RTK reference station (GNSS observation station)
I am conducting radio observations of the Global Navigation Satellite System (GNSS). The observed data is publicly available on the Internet through realtime streams and archives. As part of this realtime stream, I am also using the Radio Technical Commission for Maritime Services (RTCM) format, making it usable as a Real-Time Kinematic (RTK) reference station.
Please note that this equipment is intended for my research purposes, and there might be times when it is not available for use. Additionally, the operation beyond August 31, 2024, is yet to be determined.
Reference: RTK reference station (old page)
(1) Connection information
The information available consists of realtime streams and archive data.
This realtime stream utilizes NTRIP (Networked Transport of RTCM via Internet Protocol) format, which is a common method for publishing GNSS observation data on the internet.
Anyone can freely access and use this observation data without prior notification. When citing this data, please use the URL of this page.
The connection details are as follows:
|format||NTRIP version 1|
|user name||none (please leave blank)|
|password||none (please leave blank)|
(2) RTCM format stream
The realtime stream consists of two formats: RTCM 3.2 format used for applications like RTK, and receiver-specific raw data format used for positioning analysis. The mount points for the RTCM format realtime stream are as follows:
|satellite system||GPS, GAL, GLO, QZS, BDS, IRN||GPS, GAL, GLO, QZS, BDS|
|frequency band||L1, L2, L5||L1, L2|
|receiver||NovAtel OEM729||u-blox ZED-F9P|
The antenna coordinates are as follows: 34.4401061 degrees North latitude, 132.4147804 degrees East longitude, and an ellipsoidal height of 233.362 meters. These antenna coordinates are automatically configured using RTCM message type 1005. This coordinate set was determined using the “Hiroshima 2A” electronic reference point provided by the Geospatial Information Authority of Japan at March 13 to 17, 2021. The antenna used is the Javad GrAnt-G5T.
The RTCM messages are as follows:
|message type||message content||OEM7 mount point||F9P mount point|
|1033||Receiver and antenna descriptor||1||1|
|1045||Galileo Ephemeris F/Nav (Free Navigation)||onchanged|
|1046||Galileo Ephemeris I/Nav (Integrity Navigation)||onchanged||onchanged|
|1230||GLONASS L1/L2 code bias||onchanged||onchanged|
In this context, the number 1 signifies a message interval of 1 second, and “onchanged” indicates delivering the data once it has been received. “Ephemeris” refers to information such as satellite coordinates and time that satellites broadcast. MSM7 (Full pseudo-ranges, carrier phases, Doppler, and signal strength, high resolution) represents the observed satellite signals.
To automatically configure the antenna phase center for Precise Point Positioning (PPP), the message type 1033 is derivered. However, due to the limitation of not being able to deliver messages with spaces, and as a result, not being able to accurately represent antenna names, the automatic configuration for this purpose is currently not possible.
(3) Receiver raw data stream
Realtime streams and their archives are on public. The mount points and archive links for these streams are as follows:
|signal name||(multiple)||(multiple)||QZSS L6D||QZSS L6E||Galileo E6B||BeiDou B2b|
|raw data name||(multiple)||UBX-RXM-RAWX|
|QZSS L6 Raw (0x10)||QZSS L6 Raw (0x10)||GALCNAVRAWPAGE||BDSRawB2b|
- Use of QZS L6 Tool with own observation equipment
- Real-time stream of Allystar receiver
- Galileo HAS live stream
- BeiDou B2b signal livestream
Observation data archive
The raw data can be retrieved with web browsers or command-line tools like
curl. The directory arrangement is as follows:
YYYYMM/ YYYYMMDDa.ext YYYYMMDDb.ext ... YYYYMMDDw.ext YYYYMMDDx.ext
In the format, YYYY represents the year, MM represents the month, DD represents the day, the lowercase English letters from ‘a’ to ‘x’ represent codes for the hours from 00:00 to 23:00, and ext represent the raw date extension.
Please note that the time is in UTC (Coordinated Universal Time).