[Talk-cz] presnejsi trackovani pro OSM
Vlákno 13.10. - 15.10.2012, počet zpráv: 17
Ahoj vespolek,
trochu jsem hledal, jeslti by se nejakymi rozumne dostupnymi prostredky
nedala zlepsit presnost tracklogu, zejmena ziskanych na kole, ale klidne
i pesky a autem. Zlobi mne to hlavne pri rychlejsi jizde na kole spojene
s rycheljsimi zmenami smeru (kdy Garmin 60CSx "nestiha zatacet") a v lese, kde
je presnost vubec na pytel (60CSx ani Holux M-1000C). Zacal jsem uvazovat
o nejakem modulu, ktery by sbiral raw GPS data na dostatecne frekvenci, na
nichz by se dal udelat postprocesing - ale ne v cenove kategorii 30.000CZK
a vic (tedy profi GPS zarizeni). Narazil jsem dve firmicky, ktere neco
takoveho delaji (a do jiste miry spolu i spolupracuji): Optimalsystem.de
a OneTalent-GNSS. Navrhy desek dela Michele Bavaro pro obe firmy a primarne
pracuje pro ten OneTalent-GNSS - nize najdete jak moje dotazy na neho, tak
i jeho odpovedi. Prestoze vyjadruje skepsi kolem dosazeni presnosti 1m
v lese (pricem 1m povazuji pro potreby OSM naprosto dostacujici), nicmene
porad by to mohlo by podstatne zlepseni proti tomu, co mam ted. Uvazuji
o jednom z nasledujicich modulu:
http://www.onetalent-gnss.com/ideas/wireless/denga10logbt
http://www.onetalent-gnss.com/ideas/wireless/rappen10logbt
Jinak data pro postprocesing by napr. pro okoli Brna mely byt zdarma
dostupne ze site stanic EUREF:
http://www.epncb.oma.be/_networkdata/stationlist.php
pro Brno napr. tady:
http://www.epncb.oma.be/_networkdata/siteinfo4onestation.php?station=TUBO_11503M001
Moje dotazy do fora:
- Hrali jste si nekdo s necim podobnym?
- Meli byste chut a cas se nekdo do toho taky pustit?
Diky,
Petr
From: Michele Bavaro [mailto:mbavaro na onetalent-gnss.com]
Sent: Sunday, October 07, 2012 10:19 PM
To: Petr Holub
Subject: Re: a module for accurate mapping for OSM
Hello Petr,
Thanks for getting in touch!
It will be very difficult to guarantee 1m accuracy (standalone real-time or differential post-processed) under dense
foliage.
Trees are well known to disrupt carrier phase information which is essential to achieve such accuracies.
There is something about it on the German forum Kowoma:
http://www.kowoma.de/gpsforum/viewtopic.php?f=1&t=3248&p=14992#p14992
Denga10 and Rappen10 are not suitable. But their _LogBt or _LogWi version instead might work: they have a battery which
will last a longer than 6hr, logging, and Bluetooth - or pretty much any other wireless communication system. Of course
both have raw measurements but their carrier phase will be impaired under foliage as I wrote above.
I am finalising the firmware in these days (today I had logging with fatfs and USB MSC running simultaneously finally)
but -as it is quite experimental- I cannot really claim that is a "set and forget" kind of solution.
Firmware is open though and if you have programming skills you may modify it to your needs.
I am also working on enclosures... I have the bare boxes but I need to hand-tool them.
If you are happy to do it by yourself I can make a discount:
http://www.onetalent-gnss.com/announcements/contributorsgetafreereceiver
Unfortunately in any case I cannot make you a lower price than 250EUR+VAT+shipping as I hand assemble the boards and I
don't sell many of them so I cannot reduce the price by producing volumes.
I would love to help you but I understand that compared to a 100EUR logger it's a lot of money to invest.
By the way, all new Mediatek receivers have 10Hz and very high sensitivity... the new MTK3333 also has Glonass.
ST Microelectronics has the STA8088FG which performs very well and it's very low cost.
Not to mention of course the usual CSR GSD4E and Skytraq Venus..
Have you looked at Fastrax, Locosys, and GlobalTop?
I am very happy to help an enthusiastic mapper, please let me know if I can do something else for you.
Best regards,
Michele
On 7 October 2012 18:52, Petr Holub <hopet na ics.muni.cz> wrote:
Hello,
I'm looking for a GNSS module that could improve precision of my
mapping efforts for Openstreetmap - mainly mountainbike trails and
hiking paths in the Czech Republic (http://www.mtbmap.cz/). Up to
now, I'm using Sirf3-based Garmin 60CSx mounted on the MTB handlebar,
and MTK3329-based Holux M-1000C logger switched to 10Hz, mounted to
my MTB helmet. While Garmin 60CSx produces reasonably precise
results while hiking open-air, it has significantly worse behavior
in hilly forests and 1Hz operation is not sufficient for accurately
tracking shape of paths when riding fast on my bike. Holux provides
improves tracking of fast motion, but it has usually significantly
worse accuracy (i.e., wanders more) despite being mounted on top
of my helmet and thus having good sky view.
Thus I'm looking for a reasonably priced (<400 EUR, ideally 200-300EUR)
solution for more accurate logging of MTB trails, ideally at 4Hz or better
and approx. 1m accuracy - obviously I don't need 1cm accuracy, but I'd
like to have 1m accuracy even under forest foliage. I don't need precise
real-time output (Garmin will work fine for real-time navigation;
having, e.g., additional Bluetooth NMEA output to verify operation,
would be nice for the module, but it is not conditio sine qua non).
I assume to put the device on my helmet again, replacing the Holux
logger - so I shouldn't be excessively large or heavy. An alternative
solution would be to have the device in my backpack and only put the
antenna onto the helmet. The device should keep working on a battery
for at least 6hrs. The ideal workflow for me is to keep the device
logging into its internal memory, come back home, download the raw
log and post-process it using RTKLIB to achieve 1m log accuracy, without
need for paying recurring costs (such as CZEPOS professional DGPS correction).
I'm doing this effort as a hobbyist, thus minimizing operational costs
is important.
Is there some solution for this in your portfolio? I was looking into
Denga10LogBt, but I'm not sure if it meets my requirements - to sum it
up:
- battery operated for at least 6 hours
- internal RAW logging for later processing
- 1m accuracy under foliage (50cm accuracy would be absolutely perfect)
- 4Hz or higher frequency (about 10Hz is ideal)
- either whole device or at least the antenna should be helmet-mountable
- helmet-mountable part of the device (or complete device) needs to
be weather-sealed and needs to have reasonable weight (I can try to
build my own housing, but not sure...)
- post-processing should avoid need for paid data (such as CZEPOS)
- ideally use open-source software to process the data
Maybe my wishes still can't be fulfilled, but I've just stumbled over
your website and the devices really look promising...
Thanks,
Petr
--
Michele Bavaro
Consultant at OneTalent GNSS
Mob. IT: +39 347 009 4377
Skype: onetalent-gnss
http://www.onetalent-gnss.com
Ahoj,
nejsem si jist, zda si chces hrat s nekonvencnim merenim 2) nebo
opravdu potrebujes jen lepsi klasicky pristroj 1).
Nicmene problem lesa je predevsim vicecestne sireni signalu, utlum,
terenni prekazky a voda po desti.
2) kodove mereni
* frekvence vzorkovani signalu u kapesnich prijimacu neni problem 1hz,
nikdy jsem se zatacenim nemel problem. Samozrejme v terenu vzdy
existuje jista mira nejistoty/nepresnosti.
* Garmin Vista co jsem mel byl pro mapovaci trackovani temer nepouzitelny
1) nekonformni mereni, tj.
* fazova mereni
* fazova mereni na vice GNSS
* fazove mereni na vice frekvencich jednoho GNSS
* fazove/kodove mereni s postprocessnim zpresnenim
http://cs.wikipedia.org/wiki/GNSS
* to o cem se pise nize v mailu je mereni fazove uplne odlisne od
kodoveho, ma to sve vlastni problemy. Je hodne metod jak s tim
pracovat...
* abys mohl delat postprocessing potrebujes RINEX nebo podobny
vystupni format a na korekce kdysi byl nejaky free sw, lze delat nad
fazovym i kodovym merenim
* samotne fazove mereni je nejednoznacne a ma problemy s prerusenim signalu
Prakticky se mi to v roce 2007 nepodarilo dat dokupy sestavu s kodovym
mereni+postproc.
PS: jinak lesaci se touto problematikou docela casto bavi, napr:
http://www.lesycr.cz/odborne-rady/granty-a-dotace/Documents/optimalizace_tds_pomoci_gps-web.pdf
ha
hanoj
2012/10/13 Petr Holub <hopet na ics.muni.cz>:
zobrazit citaci
> Ahoj vespolek,
>
> trochu jsem hledal, jeslti by se nejakymi rozumne dostupnymi prostredky
> nedala zlepsit presnost tracklogu, zejmena ziskanych na kole, ale klidne
> i pesky a autem. Zlobi mne to hlavne pri rychlejsi jizde na kole spojene
> s rycheljsimi zmenami smeru (kdy Garmin 60CSx "nestiha zatacet") a v lese, kde
> je presnost vubec na pytel (60CSx ani Holux M-1000C). Zacal jsem uvazovat
> o nejakem modulu, ktery by sbiral raw GPS data na dostatecne frekvenci, na
> nichz by se dal udelat postprocesing - ale ne v cenove kategorii 30.000CZK
> a vic (tedy profi GPS zarizeni). Narazil jsem dve firmicky, ktere neco
> takoveho delaji (a do jiste miry spolu i spolupracuji): Optimalsystem.de
> a OneTalent-GNSS. Navrhy desek dela Michele Bavaro pro obe firmy a primarne
> pracuje pro ten OneTalent-GNSS - nize najdete jak moje dotazy na neho, tak
> i jeho odpovedi. Prestoze vyjadruje skepsi kolem dosazeni presnosti 1m
> v lese (pricem 1m povazuji pro potreby OSM naprosto dostacujici), nicmene
> porad by to mohlo by podstatne zlepseni proti tomu, co mam ted. Uvazuji
> o jednom z nasledujicich modulu:
> http://www.onetalent-gnss.com/ideas/wireless/denga10logbt
> http://www.onetalent-gnss.com/ideas/wireless/rappen10logbt
> Jinak data pro postprocesing by napr. pro okoli Brna mely byt zdarma
> dostupne ze site stanic EUREF:
> http://www.epncb.oma.be/_networkdata/stationlist.php
> pro Brno napr. tady:
> http://www.epncb.oma.be/_networkdata/siteinfo4onestation.php?station=TUBO_11503M001
>
>
> Moje dotazy do fora:
> - Hrali jste si nekdo s necim podobnym?
> - Meli byste chut a cas se nekdo do toho taky pustit?
>
> Diky,
> Petr
>
>
>
> From: Michele Bavaro [mailto:mbavaro na onetalent-gnss.com]
> Sent: Sunday, October 07, 2012 10:19 PM
> To: Petr Holub
> Subject: Re: a module for accurate mapping for OSM
>
> Hello Petr,
>
> Thanks for getting in touch!
>
> It will be very difficult to guarantee 1m accuracy (standalone real-time or differential post-processed) under dense
> foliage.
> Trees are well known to disrupt carrier phase information which is essential to achieve such accuracies.
> There is something about it on the German forum Kowoma:
> http://www.kowoma.de/gpsforum/viewtopic.php?f=1&t=3248&p=14992#p14992
>
> Denga10 and Rappen10 are not suitable. But their _LogBt or _LogWi version instead might work: they have a battery which
> will last a longer than 6hr, logging, and Bluetooth - or pretty much any other wireless communication system. Of course
> both have raw measurements but their carrier phase will be impaired under foliage as I wrote above.
> I am finalising the firmware in these days (today I had logging with fatfs and USB MSC running simultaneously finally)
> but -as it is quite experimental- I cannot really claim that is a "set and forget" kind of solution.
> Firmware is open though and if you have programming skills you may modify it to your needs.
> I am also working on enclosures... I have the bare boxes but I need to hand-tool them.
> If you are happy to do it by yourself I can make a discount:
> http://www.onetalent-gnss.com/announcements/contributorsgetafreereceiver
>
> Unfortunately in any case I cannot make you a lower price than 250EUR+VAT+shipping as I hand assemble the boards and I
> don't sell many of them so I cannot reduce the price by producing volumes.
>
> I would love to help you but I understand that compared to a 100EUR logger it's a lot of money to invest.
> By the way, all new Mediatek receivers have 10Hz and very high sensitivity... the new MTK3333 also has Glonass.
