@kucai

Anybody got any idea if positions using averaged dual band gps phones (example Mi 8 or newer) can approach the decimeter level comparable to this board?

smartphones usually have a bad gnss antenna. You can look at this articles:

https://www.researchgate.net/project/Benchmark-of-smartphone-Xiaomi-Mi8-raw-GNSS-data-processing-solutions

https://rtklibexplorer.wordpress.com/?s=xiaomi

Hi, If you want to build your own Rover, there is some documentation (in french) here : https://docs.centipede.fr/docs/make_rover/materiel.html

Or you can buy some ready to use rovers from company like Sparkfun (RTK Surveyor, RTK Express).

I have build my own “dirty” logger, based on this work : https://github.com/PaulZC/F9P_RAWX_Logger

@grin Sure, http://centipede.fr and the caster is caster.centipede.fr, port number : 2101

Hi!

If you want to build your own base station, I wrote some code that could help you : https://github.com/Stefal/rtkbase In France we now have an open gnss network with about 200 base stations.

@AkuAnakTimur, could you test it ?

Hi! For the rear camera, you will have to add these parameters: --interpolate_directions --offset_angle 180

I’ve uploaded some WildAtlanticWay images a long time ago, 2015 I think. :-)

Hi! There are some BlueGps forks. I have one which works:

https://github.com/Stefal/bluegnss4droid (beta apk available)

It’s not perfect, and I had some crashes with it, but it’s open source, so anybody could fix the remaining bugs and publish it on F-droid.

@kgjenkins that makes sense. I’d like we can embed images directly on the osm.org servers. After a few years a big part of diary images are not correctly linked anymore.

@kgjenkins It works here. If you use some ads blocker or privacy addon inside your browser, check them.

I forgot to say that now, you can open RTKLib .pos files inside Josm. It helps me a lot : https://josm.openstreetmap.de/ticket/17829

@Alexey

Nothing new since this diary, but there are some tickets in Josm to recognize single/float/fix inside nmea and gpx files. That’s a good start. https://josm.openstreetmap.de/ticket/20600 https://josm.openstreetmap.de/ticket/20601

Hi Adrian,

Just to let you know that most base station on the centipede network use RTKBase, which is developped by …. an Osm Contributor… me :-)

@ndrw6 The rover was about 4km from the base station. With dual frequency receivers (base + rover) you can get a very good accuracy, up to 60km. The rover was a Zed-F9P with an arduino-like (Adafruit Feather M0 Adalogger). You can’t post-process a gpx, because all the useful informations are already gone. You can post process a base/rover setup or use them in real-time. I usually post-process, because I can test everything I want with RTKLib, and I don’t have to worry if my phone doesn’t receive the base data.

@Glassman Sorry, but I don’t know any low cost dual-frequency gnss receiver ready to use (with battery, case, bluetooth….). You have to build one yourself. When you have such a receiver, you can use it in realtime or only log the raw data and postprocess later. In realtime, you can use the receiver internal engine if you feed it with the base data, or the android app Rtkgps+ (it’s not 100% compatible with the F9P). This is a Rtkgps+ that “should” work with the F9P : https://github.com/jancelin/RtkGps/releases

Je ne sais pas. En tout cas, elle est visible ici : https://cycling.waymarkedtrails.org/#?map=8!46.9647!-1.3455

La relation master est celle-ci : osm.org/relation/4774799

Depuis celle-ci, on retrouve les différents morceaux comme celui-là par exemple : osm.org/relation/4840316

Bonjour Clément,

Interessant tout ça !! Je pense que ce que fait jungle bus devrait t’interesser aussi :

https://junglebus.io/

@Cameron Shorter Your draft is very interesting. I will follow it and the proj mailing list too.

@SimonPoole

we are using sources that are not actually using WGS84 and are offset to it

Exactly! I think that the first thing to do is a “state of the aerial imagery”. We have to know where the data are not using WGS84 coordinates, and the first step is to add some reference marks in every country with high res imagery: osm.wiki/Survey_points_on_aerial_imagery

@Warin61 What do you mean with “plate tectonic references”? There are 2 Coordinate Reference System type: Earth fixed (WGS84), and plate fixed (local datum like GDA94, NAD83, ETRS89 ….) The problem is that Osm is mixing the 2 types: Plate fixed coordinates in a earth fixed database.

If the GNSS receiver you use today is not accurate, some recent smartphones include a dual frequency receiver. Sub-meter accuracy in our pocket is just a matter of a few years.

@Harry Wood I had completely forgotten this April fool :-)

If we do nothing with the Australian data, we will see Osm contributors going to waste thousands of hours fixing everything with GDA2020 aerial imagery whereas they could use this time to add new data. I think it’s a big concern.

Here is a 1.8m offset:

Très intéressant ! N’hésite pas à faire d’autres retours lors des prochaines sessions.

As this gnss station is in the IGS network, we can download the observation data, and then use an online service to compute a PPP solution. The AUSPOS service gives back the coordinate with several datums. Here are the results from 2018-03-31 with GDA94, IRTF14(2018) and GDA2020 datums.

I’m more and more confident that this aerial imagery isn’t using an actual WGS84 datum…like the french aerial imagery, and potentialy many others.