RTK reference station (GNSS observation station)

Summary

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)

Realtime stream

(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:

itemcontent
addressntrip.phys.info.hiroshima-cu.ac.jp(165.242.117.17)
port80 (TCP)
formatNTRIP version 1
user namenone (please leave blank)
passwordnone (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:

mount pointOEM7F9P
satellite systemGPS, GAL, GLO, QZS, BDS, IRNGPS, GAL, GLO, QZS, BDS
frequency bandL1, L2, L5L1, L2
receiverNovAtel OEM729u-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 typemessage contentOEM7 mount pointF9P mount point
1005Station coordinates11
1019GPS Ephemerisonchangedonchanged
1020GLONASS Ephemerisonchangedonchanged
1033Receiver and antenna descriptor11
1041NavIC Ephemerisonchanged
1042BDS Ephemerisonchangedonchanged
1044QZSS Ephemerisonchangedonchanged
1045Galileo Ephemeris F/Nav (Free Navigation)onchanged
1046Galileo Ephemeris I/Nav (Integrity Navigation)onchangedonchanged
1077GPS MSM711
1087GLONASS MSM711
1097Galileo MSM711
1117QZSS MSM711
1127BeiDou MSM711
1137NavIC MSM71
1230GLONASS L1/L2 code biasonchangedonchanged

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:

mount point-F9PRCLASMADOCAHASB2B
receiverNovAtel
OEM729
u-blox
ZED-F9P
Allystar
HD9310C
Allystar
HD9310C
NovAtel
OEM729
Septentrio
mosaic-X5
signal name(multiple)(multiple)QZSS L6DQZSS L6EGalileo E6BBeiDou B2b
raw data name(multiple)UBX-RXM-RAWX
UBX-RXM-SFRBX
QZSS L6 Raw (0x10)QZSS L6 Raw (0x10)GALCNAVRAWPAGEBDSRawB2b
archive linkoem7f9pclasmadocahasb2b

The mount point of MADOCA is temporally stopped becase of the MADOCA-PPP receiver trouble (2024-05-07).

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).