> ST Microelectronics has the STA8088FG which performs very well and it's very low cost.
> Not to mention of course the usual CSR GSD4E and Skytraq Venus..
> Have you looked at Fastrax, Locosys, and GlobalTop?
>
> I am very happy to help an enthusiastic mapper, please let me know if I can do something else for you.
>
> Best regards,
> Michele
>
>
>
>
>
> On 7 October 2012 18:52, Petr Holub <hopet na ics.muni.cz> wrote:
> Hello,
>
> I'm looking for a GNSS module that could improve precision of my
> mapping efforts for Openstreetmap - mainly mountainbike trails and
> hiking paths in the Czech Republic (http://www.mtbmap.cz/). Up to
> now, I'm using Sirf3-based Garmin 60CSx mounted on the MTB handlebar,
> and MTK3329-based Holux M-1000C logger switched to 10Hz, mounted to
> my MTB helmet. While Garmin 60CSx produces reasonably precise
> results while hiking open-air, it has significantly worse behavior
> in hilly forests and 1Hz operation is not sufficient for accurately
> tracking shape of paths when riding fast on my bike. Holux provides
> improves tracking of fast motion, but it has usually significantly
> worse accuracy (i.e., wanders more) despite being mounted on top
> of my helmet and thus having good sky view.
>
> Thus I'm looking for a reasonably priced (<400 EUR, ideally 200-300EUR)
> solution for more accurate logging of MTB trails, ideally at 4Hz or better
> and approx. 1m accuracy - obviously I don't need 1cm accuracy, but I'd
> like to have 1m accuracy even under forest foliage. I don't need precise
> real-time output (Garmin will work fine for real-time navigation;
> having, e.g., additional Bluetooth NMEA output to verify operation,
> would be nice for the module, but it is not conditio sine qua non).
> I assume to put the device on my helmet again, replacing the Holux
> logger - so I shouldn't be excessively large or heavy. An alternative
> solution would be to have the device in my backpack and only put the
> antenna onto the helmet. The device should keep working on a battery
> for at least 6hrs. The ideal workflow for me is to keep the device
> logging into its internal memory, come back home, download the raw
> log and post-process it using RTKLIB to achieve 1m log accuracy, without
> need for paying recurring costs (such as CZEPOS professional DGPS correction).
> I'm doing this effort as a hobbyist, thus minimizing operational costs
> is important.
>
> Is there some solution for this in your portfolio? I was looking into
> Denga10LogBt, but I'm not sure if it meets my requirements - to sum it
> up:
> - battery operated for at least 6 hours
> - internal RAW logging for later processing
> - 1m accuracy under foliage (50cm accuracy would be absolutely perfect)
> - 4Hz or higher frequency (about 10Hz is ideal)
> - either whole device or at least the antenna should be helmet-mountable
> - helmet-mountable part of the device (or complete device) needs to
> be weather-sealed and needs to have reasonable weight (I can try to
> build my own housing, but not sure...)
> - post-processing should avoid need for paid data (such as CZEPOS)
> - ideally use open-source software to process the data
>
> Maybe my wishes still can't be fulfilled, but I've just stumbled over
> your website and the devices really look promising...
>
> Thanks,
> Petr
>
>
>
>
> --
> Michele Bavaro
> Consultant at OneTalent GNSS
> Mob. IT: +39 347 009 4377
> Skype: onetalent-gnss
> http://www.onetalent-gnss.com
>
>
>
>
> _______________________________________________
> Talk-cz mailing list
> Talk-cz na openstreetmap.org
> http://lists.openstreetmap.org/listinfo/talk-cz
Já jsem v autě dosáhl slušných výsledků s Qstarz BT-Q1000X na 5 Hz v kombinaci s funkcí Kalman Filter v http://www.efficasoft.com/gpsutilities/windowsmobile_professional.html. Největší gró tam asi dělá ten Kalman filtr. Možná že by šlo použít pro postprocessing toto:
https://github.com/lacker/ikalman
Nicméně pro ostré zatáčky v lese by pomohl jedině GPS v kombinaci s gyroskopem/akcelerometrem.
MK
----- Original Message -----
From: Petr Holub
[mailto:hopet na ics.muni.cz]
To: 'OpenStreetMap Czech Republic'
[mailto:talk-cz na openstreetmap.org]
Sent: Sat, 13 Oct 2012 19:58:05
+0200
Subject: [Talk-cz] presnejsi trackovani pro OSM
zobrazit citaci
> Ahoj vespolek,
>
> trochu jsem hledal, jeslti by se nejakymi rozumne dostupnymi prostredky
> nedala zlepsit presnost tracklogu, zejmena ziskanych na kole, ale klidne
> i pesky a autem. Zlobi mne to hlavne pri rychlejsi jizde na kole spojene
> s rycheljsimi zmenami smeru (kdy Garmin 60CSx "nestiha zatacet") a v lese,
> kde
> je presnost vubec na pytel (60CSx ani Holux M-1000C). Zacal jsem uvazovat
> o nejakem modulu, ktery by sbiral raw GPS data na dostatecne frekvenci, na
> nichz by se dal udelat postprocesing - ale ne v cenove kategorii 30.000CZK
> a vic (tedy profi GPS zarizeni). Narazil jsem dve firmicky, ktere neco
> takoveho delaji (a do jiste miry spolu i spolupracuji): Optimalsystem.de
> a OneTalent-GNSS. Navrhy desek dela Michele Bavaro pro obe firmy a primarne
> pracuje pro ten OneTalent-GNSS - nize najdete jak moje dotazy na neho, tak
> i jeho odpovedi. Prestoze vyjadruje skepsi kolem dosazeni presnosti 1m
> v lese (pricem 1m povazuji pro potreby OSM naprosto dostacujici), nicmene
> porad by to mohlo by podstatne zlepseni proti tomu, co mam ted. Uvazuji
> o jednom z nasledujicich modulu:
> http://www.onetalent-gnss.com/ideas/wireless/denga10logbt
> http://www.onetalent-gnss.com/ideas/wireless/rappen10logbt
> Jinak data pro postprocesing by napr. pro okoli Brna mely byt zdarma
> dostupne ze site stanic EUREF:
> http://www.epncb.oma.be/_networkdata/stationlist.php
> pro Brno napr. tady:
> http://www.epncb.oma.be/_networkdata/siteinfo4onestation.php?station=TUBO_11503M001
>
>
> Moje dotazy do fora:
> - Hrali jste si nekdo s necim podobnym?
> - Meli byste chut a cas se nekdo do toho taky pustit?
>
> Diky,
> Petr
>
>
>
> From: Michele Bavaro [mailto:mbavaro na onetalent-gnss.com]
> Sent: Sunday, October 07, 2012 10:19 PM
> To: Petr Holub
> Subject: Re: a module for accurate mapping for OSM
>
> Hello Petr,
>
> Thanks for getting in touch!
>
> It will be very difficult to guarantee 1m accuracy (standalone real-time or
> differential post-processed) under dense
> foliage.
> Trees are well known to disrupt carrier phase information which is essential
> to achieve such accuracies.
> There is something about it on the German forum Kowoma:
> http://www.kowoma.de/gpsforum/viewtopic.php?f=1&t=3248&p=14992#p14992
>
> Denga10 and Rappen10 are not suitable. But their _LogBt or _LogWi version
> instead might work: they have a battery which
> will last a longer than 6hr, logging, and Bluetooth - or pretty much any
> other wireless communication system. Of course
> both have raw measurements but their carrier phase will be impaired under
> foliage as I wrote above.
> I am finalising the firmware in these days (today I had logging with fatfs
> and USB MSC running simultaneously finally)
> but -as it is quite experimental- I cannot really claim that is a "set and
> forget" kind of solution.
> Firmware is open though and if you have programming skills you may modify it
> to your needs.
> I am also working on enclosures... I have the bare boxes but I need to
> hand-tool them.
> If you are happy to do it by yourself I can make a discount:
> http://www.onetalent-gnss.com/announcements/contributorsgetafreereceiver
>
> Unfortunately in any case I cannot make you a lower price than
> 250EUR+VAT+shipping as I hand assemble the boards and I
> don't sell many of them so I cannot reduce the price by producing volumes.
>
> I would love to help you but I understand that compared to a 100EUR logger
> it's a lot of money to invest.
> By the way, all new Mediatek receivers have 10Hz and very high
> sensitivity... the new MTK3333 also has Glonass.
> ST Microelectronics has the STA8088FG which performs very well and it's very
> low cost.
> Not to mention of course the usual CSR GSD4E and Skytraq Venus..
> Have you looked at Fastrax, Locosys, and GlobalTop?
>
> I am very happy to help an enthusiastic mapper, please let me know if I can
> do something else for you.
>
> Best regards,
> Michele
>
>
>
>
>
> On 7 October 2012 18:52, Petr Holub <hopet na ics.muni.cz> wrote:
> Hello,
>
> I'm looking for a GNSS module that could improve precision of my
> mapping efforts for Openstreetmap - mainly mountainbike trails and
> hiking paths in the Czech Republic (http://www.mtbmap.cz/). Up to
> now, I'm using Sirf3-based Garmin 60CSx mounted on the MTB handlebar,
> and MTK3329-based Holux M-1000C logger switched to 10Hz, mounted to
> my MTB helmet. While Garmin 60CSx produces reasonably precise
> results while hiking open-air, it has significantly worse behavior
> in hilly forests and 1Hz operation is not sufficient for accurately
> tracking shape of paths when riding fast on my bike. Holux provides
> improves tracking of fast motion, but it has usually significantly
> worse accuracy (i.e., wanders more) despite being mounted on top
> of my helmet and thus having good sky view.
>
> Thus I'm looking for a reasonably priced (<400 EUR, ideally 200-300EUR)
> solution for more accurate logging of MTB trails, ideally at 4Hz or better
> and approx. 1m accuracy - obviously I don't need 1cm accuracy, but I'd
> like to have 1m accuracy even under forest foliage. I don't need precise
> real-time output (Garmin will work fine for real-time navigation;
> having, e.g., additional Bluetooth NMEA output to verify operation,
> would be nice for the module, but it is not conditio sine qua non).
> I assume to put the device on my helmet again, replacing the Holux
> logger - so I shouldn't be excessively large or heavy. An alternative
> solution would be to have the device in my backpack and only put the
> antenna onto the helmet. The device should keep working on a battery
> for at least 6hrs. The ideal workflow for me is to keep the device
> logging into its internal memory, come back home, download the raw
> log and post-process it using RTKLIB to achieve 1m log accuracy, without
> need for paying recurring costs (such as CZEPOS professional DGPS
> correction).
> I'm doing this effort as a hobbyist, thus minimizing operational costs
> is important.
>
> Is there some solution for this in your portfolio? I was looking into
> Denga10LogBt, but I'm not sure if it meets my requirements - to sum it
> up:
> - battery operated for at least 6 hours
> - internal RAW logging for later processing
> - 1m accuracy under foliage (50cm accuracy would be absolutely perfect)
> - 4Hz or higher frequency (about 10Hz is ideal)
> - either whole device or at least the antenna should be helmet-mountable
> - helmet-mountable part of the device (or complete device) needs to
> be weather-sealed and needs to have reasonable weight (I can try to
> build my own housing, but not sure...)
> - post-processing should avoid need for paid data (such as CZEPOS)
> - ideally use open-source software to process the data
>
> Maybe my wishes still can't be fulfilled, but I've just stumbled over
> your website and the devices really look promising...
>
> Thanks,
> Petr
>
>
>
>
> --
> Michele Bavaro
> Consultant at OneTalent GNSS
> Mob. IT: +39 347 009 4377
> Skype: onetalent-gnss
> http://www.onetalent-gnss.com
>
>
>
>
> _______________________________________________
> Talk-cz mailing list
> Talk-cz na openstreetmap.org
> http://lists.openstreetmap.org/listinfo/talk-cz
>
zobrazit citaci
> Nicméně pro ostré zatáčky v lese by pomohl jedině GPS v kombinaci s
> gyroskopem/akcelerometrem.
*** to mne taky uz napadlo proc se to v praxi nepouziva, vzdyt 3D
akcelerometr a elekro-kompas ma uz kazdy Android....
hanoj
Prý to je hodně špatné:
http://stackoverflow.com/questions/7829097/android-accelerometer-accuracy-inertial-navigation
Třeba by se dalo něco sestavit na platformě Arduino, ale to by musel nějaký znalec...
http://arduino.cc/forum/index.php?topic=58048.0
http://arduino.cc/forum/index.php/topic,104951.0.html
MK
----- Original Message -----
From: hanoj [mailto:ehanoj na gmail.com]
To:
OpenStreetMap Czech Republic [mailto:talk-cz na openstreetmap.org]
Sent: Sat,
13 Oct 2012 21:24:37 +0200
Subject: Re: [Talk-cz] presnejsi trackovani pro
OSM
zobrazit citaci
> > Nicméně pro ostré zatáčky v lese by pomohl jedině GPS v kombinaci
> s
> gyroskopem/akcelerometrem.
*** to mne taky uz napadlo proc se to v praxi
zobrazit citaci
> nepouziva, vzdyt 3D
akcelerometr a elekro-kompas ma uz kazdy
zobrazit citaci
> Android....
hanoj
_______________________________________________
Talk-cz
zobrazit citaci
> mailing
> list
Talk-cz na openstreetmap.org
http://lists.openstreetmap.org/listinfo/talk-cz
Zdar,
co třeba tohle: http://gpspp.sakura.ne.jp/rtklib/rtklib_beagleboard.htm
(viz první odkaz na pdf)
Zdeněk
Dne 13.10.2012 19:58, Petr Holub napsal(a):
zobrazit citaci
> Ahoj vespolek,
>
> trochu jsem hledal, jeslti by se nejakymi rozumne dostupnymi prostredky
> nedala zlepsit presnost tracklogu, zejmena ziskanych na kole, ale klidne
> i pesky a autem. Zlobi mne to hlavne pri rychlejsi jizde na kole spojene
> s rycheljsimi zmenami smeru (kdy Garmin 60CSx "nestiha zatacet") a v lese, kde
> je presnost vubec na pytel (60CSx ani Holux M-1000C). Zacal jsem uvazovat
> o nejakem modulu, ktery by sbiral raw GPS data na dostatecne frekvenci, na
> nichz by se dal udelat postprocesing - ale ne v cenove kategorii 30.000CZK
> a vic (tedy profi GPS zarizeni). Narazil jsem dve firmicky, ktere neco
> takoveho delaji (a do jiste miry spolu i spolupracuji): Optimalsystem.de
> a OneTalent-GNSS. Navrhy desek dela Michele Bavaro pro obe firmy a primarne
> pracuje pro ten OneTalent-GNSS - nize najdete jak moje dotazy na neho, tak
> i jeho odpovedi. Prestoze vyjadruje skepsi kolem dosazeni presnosti 1m
> v lese (pricem 1m povazuji pro potreby OSM naprosto dostacujici), nicmene
> porad by to mohlo by podstatne zlepseni proti tomu, co mam ted. Uvazuji
> o jednom z nasledujicich modulu:
> http://www.onetalent-gnss.com/ideas/wireless/denga10logbt
> http://www.onetalent-gnss.com/ideas/wireless/rappen10logbt
> Jinak data pro postprocesing by napr. pro okoli Brna mely byt zdarma
> dostupne ze site stanic EUREF:
> http://www.epncb.oma.be/_networkdata/stationlist.php
> pro Brno napr. tady:
> http://www.epncb.oma.be/_networkdata/siteinfo4onestation.php?station=TUBO_11503M001
>
>
> Moje dotazy do fora:
> - Hrali jste si nekdo s necim podobnym?
> - Meli byste chut a cas se nekdo do toho taky pustit?
>
> Diky,
> Petr
>
>
>
> From: Michele Bavaro [mailto:mbavaro na onetalent-gnss.com]
> Sent: Sunday, October 07, 2012 10:19 PM
> To: Petr Holub
> Subject: Re: a module for accurate mapping for OSM
>
> Hello Petr,
>
> Thanks for getting in touch!
>
> It will be very difficult to guarantee 1m accuracy (standalone real-time or differential post-processed) under dense
> foliage.
> Trees are well known to disrupt carrier phase information which is essential to achieve such accuracies.
> There is something about it on the German forum Kowoma:
> http://www.kowoma.de/gpsforum/viewtopic.php?f=1&t=3248&p=14992#p14992
>
> Denga10 and Rappen10 are not suitable. But their _LogBt or _LogWi version instead might work: they have a battery which
> will last a longer than 6hr, logging, and Bluetooth - or pretty much any other wireless communication system. Of course
> both have raw measurements but their carrier phase will be impaired under foliage as I wrote above.
> I am finalising the firmware in these days (today I had logging with fatfs and USB MSC running simultaneously finally)
> but -as it is quite experimental- I cannot really claim that is a "set and forget" kind of solution.
> Firmware is open though and if you have programming skills you may modify it to your needs.
> I am also working on enclosures... I have the bare boxes but I need to hand-tool them.
> If you are happy to do it by yourself I can make a discount:
> http://www.onetalent-gnss.com/announcements/contributorsgetafreereceiver
>
> Unfortunately in any case I cannot make you a lower price than 250EUR+VAT+shipping as I hand assemble the boards and I
> don't sell many of them so I cannot reduce the price by producing volumes.
>
> I would love to help you but I understand that compared to a 100EUR logger it's a lot of money to invest.
> By the way, all new Mediatek receivers have 10Hz and very high sensitivity... the new MTK3333 also has Glonass.
> ST Microelectronics has the STA8088FG which performs very well and it's very low cost.
> Not to mention of course the usual CSR GSD4E and Skytraq Venus..
> Have you looked at Fastrax, Locosys, and GlobalTop?
>
> I am very happy to help an enthusiastic mapper, please let me know if I can do something else for you.
>
> Best regards,
> Michele
>
>
>
>
>
> On 7 October 2012 18:52, Petr Holub <hopet na ics.muni.cz> wrote:
> Hello,
>
> I'm looking for a GNSS module that could improve precision of my
> mapping efforts for Openstreetmap - mainly mountainbike trails and
> hiking paths in the Czech Republic (http://www.mtbmap.cz/). Up to
> now, I'm using Sirf3-based Garmin 60CSx mounted on the MTB handlebar,
> and MTK3329-based Holux M-1000C logger switched to 10Hz, mounted to
> my MTB helmet. While Garmin 60CSx produces reasonably precise
> results while hiking open-air, it has significantly worse behavior
> in hilly forests and 1Hz operation is not sufficient for accurately
> tracking shape of paths when riding fast on my bike. Holux provides
> improves tracking of fast motion, but it has usually significantly
> worse accuracy (i.e., wanders more) despite being mounted on top
> of my helmet and thus having good sky view.
>
> Thus I'm looking for a reasonably priced (<400 EUR, ideally 200-300EUR)
> solution for more accurate logging of MTB trails, ideally at 4Hz or better
> and approx. 1m accuracy - obviously I don't need 1cm accuracy, but I'd
> like to have 1m accuracy even under forest foliage. I don't need precise
> real-time output (Garmin will work fine for real-time navigation;
> having, e.g., additional Bluetooth NMEA output to verify operation,
> would be nice for the module, but it is not conditio sine qua non).
> I assume to put the device on my helmet again, replacing the Holux
> logger - so I shouldn't be excessively large or heavy. An alternative
> solution would be to have the device in my backpack and only put the
> antenna onto the helmet. The device should keep working on a battery
> for at least 6hrs. The ideal workflow for me is to keep the device
> logging into its internal memory, come back home, download the raw
> log and post-process it using RTKLIB to achieve 1m log accuracy, without
> need for paying recurring costs (such as CZEPOS professional DGPS correction).
> I'm doing this effort as a hobbyist, thus minimizing operational costs
> is important.
>
> Is there some solution for this in your portfolio? I was looking into
> Denga10LogBt, but I'm not sure if it meets my requirements - to sum it
> up:
> - battery operated for at least 6 hours
> - internal RAW logging for later processing
> - 1m accuracy under foliage (50cm accuracy would be absolutely perfect)
> - 4Hz or higher frequency (about 10Hz is ideal)
> - either whole device or at least the antenna should be helmet-mountable
> - helmet-mountable part of the device (or complete device) needs to
> be weather-sealed and needs to have reasonable weight (I can try to
> build my own housing, but not sure...)
> - post-processing should avoid need for paid data (such as CZEPOS)
> - ideally use open-source software to process the data
>
> Maybe my wishes still can't be fulfilled, but I've just stumbled over
> your website and the devices really look promising...
>
> Thanks,
> Petr
>
>
>
>
zobrazit citaci
> nejsem si jist, zda si chces hrat s nekonvencnim merenim 2) nebo
> opravdu potrebujes jen lepsi klasicky pristroj 1).
> Nicmene problem lesa je predevsim vicecestne sireni signalu, utlum,
> terenni prekazky a voda po desti.
Jj, vim o tom - akorat bych se rad dostal tak daleko, jak by to
do rekneme 10.000 CZK investice slo.
zobrazit citaci
> 2) kodove mereni
> * frekvence vzorkovani signalu u kapesnich prijimacu neni problem 1hz,
> nikdy jsem se zatacenim nemel problem. Samozrejme v terenu vzdy
> existuje jista mira nejistoty/nepresnosti.
Dle mych zkusenosti hodne zalezi na rychlosti pohybu vs. pozadovane
presnosti. V zasade bych chtel neco, s tim se bude dat natrackovat
i tohle:
http://www.openstreetmap.org/?lat=49.24047&lon=16.60118&zoom=17&layers=M
(Soucasna metoda Holux M-1000C + Garmin 60CSx + hromada najetych
tras je dost otravna a stejne moc presna.)
zobrazit citaci
> * Garmin Vista co jsem mel byl pro mapovaci trackovani temer nepouzitelny
To se nedivim - mne uz tech loggeru rukama proslo par a zatim bych
rekl, ze Garmin 60CSx se Sirf3 chipsetem je zdaleka nejlepsi, co jsem
zatim mel (kupoval jsem ho z druhe ruky, protoze podle rady zahranicnich
testu je to prave otazka toho Sirf3 chipsetu, nez presli na Mediatek).
Co se Mediateku tyce, tak ten Holux M-1000C ma v sobe MTK-3329 (tentyz,
co ma Martin Kokes ve zminene Qstarz BT-Q1000X), ktery by na tom papirove
mel byt lepe nez Sirf3. V aute to funguje taky celkem dobre, ale vozim
ho i nahore na helme na kole (co nejmensi stineni signalu telem) a na tom
kole je to furt o kus horsi nez ta 60CSx s Sirfem.
Na druhou stranu to zjevne neni jen o chipsetu - v minulosti jsem pouzival
igotU GT-120, ktery ma sice taky Sirf3, ale byl o rad horsi ne Holux, a to
ve vsech aspektech.
zobrazit citaci
> * to o cem se pise nize v mailu je mereni fazove uplne odlisne od
> kodoveho, ma to sve vlastni problemy. Je hodne metod jak s tim
> pracovat...
> * abys mohl delat postprocessing potrebujes RINEX nebo podobny
> vystupni format a na korekce kdysi byl nejaky free sw, lze delat nad
> fazovym i kodovym merenim
> * samotne fazove mereni je nejednoznacne a ma problemy s prerusenim signalu
Ano, ty veci od OneTalent-GNSS jsou stavene na pouziti s RTKLIB
(http://www.rtklib.com/), coz je predpokladam to, co mas na mysli.
Jinak ten Rappen10LogBt je postaveny na NEO-6P, ktery to do jiste
miry umi delat i primo v sobe bez postprocesingu - uBlox tomu rika
PPP:
http://www.u-blox.com/en/precise-point-positioning-ppp.html
zobrazit citaci
> PS: jinak lesaci se touto problematikou docela casto bavi, napr:
> http://www.lesycr.cz/odborne-rady/granty-a-dotace/Documents/optimalizace_tds_pomoci_gps-web.pdf
Jj, nasel jsem i jine, napr.
http://warnell.forestry.uga.edu/warnell/bettinger/GPS/CJFE_33_1_149-157.pdf
http://warnell.forestry.uga.edu/warnell/bettinger/GPS/MCFNS_4_2_81-91.pdf
a dalsi.
zobrazit citaci
> Já jsem v autě dosáhl slušných výsledků s Qstarz BT-Q1000X na 5 Hz v kombinaci s funkcí Kalman Filter
> v http://www.efficasoft.com/gpsutilities/windowsmobile_professional.html. Největší gró tam asi dělá
> ten Kalman filtr. Možná že by šlo použít pro postprocessing toto:
> https://github.com/lacker/ikalman
Diky za tip - o Kalmanovic filtrovani jsem sice vedel, nicmene jsem si
myslel, ze mi to moc nepomuze - u toho Holuxe mam problem v tom, ze on
ma jakoby tendenci ustrelovat jakoby systematickou nikoli nahodnou chybou
(tj. ne ze by ty body byly rozhazene kolem nejakeho spravneho prumeru,
ale jsou ujete o nejak metry tam ci onam). Bohuzel nemam Windows Mobile,
s nimiz bych to mohl primo pouzivat, nicmene jsem narazil na
NMEA Processor, ktery by to mel taky zvladat:
http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=106662&whichpage=21
https://sites.google.com/site/victorpomortseff/nmea-processor
ale jeste ho budu muset trochu prozkoumat, co to vlastne umi.
