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 <ho...@ics.muni.cz>: > 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:mbav...@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 <ho...@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@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-cz _______________________________________________ Talk-cz mailing list Talk-cz@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-cz