Anyone here with RTKLIB knowledge who could share some knowledge?


as the required GPS receiver modules (like the u-blox NEO M8N) are getting really cheap, I’m wondering if the following would work somehow:

I could place one Raspberry Pi with GPS receiver next to my house. Maybe with a GPS antenna placed onto the roof.

Then my plan is to carry one Raspberry Pi, powered via power bank, around with me to, for example, log streets and other tracks.

After arriving back home I want to take the data logged on my roof and the data logged on my “portable Raspberry” and somehow merge them together into an “improved precision” GPS log.

What would I need to do this? Is it possible at all?

Important sidenote: I don’t have Windows at all and I won’t install Windows anywhere. So I would have to use the CLI tools from RTKLIB.

Thanks in advance.

I haven’t done this, but it appears possible following the method at , controlled by the CLI to RTKLIB which I haven’t tried to set up.

I’ve been going down the route of using a ublox ZED-F9P with a free realtime NTRIP feed. My nearest free feed is 50 miles away, which means that it is mostly in the DM accuracy range, but much improved precision. However my setup leaves much to be desired: Ardusimple simpleRTK2Blite + Bluetooth → Android tablet → WiFi → IOS phone. The Android app feeds NTRIP data and logs tracks. It’s awkward to setup and fragile to run. Then antenna is mounted on a paint can lid for the ground plane. I’m still experimenting with a better method.

I’ve worked with the NEO M8U series on vehicles, and they have nearly the same precision capability when paired with a nearby base station.

I think most uses within OSM are for more precise warping of drone captured imagery and therefore people tend to be more interested in capturing precise control points rather than dynamic position.

There are certainly a number of people who have some experience. We played around with a setup at Avignon at the end of SotM-Fr 3 years ago. This was for someone to understand the setup in case they needed to use it when on a HOT mission. It was my idea to use it to geolocate a tree as an example. The original idea was to find a known survey point to locate the base station, but time was against that.

We used two laptops with the ublox chipset. From memory it took some time to be satisfied that a good signal was being received from the base, so monitoring on a PC was essential.

There was also a talk at SotM-FR-17 so I imagine this may have been discussed at other meetings.

I finally got my rig working well enough to tackle mapping a path in a park under heavy tree cover - with enough pine trees that even the off-leaf ESRI Clarity imagery didn’t show much of the trail. I’m pretty happy with the results: compared with the conventional GPS where traces in opposite directions differed by 15 meters. Most were within a meter of each other when under tree cover, so I feel confident that it is close to the actual trail which represents the state outline.

Are there already users here who are familiar with the ZEF-F9P?
A few days ago I bought an Ardusimple RTK Handheld Surveyor Kit. It has a u-blox ZEF-F9P built in.

I can achieve a simple on-the-go RTK accuracy of a few centimetres with the apps Lefebure NTRIP Client or SW Maps with SAPOS data Berlin or Brandenburg and track recording in Locus Pro. But you need a constant connection to the internet, and that is not always available where I want to be on the road.

That’s why I would prefer to save the raw data in UBX format, convert it to RINEX and then use RTKLib to convert it into accurate GPS track data. Unfortunately, I fail at this and don’t know what I have to change. RTKLib obviously can’t do anything with my UBX files for the conversion to RINEX.

I would like to discuss with someone who knows how to do this. What is wrong with my UBX-files?