zobrazit citaci
> co třeba tohle: http://gpspp.sakura.ne.jp/rtklib/rtklib_beagleboard.htm
> (viz první odkaz na pdf)
Beaglebord s RTKLIBem jsem videl - ale chtel jsem nejake reseni na cesty
do batohu, ne do zasuvky :) Navic bych uprednostnoval nekutit - mapovani
pro OSM mam primarne jako odreagovani, abych mel dobry duvod se dostat
do prirody :))
Petr
zobrazit citaci
> > Já jsem v autě dosáhl slušných výsledků s Qstarz BT-Q1000X na 5 Hz v kombinaci s funkcí Kalman
> Filter
> > v http://www.efficasoft.com/gpsutilities/windowsmobile_professional.html. Největší gró tam asi dělá
> > ten Kalman filtr. Možná že by šlo použít pro postprocessing toto:
> > https://github.com/lacker/ikalman
>
> Diky za tip - o Kalmanovic filtrovani jsem sice vedel, nicmene jsem si
> myslel, ze mi to moc nepomuze - u toho Holuxe mam problem v tom, ze on
> ma jakoby tendenci ustrelovat jakoby systematickou nikoli nahodnou chybou
> (tj. ne ze by ty body byly rozhazene kolem nejakeho spravneho prumeru,
> ale jsou ujete o nejak metry tam ci onam). Bohuzel nemam Windows Mobile,
> s nimiz bych to mohl primo pouzivat, nicmene jsem narazil na
> NMEA Processor, ktery by to mel taky zvladat:
> http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=106662&whichpage=21
> https://sites.google.com/site/victorpomortseff/nmea-processor
> ale jeste ho budu muset trochu prozkoumat, co to vlastne umi.
Takze - uchodit jsem to uchodil a Kalman filtrovani dela presne to,
co bych od neho cekal - odfiltruje tu "nahodnou chybu" (v uvozovkach
to pisu proto, ze to, co jsem vyse oznacil jako "systematickou chybu"
je ve skutecnosti taky nahodna, ale jina nez to kratkodobe driftovani.
Pokud chcete, muzu nekam vystavit priklad, jak to dopadlo.
Petr
Určitě, ukaž, zajímá mě to. Já si tenkrát dělal porovnání současného záznamu Mediateku na 5 Hz s Kalmanem a Sirfu na 1 Hz vestavěného v HP RX5910 a ten Mediatek vypadal definitivně lépe.
MK
----- Original Message -----
From: Petr Holub
[mailto:hopet na ics.muni.cz]
To: 'OpenStreetMap Czech Republic'
[mailto:talk-cz na openstreetmap.org]
Sent: Sun, 14 Oct 2012 08:16:40
+0200
Subject: Re: [Talk-cz] presnejsi trackovani pro OSM
zobrazit citaci
> > > Já jsem v autě dosáhl slušných výsledků s Qstarz BT-Q1000X na 5
> Hz v kombinaci s funkcí Kalman
> > Filter
> > > v
> http://www.efficasoft.com/gpsutilities/windowsmobile_professional.html.
> Největší gró tam asi dělá
> > > ten Kalman filtr. Možná že by šlo použít pro postprocessing toto:
> > > https://github.com/lacker/ikalman
> >
> > Diky za tip - o Kalmanovic filtrovani jsem sice vedel, nicmene jsem si
> > myslel, ze mi to moc nepomuze - u toho Holuxe mam problem v tom, ze on
> > ma jakoby tendenci ustrelovat jakoby systematickou nikoli nahodnou chybou
> > (tj. ne ze by ty body byly rozhazene kolem nejakeho spravneho prumeru,
> > ale jsou ujete o nejak metry tam ci onam). Bohuzel nemam Windows Mobile,
> > s nimiz bych to mohl primo pouzivat, nicmene jsem narazil na
> > NMEA Processor, ktery by to mel taky zvladat:
> > http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=106662&whichpage=21
> > https://sites.google.com/site/victorpomortseff/nmea-processor
> > ale jeste ho budu muset trochu prozkoumat, co to vlastne umi.
>
> Takze - uchodit jsem to uchodil a Kalman filtrovani dela presne to,
> co bych od neho cekal - odfiltruje tu "nahodnou chybu" (v uvozovkach
> to pisu proto, ze to, co jsem vyse oznacil jako "systematickou chybu"
> je ve skutecnosti taky nahodna, ale jina nez to kratkodobe driftovani.
> Pokud chcete, muzu nekam vystavit priklad, jak to dopadlo.
>
> Petr
>
>
> _______________________________________________
> Talk-cz mailing list
> Talk-cz na openstreetmap.org
> http://lists.openstreetmap.org/listinfo/talk-cz
>
zobrazit citaci
> Určitě, ukaž, zajímá mě to. Já si tenkrát dělal porovnání současného záznamu Mediateku na 5 Hz s
> Kalmanem a Sirfu na 1 Hz vestavěného v HP RX5910 a ten Mediatek vypadal definitivně lépe.
Takze 2 rychle priklady:
- Kalmanovske filtrovani - priklad ze Zamilce, Holux M-1000C (MTK3329),
10Hz na kole; Kalamnuv filtr udelan NMEAprocessorem (predtim zkonvertovano
do GPX GPSBabelem, protoze na tom puvodnim NMEA logu ten NMEAprocesor
padal):
http://arwen.ics.muni.cz/~hopet/tmp/osm-cz/kalman.zip
- Holux M-1000C (MTK3329) vs. Garmin 60CSx (Sirf3); nevybiral jsem nic
specialniho, vzal jsem log ze vcerejsi kratke vyjizdky na kole
http://arwen.ics.muni.cz/~hopet/tmp/osm-cz/60CSx_vs_Holux.zip
Znacna cast te trasy (nikoli cela) je projeta tam i zpet, takze je pekne videt,
i jak moc to lita mezi prujezdy.
