RTK reference station (old page)


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 portntrip.phys.info.hiroshima-cu.ac.jp:80
Service typeNTRIP Caster (version 1)
User namenone (blank)
ProtocolRTCM 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 pointOEM7F9PROV
ProtocolRTCM 3.2RTCM 3.2RTCM 3.2
Frequency bandL1, L2, and L5L1 and L2L1
Antenna positionLatitude 34.4401061 N
Longitude 132.4147804 E
Ellipsoidal height 233.362 m
same as leftLatitude 34.44010 N
Longitude 132.41478 E
Ellipsoidal height 232.4 m
EquipmentRTKLIB 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
Commentfor reference stationfor reference stationfor 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:

1005Station coordinates11
1019GPS Ephemerisononon
1020GLONASS Ephemerisononon
1033Receiver and antenna descriptor11
1041NavIC Ephemerison
1042BDS Ephemerisonon
1044QZSS Ephemerisononon
1045Galileo Ephemeris F/Nav (Free Navigation)on
1046Galileo Ephemeris I/Nav (Integrity Navigation)ononon
1077GPS MSM7110.2
1087GLONASS MSM7110.2
1097Galileo MSM7110.2
1107SBAS MSM710.2
1117QZSS MSM7110.2
1127BeiDou MSM711
1137NavIC MSM71
1230GLONASS L1/L2 code biasononon

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: