> Well you see how press releases work ...
>
> They just refer to a building block or aiding component. It doesn't
> make up a system or product on it's own. It's not too unusual to see
> this happen. The manufacturer issues a press release or data sheet,
> where possible uses for this components are given, e.g. 'personal
> locators, cell-phones' etc. Then a journalist takes it up and
> compiles it into a vague product option.
>
> Using LBS/cell-detection/etc. together with directional information
> can certainly be useful to a certain extent, but usually MEMS, Gyros,
> AMRs, etc. are just used to aid a GPS, like the DR is implemented in
> the Garmin 2650/2660.
>
>
>
> - Carsten

So, useful with GPS. Not much without. Are these sensors used in GPSRs
with electronic compass? Would be nice if it could draw the "pointing
direction" from your location on the map. You could decide in stand
still which leg of a trail to take.
--
Andreas

Carsten Kurz

Andreas van Hooijdonk schrieb:

> So, useful with GPS. Not much without. Are these sensors used in GPSRs
> with electronic compass? Would be nice if it could draw the "pointing
> direction" from your location on the map. You could decide in stand
> still which leg of a trail to take.

Some of these sensors are used as the electronic compass component in
GPSRs. There are different technologies, though. Some are in fact
electronic compasses that react to the earths magnetic field. Some are
acceleration sensors. In handheld receivers, usually electronic
compasses are used, like the fluxgate. In DR/INS systems, usually
gyros/turn rate sensors/acceleration sensors are used. They don't need
an absolute calibration, but are usually calibrated automatically by
using the GPS positions/direction. They only deliver relative turn
information. The benefit is they can't be irritated by magnetic fields
or non-level orientation.

Richard Langley has a good article on various electronic compass
technologies on GPSWorld.

http://www.gpsworld.com/gpsworld/art...l.jsp?id=68475

I have also seen such sensors being built into portable devices as
ergonomic handling elements - e.g. cameras can detect their orientation
and adjust image registration in landscape/portrait mode oder
exposure/focus control. Some devices use sensors in order to advance
screens/scrolling by quickly tilting the device. Also used in games.
Could also be used to automatically put a device into/from standy mode
(anti-ground-shot in camcorders). SteadyShot/stabilizing techniques in
camcorders also use this kind of sensor.

A 3D orientation sensor in combination with a GPS could be very useful
in certain survey applications, e.g. imagine a camera with a GPS and 3d
direction sensor. If you register position, pointing direction, focal
length, focus etc. you can pinpoint recorded objects and their size by
projeting their positions from the camera. So you don't have to be at
the objects site in order to locate it.


- Carsten




--
Audio Visual Systems fon: +49 (0)2234 601886
Carsten Kurz fax: +49 (0)2234 601887
Von-Werth-Straße 111 email: audiovisual@t-online.de
50259 Pulheim / Germany WGS84:N50°57'50.2" E06°47'28.5"

Andreas van Hooijdonk

Carsten Kurz wrote:
> Andreas van Hooijdonk schrieb:
>
>> So, useful with GPS. Not much without. Are these sensors used in
>> GPSRs with electronic compass? Would be nice if it could draw the
>> "pointing direction" from your location on the map. You could decide
>> in stand still which leg of a trail to take.
>
> Some of these sensors are used as the electronic compass component in
> GPSRs. There are different technologies, though. Some are in fact
> electronic compasses that react to the earths magnetic field. Some are
> acceleration sensors. In handheld receivers, usually electronic
> compasses are used, like the fluxgate. In DR/INS systems, usually
> gyros/turn rate sensors/acceleration sensors are used. They don't need
> an absolute calibration, but are usually calibrated automatically by
> using the GPS positions/direction. They only deliver relative turn
> information. The benefit is they can't be irritated by magnetic fields
> or non-level orientation.
>
> Richard Langley has a good article on various electronic compass
> technologies on GPSWorld.
>
> http://www.gpsworld.com/gpsworld/art...l.jsp?id=68475
>
> I have also seen such sensors being built into portable devices as
> ergonomic handling elements - e.g. cameras can detect their
> orientation and adjust image registration in landscape/portrait mode
> oder exposure/focus control. Some devices use sensors in order to
> advance screens/scrolling by quickly tilting the device. Also used in
> games. Could also be used to automatically put a device into/from
> standy mode (anti-ground-shot in camcorders). SteadyShot/stabilizing
> techniques in camcorders also use this kind of sensor.
>
> A 3D orientation sensor in combination with a GPS could be very useful
> in certain survey applications, e.g. imagine a camera with a GPS and
> 3d direction sensor. If you register position, pointing direction,
> focal length, focus etc. you can pinpoint recorded objects and their
> size by projeting their positions from the camera. So you don't have
> to be at the objects site in order to locate it.
>
>
> - Carsten

Thanks Carsten for this excellent article and your contribution
(excellent too).

--
Andreas

Barbara Smith

Thank you for using the "-" in "add-on"
It is so refreshing.

"Andreas van Hooijdonk" <ahooijdZ@piZ.beZ (NOZ)> wrote in message
news:uoadnd2dvsLcHo7cRVnyjw@scarlet.biz...
> Found this article in SmallTimes about "anisotropic magneto-resistive
> (AMR) sensors.
> http://www.smalltimes.com/document_d...cument_id=8196 Nowhere
> in the article GPS is mentioned. But pointing a handheld with compass in
> whatever direction, does not make much sense to me, if the handheld does
> not know exactly where it is situated. Any-one an idea?
>
> --
> Andreas van Hooijdonk
> http://www.gps-practice-and-fun.com
>
>
>
>

mUs1Ka

Barbara Smith wrote:
> "Andreas van Hooijdonk" <ahooijdZ@piZ.beZ (NOZ)> wrote in message
> news:uoadnd2dvsLcHo7cRVnyjw@scarlet.biz...
>> Found this article in SmallTimes about "anisotropic magneto-resistive
>> (AMR) sensors.
>> http://www.smalltimes.com/document_d...cument_id=8196
>> Nowhere in the article GPS is mentioned. But pointing a handheld
>> with compass in whatever direction, does not make much sense to me,
>> if the handheld does not know exactly where it is situated. Any-one
>> an idea?
>>
> Thank you for using the "-" in "add-on"
> It is so refreshing.
>
Do you like the one in "any-one"?

--
Ray