Petr
Apropos, zapomnel jsem popsat soubory v tech ZIPech:
zobrazit citaci
> Takze 2 rychle priklady:
> - Kalmanovske filtrovani - priklad ze Zamilce, Holux M-1000C (MTK3329),
> 10Hz na kole; Kalamnuv filtr udelan NMEAprocessorem (predtim zkonvertovano
> do GPX GPSBabelem, protoze na tom puvodnim NMEA logu ten NMEAprocesor
> padal):
> http://arwen.ics.muni.cz/~hopet/tmp/osm-cz/kalman.zip
- 2012-09-08.gpx: puvodni mereni zaznamenane jako NMEA proud na Androidim
telefonu, prekonvertovane do GPX GPSBabelem
- 2012-09-08_kalman.gpx: data prohnana pres Kalmanovo filtrovani
zobrazit citaci
> - Holux M-1000C (MTK3329) vs. Garmin 60CSx (Sirf3); nevybiral jsem nic
> specialniho, vzal jsem log ze vcerejsi kratke vyjizdky na kole
> http://arwen.ics.muni.cz/~hopet/tmp/osm-cz/60CSx_vs_Holux.zip
> Znacna cast te trasy (nikoli cela) je projeta tam i zpet, takze je pekne videt,
> i jak moc to lita mezi prujezdy.
- 2012-10-13.gpx: Garmin 60CSx
- 2012-09-11_09-10-32.nmea: Holux M-1000C
Zdravi,
Petr
Ahoj,
nebude se doufam nikdo zlobit, kdyz vysledek shrnu i pro ostatni tak, ze:
1) kalmanuv filtr data trosku vyhladi, takze nejsou zubata
2) vyhlazeni se pohybuje pro potreby OSM v zanedbatelnych mezich, nebot
samotna chyba prijimace je radove daleko vetsi...
Takze data jsou pri rozumne urovni priblizeni (treba v JOSM) uplne
identicka. Pri hodne velkem zoomu je pak Kalman trochu min zubaty, ale
prakticky vzato to nic moc neprinasi.
Zajimave by to, IMO, bylo pouze tehdy, kdyz by to byla jedna z voleb
treba v JOSM a kdyz si clovek otevre GPXko, tak by se mu takhle
predfiltrovalo. Bylo by to hezke, ale nic vic, nic min :)
K
Dne 14.10.2012 22:34, Petr Holub napsal(a):
zobrazit citaci
> - 2012-09-08.gpx: puvodni mereni zaznamenane jako NMEA proud na Androidim
> telefonu, prekonvertovane do GPX GPSBabelem
> - 2012-09-08_kalman.gpx: data prohnana pres Kalmanovo filtrovani
Je videt, ze oba pristroje se s tim popasovaly vicemene velmi dobre a
skoro stejne!
Dne 14.10.2012 22:34, Petr Holub napsal(a):
zobrazit citaci
> - 2012-10-13.gpx: Garmin 60CSx
> - 2012-09-11_09-10-32.nmea: Holux M-1000C
zobrazit citaci
> Je videt, ze oba pristroje se s tim popasovaly vicemene velmi dobre a
> skoro stejne!
>
> Dne 14.10.2012 22:34, Petr Holub napsal(a):
> > - 2012-10-13.gpx: Garmin 60CSx
> > - 2012-09-11_09-10-32.nmea: Holux M-1000C
Z meho pohledu ne - ten Holux ma tak o 3-8m vetsi rozptyl nez ta 60CSx
(je to typicky videt na tech cestak projetych tam i zpet).
Petr
Ahoj!
zobrazit citaci
> Já jsem v autě dosáhl slušných výsledků s Qstarz BT-Q1000X na 5 Hz v kombinaci s funkcí Kalman Filter v http://www.efficasoft.com/gpsutilities/windowsmobile_professional.html. Největší gró tam asi dělá ten Kalman filtr. Možná že by šlo použít pro postprocessing toto:
> https://github.com/lacker/ikalman
>
> Nicméně pro ostré zatáčky v lese by pomohl jedině GPS v kombinaci s gyroskopem/akcelerometrem.
>
To by asi fungovalo v aute, ale na kole se obavam bude
gyroskop/akcelerometr dost zmateny...
(Hmm. a co teprv na konskym hrbetu...)
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
Mno já myslel, že gyroskop je právě gyroskopem od toho, aby zmatený nebyl. ;-) A že akcelerometr nefunguje jen v jedné ose.
Nicméně,když taková zařízení fungují ve všem možném od RC vrtulníků, přes foťáky, Wii, Segway, auta až po kosmické sondy, kola i koně, nebo jiné přerostlé psy by to určitě zvládlo...
MK
----- Original Message -----
From: Pavel Machek [mailto:pavel na ucw.cz]
To:
OpenStreetMap Czech Republic [mailto:talk-cz na openstreetmap.org]
Sent: Mon,
15 Oct 2012 14:35:00 +0200
Subject: Re: [Talk-cz] presnejsi trackovani pro
OSM
zobrazit citaci
> Ahoj!
zobrazit citaci
> Já jsem v autě dosáhl slušných výsledků s Qstarz BT-Q1000X
> na 5 Hz v kombinaci s funkcí Kalman Filter v
> http://www.efficasoft.com/gpsutilities/windowsmobile_professional.html.
> Největší gró tam asi dělá ten Kalman filtr. Možná že by šlo
> použít pro postprocessing toto:
> https://github.com/lacker/ikalman
>
>
> Nicméně pro ostré zatáčky v lese by pomohl jedině GPS v kombinaci s
> gyroskopem/akcelerometrem.
>
To by asi fungovalo v aute, ale na kole se
zobrazit citaci
> obavam bude
gyroskop/akcelerometr dost zmateny...
(Hmm. a co teprv na
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> konskym hrbetu...)
Pavel
--
(english)
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(cesky, pictures)
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_______________________________________________
Talk-cz
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Talk-cz na openstreetmap.org
http://lists.openstreetmap.org/listinfo/talk-cz
2012/10/15 Pavel Machek <pavel na ucw.cz>:
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> To by asi fungovalo v aute, ale na kole se obavam bude
> gyroskop/akcelerometr dost zmateny...
Oproti tomu ideální kombinace je při chůzi akcelerometr v botě, páč
tam je vždycky chvilka klidu, kdy se dá resetovat, takže to
nedriftuje… http://www.aetherczar.com/?p=2348
-- Petr Kadlec / Mormegil« zpět na výpis měsíce