[Talk-cz] presnejsi trackovani pro OSM

[Petr Holub]

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