Updating RTK reference station information

category: gnss
tags: rtk


For research purposes, I am conducting radio signal observations of the global navigation satellite system (GNSS). As an RTK reference station, this observation data is open to the public on the Internet to the extent that it does not interfere with research.

Up until now, I’ve updated my equipment and settings at least once every few days, at least once every two months. Since there have been many changes since the beginning, the contents of RTK reference station with a direct link on the top page have been updated.

Due to organizational changes, the operation after 2024-08-31 is undecided. I would like to do various experiments in the rest of the year.


At first, I started the satellite signal observation with Emlid Reach RTK (chipset is u-blox M8T) receiver and Tallysman TW4721 antenna. How to make RTK observation station has also been released.

I used this observation station to install a lightning sensor, experience equipment noise, experience flooding trouble, experience blockchain, install software defined radio (SDR), and experience dual frequency observation with u-blox ZED-F9P.

A survey grade antenna Javad GrAnt-G5T was obtained and I learned a lot of knowledge by using it. I didn’t have enough money to buy a survey class receiver at that time. I realized it was important to use a good antenna in the early days.

Then fortunately I got a survey grade receiver NovAtel OEM729 receiver. I used cheap and excellent receivers of Allystar HD9310 option C, Sony Spresense, Drogger VRSC, bynav C1-FS, Unicore Communications UM982, Septentrio mosaic-go CLAS, and Septentrio mosaic-go X5.

Here is the connection diagram for my current equipment:

GNSS signal observation

Due to the limited space of the observation station, I have frequently replaced the equipment. To date, the instruments in this space for the long term are the ZED-F9P receiver, the OEM729 receiver, and the HD9310 receiver. I’m running out of space, so I’ve installed a GNSS antenna at home, and I’m using the Internet, and I’m using these detached devices at work. In order to receive radiowaves for frequency stability analysis and SDR (software defined radio), it was essential to utilize the space at home where the antenna cable could be pulled in and it was air conditioned.

My interest has also changed from RTK to precise point positioning (PPP) and navigation message parsing. I changed the data archive format from RTCM to receiver raw data, because I mostly analyze the receiver raw data. Some of the recorded archive data is available on the Internet (Reference: RTK reference station observation data archive test release, Past observation data archive).

Internet distribution

On the other hand, Internet distribution work of observation data is easier than installation work that involves changing wiring, because it mainly involves software settings.

Using computer virtualization software, I operate software such as NTRIP (Networked Transport of RTCM via Internet Protocol) caster on Linux VM (virtual machine). Using a VM makes it easier to back up disk images and change computers, and minimizes the damage caused by software vulnerabilities.

In addition, using NFS (network file system) mounting of NAS (network attached storage), raw data is recorded by sharing the data area between the Internet distribution and web server VMs.

Observation station future

Due to the organizational change, GNSS observation in the current form can be performed until 2024-08-31. I don’t know at this point what will happen in the future.

This organizational change was intended to improve research and educational activities. However, due to the debt and egoism left by those who made more rules and enforced them, moral hazard occurred and the organization collapsed. It will never get better.

For those who are aiming to be university or graduate school students, or who are aiming to become university professors, not only education and research, but also the background of the organization is important. Time flies when you’re trying to live your life to the fullest. Take care of yourself, research well and live a more fulfilling life.