Wrocław: high precision GNSS tracks

Alexey Vazhnov · 2021-01-17 00:37:11

I'm creating GPX tracks near Wrocław, because some of villages have no any track available to check satellite imagery offset.

I found that Wrocław has a station LEICA GR50 from ASG by EUPOS: http://www.asgeupos.pl/index.php?wpg_ty … sub=ref_st

How can I use the signal of this station to create high quality GPX tracks?

Should I use any of RTKLIB-compatible GPS devices?

Mateusz Konieczny · 2021-01-17 14:44:37

Note that in Poland geoportal.gov.pl aerial imagery is so good that it can be used to align other aerial imagery.

Alexey Vazhnov wrote:

How can I use the signal of this station to create high quality GPX tracks?
Should I use any of RTKLIB-compatible GPS devices?

Sadly I have no idea at all here

RicoElectrico · 2021-01-17 15:09:27

ASG-EUPOS is now a paid service. It was free only in the beginning.

Alexey Vazhnov · 2021-01-18 23:53:14

Sad. I need accurate GNSS tracks not for checking satellite imagery offset only, but also for example to create good quality image sequences for Mapillary.

So, as an alternatives:

Buy device with multiband GNSS (L1 + L5 GPS)
Buy some RTK kit (SparkFun / u-blox ?), create own station and share diff into internet.
Buy temporary access from, for example, https://www.tpinet.pl/kup-dostep

First step looks good. Anyway I need more accurate GNSS to work with RTK.

Any other idea?

Last edited by Alexey Vazhnov (2021-01-19 00:05:52)

Alexey Vazhnov · 2021-03-07 15:06:37

I've ordered from digikey.pl:

SparkFun GPS-RTK-SMA ZED-F9P BREAKOUT — board with u-blox ZED-F9P
U-Blox ANN-MB-00-00 — active antenna, IP67

But there was no metal ground plane which is highly recommended by u-blox. I hope, any piece of metal will be fine for this.

Alexey Vazhnov · 2021-03-26 10:52:19

My precious arrived!

I had to pay import tax 290 PLN in addition to shop price 1170 PLN…

RicoElectrico · 2021-03-26 11:54:45

That's quite a lot of money.
Do you know of any cheap standalone L1+L2 receivers? In open sky conditions they are pretty good, as tested by some Xiaomi phone users on our FB group.
But I don't want to buy a phone just to record tracks.

Alexey Vazhnov · 2021-03-26 12:10:15

RicoElectrico wrote:

Do you know of any cheap standalone L1+L2 receivers?

I don't know.

I saw some cheap "multiband" modules on aliexpress, but I don't believe they are really multiband. I think it is better to take some old used u-blox NEO-M8* / NEO-M9* modules than to buy fake "multiband" module with unknown precision. As I understand, it is better to use L1 receiver with correction than multiband receiver without correction data.

You can take a look at https://rtklibexplorer.wordpress.com , he is "exploring precision GPS/GNSS with RTKLIB open source software and low-cost u-blox GNSS receivers".

Also you can take my module when you need it. I'm in Wrocław

Last edited by Alexey Vazhnov (2021-03-26 12:12:33)

SK53 · 2021-03-26 12:22:58

People I know on OSM using RTK include Jean-Guilhem Caiton (jgc) with ublox modules in France & in the UK both Russss and Firefishy have recently acquired them. There's also a thread in this forum in Russian on RTK. It's possible that sharing experience & advice would be useful. I felt that perhaps this was something a national association could invest in: however, in the UK we now have accurate open data on cadastral parcels which fulfills the purpose of high-quality image alignment.

MikeN · 2021-03-31 13:17:40

I used a US 1 gallon paint can lid as the ground plane. It is very close to the recommended size.

Alexey Vazhnov · 2021-04-04 09:17:10

MikeN wrote:

I used a US 1 gallon paint can lid as the ground plane. It is very close to the recommended size.

I'm using something similar, thank you!

I solved problem with GPSBabel: https://help.openstreetmap.org/question … -by-radius
So now I have a script to convert all NMEA files into one GPX and filter them to remove some noise.

I'm satisfied with a quality of tracks even without correction. Maybe I will not use a correction, because wrong correction can create a align for all tracks (am I right in this?).

My current setup:

Receiver SparkFun GPS-RTK-SMA ZED-F9P
IP67 active antenna: U-Blox ANN-MB-00-00, with 5 meters cable…
Single board computer: i.MX53 Quick Start board (1 GB RAM), it uses 5V x 0.3-0.5A when running
Noname powerbank with 3x18650 and controller TPOWER TP4366
Rainproof bag https://www.sportarsenal.cz/brasny/art--310/

Ta-da! Here are the tracks: https://www.openstreetmap.org/user/Alex … %20zed-f9p

Started a wiki-page: https://wiki.openstreetmap.org/wiki/Use … NSS_traces

TODO:

Better metal ground plane
Current setup spends whole bag, I need to make it more compact
Better power supply: my SBC can eat more than 1A when initializing, and my powerbank switches off sometimes on start
Replace SBC with a simple logger
Add Bluetooth to have connection with Android smartphone

Last edited by Alexey Vazhnov (2021-04-04 16:35:38)

#1 2021-01-17 00:37:11

Wrocław: high precision GNSS tracks

#2 2021-01-17 14:44:37

Re: Wrocław: high precision GNSS tracks

#3 2021-01-17 15:09:27

Re: Wrocław: high precision GNSS tracks

#4 2021-01-18 23:53:14

Re: Wrocław: high precision GNSS tracks

#5 2021-03-07 15:06:37

Re: Wrocław: high precision GNSS tracks

#6 2021-03-26 10:52:19

Re: Wrocław: high precision GNSS tracks

#7 2021-03-26 11:54:45

Re: Wrocław: high precision GNSS tracks

#8 2021-03-26 12:10:15

Re: Wrocław: high precision GNSS tracks

#9 2021-03-26 12:22:58

Re: Wrocław: high precision GNSS tracks

#10 2021-03-31 13:17:40

Re: Wrocław: high precision GNSS tracks

#11 2021-04-04 09:17:10

Re: Wrocław: high precision GNSS tracks

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