RTK reference station


A RTK (realtime kinematic) reference station is in operation at Hiroshima City University.

RTK is a method that aims at positioning with a precision of several centimeters at a mobile station using GNSS radio wave observation results at a “reference station” with known latitude and longitude. GNSS signal observation results at the reference station are transmitted to the mobile station via the Internet or mobile radio communication. On the other hand, the GNSS signal is also observed at the mobile station, and the uncertainty of the positioning result at the mobile station can be reduced by correcting the observation result at the mobile station or elsewhere.

Real-time centimeter-order positioning can be expected using the observation data of the RTK reference station. For real-time positioning with the observation data, you may need a receiver measuring the carrier phase and an internet connection.

The observation data can be used for free without any prior notice. Please note that the service may be interrupted due to the software updates, equipment failures, power outages, and so on. The observation data cannot be used for official surveying.

RTK reference station

RTK would be available at a location about 10 km from the reference station. You may use the observation data in most of places of central Hiroshima.

circle of 10 km from the reference station

© OpenStreetMap contributors

You may find more RTK reference stations at Volunteer RTK reference stations other than this reference station.

Information for connection

Details are as follows:

address and port ntrip.phys.info.hiroshima-cu.ac.jp:80
Service type NTRIP Caster (version 1)
User name none (blank)
Password none(blank)
Protocol RTCM 3.2

Following mount points are in public. Please use the mount point of OEM7 or F9P as an RTK reference station. Tutorial of using this reference station is also available.

Mount point OEM7 F9P ROV
Protocol RTCM 3.2 RTCM 3.2 RTCM 3.2
Frequency band L1, L2, and L5 L1 and L2 L1
Antenna position Latitude 34.4401061 N
Longitude 132.4147804 E
Ellipsoidal height 233.362 m
same as left Latitude 34.44010 N
Longitude 132.41478 E
Ellipsoidal height 232.4 m
Equipment RTKLIB 2.4.3b34
u-blox ZED-F9P
Javad GrAnt-G5T
RTKLIB 2.4.3b34
NovAtel OEM729
Javad GrAnt-G5T
RTKLIB 2.4.3b34
u-blox NEO-M8T (Emlid Reach)
Beitian BT-200
Comment for reference station for reference station for positioning test

Mount point F9PR is also broadcasted for the u-blox raw message regarding the mount point F9P.

The antenna positions were determined using the Hiroshima 2A station data of GSI of Japan during March 13rd - 17th 2021 (updated on 2021-03-27). The antennas are on the top of the Information Processing Center at Hiroshima City University (3-4-1 Ozuka-Higashi, Asa-Minami, Hiroshima, Japan).

The RTCM messages broadcasted from the server are as follows:

Type Description OEM7 F9P ROV
1005 Station coordinates 1 1
1019 GPS Ephemeris on on on
1020 GLONASS Ephemeris on on on
1033 Receiver and antenna descriptor 1 1
1041 NavIC Ephemeris on
1042 BDS Ephemeris on on
1044 QZSS Ephemeris on on on
1045 Galileo Ephemeris F/Nav (Free Navigation) on
1046 Galileo Ephemeris I/Nav (Integrity Navigation) on on on
1077 GPS MSM7 1 1 0.2
1087 GLONASS MSM7 1 1 0.2
1097 Galileo MSM7 1 1 0.2
1107 SBAS MSM7 1 0.2
1117 QZSS MSM7 1 1 0.2
1127 BeiDou MSM7 1 1
1137 NavIC MSM7 1
1230 GLONASS L1/L2 code bias on on on

MSM7=Full pseudo-ranges, carrier phases, Doppler and signal strength, high resolution

Tutorial is presented for using famous freeware RTKLIB.

Observation data archive

You can obtain the archive data from below address: